* [PATCH v6] Improve the performance of --num-threads -d 31
@ 2016-04-14 5:42 Zhou Wenjian
2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
2016-04-15 2:39 ` Minfei Huang
0 siblings, 2 replies; 9+ messages in thread
From: Zhou Wenjian @ 2016-04-14 5:42 UTC (permalink / raw)
To: kexec
v6:
1. address Atsushi Kumagai's comments about calculating and reserving memory
v5:
1. remove unused variable check_out
2. reset num_threads if memory is not enough
v4:
1. fix a bug caused by the logic
v3:
1. remove some unused variables
2. fix a bug caused by the wrong logic
3. fix a bug caused by optimising
4. improve more performance by using Minoru Usui's code
multi-threads implementation will introduce extra cost when handling
each page. The origin implementation will also do the extra work for
filtered pages. So there is a big performance degradation in
--num-threads -d 31.
The new implementation won't do the extra work for filtered pages any
more. So the performance of -d 31 is close to that of serial processing.
The new implementation is just like the following:
* The basic idea is producer producing page and consumer writing page.
* Each producer have a page_flag_buf list which is used for storing
page's description.
* The size of page_flag_buf is little so it won't take too much memory.
* And all producers will share a page_data_buf array which is
used for storing page's compressed data.
* The main thread is the consumer. It will find the next pfn and write
it into file.
* The next pfn is smallest pfn in all page_flag_buf.
Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
---
makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
makedumpfile.h | 38 ++++---
2 files changed, 210 insertions(+), 148 deletions(-)
diff --git a/makedumpfile.c b/makedumpfile.c
index fa0b779..a826321 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3481,9 +3481,8 @@ initial_for_parallel()
{
unsigned long len_buf_out;
unsigned long page_data_buf_size;
- unsigned long limit_size;
- int page_data_num;
- int i;
+ struct page_flag *current;
+ int i, j;
len_buf_out = calculate_len_buf_out(info->page_size);
@@ -3553,20 +3552,7 @@ initial_for_parallel()
#endif
}
- /*
- * get a safe number of page_data
- */
- page_data_buf_size = MAX(len_buf_out, info->page_size);
-
- limit_size = (get_free_memory_size()
- - MAP_REGION * info->num_threads) * 0.6;
-
- page_data_num = limit_size / page_data_buf_size;
-
- info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
-
- DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
- info->num_buffers);
+ info->num_buffers = PAGE_DATA_NUM * info->num_threads;
/*
* allocate memory for page_data
@@ -3579,6 +3565,7 @@ initial_for_parallel()
}
memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
+ page_data_buf_size = MAX(len_buf_out, info->page_size);
for (i = 0; i < info->num_buffers; i++) {
if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
MSG("Can't allocate memory for buf of page_data_buf. %s\n",
@@ -3588,6 +3575,36 @@ initial_for_parallel()
}
/*
+ * initial page_flag for each thread
+ */
+ if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
+ == NULL) {
+ MSG("Can't allocate memory for page_flag_buf. %s\n",
+ strerror(errno));
+ return FALSE;
+ }
+ memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
+
+ for (i = 0; i < info->num_threads; i++) {
+ if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
+ MSG("Can't allocate memory for page_flag. %s\n",
+ strerror(errno));
+ return FALSE;
+ }
+ current = info->page_flag_buf[i];
+
+ for (j = 1; j < PAGE_FLAG_NUM; j++) {
+ if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
+ MSG("Can't allocate memory for page_flag. %s\n",
+ strerror(errno));
+ return FALSE;
+ }
+ current = current->next;
+ }
+ current->next = info->page_flag_buf[i];
+ }
+
+ /*
* initial fd_memory for threads
*/
for (i = 0; i < info->num_threads; i++) {
@@ -3612,7 +3629,8 @@ initial_for_parallel()
void
free_for_parallel()
{
- int i;
+ int i, j;
+ struct page_flag *current;
if (info->threads != NULL) {
for (i = 0; i < info->num_threads; i++) {
@@ -3655,6 +3673,19 @@ free_for_parallel()
free(info->page_data_buf);
}
+ if (info->page_flag_buf != NULL) {
+ for (i = 0; i < info->num_threads; i++) {
+ for (j = 0; j < PAGE_FLAG_NUM; j++) {
+ if (info->page_flag_buf[i] != NULL) {
+ current = info->page_flag_buf[i];
+ info->page_flag_buf[i] = current->next;
+ free(current);
+ }
+ }
+ }
+ free(info->page_flag_buf);
+ }
+
if (info->parallel_info == NULL)
return;
@@ -7075,11 +7106,11 @@ void *
kdump_thread_function_cyclic(void *arg) {
void *retval = PTHREAD_FAIL;
struct thread_args *kdump_thread_args = (struct thread_args *)arg;
- struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
+ volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
+ volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
struct cycle *cycle = kdump_thread_args->cycle;
- int page_data_num = kdump_thread_args->page_data_num;
- mdf_pfn_t pfn;
- int index;
+ mdf_pfn_t pfn = cycle->start_pfn;
+ int index = kdump_thread_args->thread_num;
int buf_ready;
int dumpable;
int fd_memory = 0;
@@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
kdump_thread_args->thread_num);
}
- while (1) {
- /* get next pfn */
- pthread_mutex_lock(&info->current_pfn_mutex);
- pfn = info->current_pfn;
- info->current_pfn++;
- pthread_mutex_unlock(&info->current_pfn_mutex);
-
- if (pfn >= kdump_thread_args->end_pfn)
- break;
-
- index = -1;
+ /*
+ * filtered page won't take anything
+ * unfiltered zero page will only take a page_flag_buf
+ * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
+ */
+ while (pfn < cycle->end_pfn) {
buf_ready = FALSE;
+ pthread_mutex_lock(&info->page_data_mutex);
+ while (page_data_buf[index].used != FALSE) {
+ index = (index + 1) % info->num_buffers;
+ }
+ page_data_buf[index].used = TRUE;
+ pthread_mutex_unlock(&info->page_data_mutex);
+
while (buf_ready == FALSE) {
pthread_testcancel();
-
- index = pfn % page_data_num;
-
- if (pfn - info->consumed_pfn > info->num_buffers)
+ if (page_flag_buf->ready == FLAG_READY)
continue;
- if (page_data_buf[index].ready != 0)
- continue;
-
- pthread_mutex_lock(&page_data_buf[index].mutex);
-
- if (page_data_buf[index].ready != 0)
- goto unlock;
-
- buf_ready = TRUE;
+ /* get next dumpable pfn */
+ pthread_mutex_lock(&info->current_pfn_mutex);
+ for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
+ dumpable = is_dumpable(
+ info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
+ pfn,
+ cycle);
+ if (dumpable)
+ break;
+ }
+ info->current_pfn = pfn + 1;
- page_data_buf[index].pfn = pfn;
- page_data_buf[index].ready = 1;
+ page_flag_buf->pfn = pfn;
+ page_flag_buf->ready = FLAG_FILLING;
+ pthread_mutex_unlock(&info->current_pfn_mutex);
+ sem_post(&info->page_flag_buf_sem);
- dumpable = is_dumpable(
- info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
- pfn,
- cycle);
- page_data_buf[index].dumpable = dumpable;
- if (!dumpable)
- goto unlock;
+ if (pfn >= cycle->end_pfn) {
+ info->current_pfn = cycle->end_pfn;
+ page_data_buf[index].used = FALSE;
+ break;
+ }
if (!read_pfn_parallel(fd_memory, pfn, buf,
&bitmap_memory_parallel,
@@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
if ((info->dump_level & DL_EXCLUDE_ZERO)
&& is_zero_page(buf, info->page_size)) {
- page_data_buf[index].zero = TRUE;
- goto unlock;
+ page_flag_buf->zero = TRUE;
+ goto next;
}
- page_data_buf[index].zero = FALSE;
+ page_flag_buf->zero = FALSE;
/*
* Compress the page data.
@@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
page_data_buf[index].size = info->page_size;
memcpy(page_data_buf[index].buf, buf, info->page_size);
}
-unlock:
- pthread_mutex_unlock(&page_data_buf[index].mutex);
+ page_flag_buf->index = index;
+ buf_ready = TRUE;
+next:
+ page_flag_buf->ready = FLAG_READY;
+ page_flag_buf = page_flag_buf->next;
}
}
-
retval = NULL;
fail:
@@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
struct page_desc pd;
struct timeval tv_start;
struct timeval last, new;
- unsigned long long consuming_pfn;
pthread_t **threads = NULL;
struct thread_args *kdump_thread_args = NULL;
void *thread_result;
- int page_data_num;
+ int page_buf_num;
struct page_data *page_data_buf = NULL;
int i;
int index;
+ int end_count, consuming;
+ mdf_pfn_t current_pfn, temp_pfn;
if (info->flag_elf_dumpfile)
return FALSE;
@@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
goto out;
}
- res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
- if (res != 0) {
- ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
- strerror(res));
- goto out;
- }
-
res = pthread_mutex_init(&info->filter_mutex, NULL);
if (res != 0) {
ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
@@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
end_pfn = cycle->end_pfn;
info->current_pfn = start_pfn;
- info->consumed_pfn = start_pfn - 1;
threads = info->threads;
kdump_thread_args = info->kdump_thread_args;
- page_data_num = info->num_buffers;
+ page_buf_num = info->num_buffers;
page_data_buf = info->page_data_buf;
+ pthread_mutex_init(&info->page_data_mutex, NULL);
+ sem_init(&info->page_flag_buf_sem, 0, 0);
- for (i = 0; i < page_data_num; i++) {
- /*
- * producer will use pfn in page_data_buf to decide the
- * consumed pfn
- */
- page_data_buf[i].pfn = start_pfn - 1;
- page_data_buf[i].ready = 0;
- res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
- if (res != 0) {
- ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
- strerror(res));
- goto out;
- }
- }
+ for (i = 0; i < page_buf_num; i++)
+ page_data_buf[i].used = FALSE;
for (i = 0; i < info->num_threads; i++) {
kdump_thread_args[i].thread_num = i;
kdump_thread_args[i].len_buf_out = len_buf_out;
- kdump_thread_args[i].start_pfn = start_pfn;
- kdump_thread_args[i].end_pfn = end_pfn;
- kdump_thread_args[i].page_data_num = page_data_num;
kdump_thread_args[i].page_data_buf = page_data_buf;
+ kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
kdump_thread_args[i].cycle = cycle;
res = pthread_create(threads[i], NULL,
@@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
}
}
- consuming_pfn = start_pfn;
- index = -1;
+ end_count = 0;
+ while (1) {
+ consuming = 0;
- gettimeofday(&last, NULL);
+ /*
+ * The basic idea is producer producing page and consumer writing page.
+ * Each producer have a page_flag_buf list which is used for storing page's description.
+ * The size of page_flag_buf is little so it won't take too much memory.
+ * And all producers will share a page_data_buf array which is used for storing page's compressed data.
+ * The main thread is the consumer. It will find the next pfn and write it into file.
+ * The next pfn is smallest pfn in all page_flag_buf.
+ */
+ sem_wait(&info->page_flag_buf_sem);
+ gettimeofday(&last, NULL);
+ while (1) {
+ current_pfn = end_pfn;
- while (consuming_pfn < end_pfn) {
- index = consuming_pfn % page_data_num;
+ /*
+ * page_flag_buf is in circular linked list.
+ * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
+ * page_flag_buf list.
+ * consuming is used for recording in which thread the pfn is the smallest.
+ * current_pfn is used for recording the value of pfn when checking the pfn.
+ */
+ for (i = 0; i < info->num_threads; i++) {
+ if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
+ continue;
+ temp_pfn = info->page_flag_buf[i]->pfn;
- gettimeofday(&new, NULL);
- if (new.tv_sec - last.tv_sec > WAIT_TIME) {
- ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
- goto out;
- }
+ /*
+ * count how many threads have reached the end.
+ */
+ if (temp_pfn >= end_pfn) {
+ info->page_flag_buf[i]->ready = FLAG_UNUSED;
+ end_count++;
+ continue;
+ }
- /*
- * check pfn first without mutex locked to reduce the time
- * trying to lock the mutex
- */
- if (page_data_buf[index].pfn != consuming_pfn)
- continue;
+ if (current_pfn < temp_pfn)
+ continue;
- if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
- continue;
+ consuming = i;
+ current_pfn = temp_pfn;
+ }
- /* check whether the found one is ready to be consumed */
- if (page_data_buf[index].pfn != consuming_pfn ||
- page_data_buf[index].ready != 1) {
- goto unlock;
+ /*
+ * If all the threads have reached the end, we will finish writing.
+ */
+ if (end_count >= info->num_threads)
+ goto finish;
+
+ /*
+ * If the page_flag_buf is not ready, the pfn recorded may be changed.
+ * So we should recheck.
+ */
+ if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
+ gettimeofday(&new, NULL);
+ if (new.tv_sec - last.tv_sec > WAIT_TIME) {
+ ERRMSG("Can't get data of pfn.\n");
+ goto out;
+ }
+ continue;
+ }
+
+ if (current_pfn == info->page_flag_buf[consuming]->pfn)
+ break;
}
if ((num_dumped % per) == 0)
print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
- /* next pfn is found, refresh last here */
- last = new;
- consuming_pfn++;
- info->consumed_pfn++;
- page_data_buf[index].ready = 0;
-
- if (page_data_buf[index].dumpable == FALSE)
- goto unlock;
-
num_dumped++;
- if (page_data_buf[index].zero == TRUE) {
+
+ if (info->page_flag_buf[consuming]->zero == TRUE) {
if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
goto out;
pfn_zero++;
} else {
+ index = info->page_flag_buf[consuming]->index;
pd.flags = page_data_buf[index].flags;
pd.size = page_data_buf[index].size;
pd.page_flags = 0;
@@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
*/
if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
goto out;
-
+ page_data_buf[index].used = FALSE;
}
-unlock:
- pthread_mutex_unlock(&page_data_buf[index].mutex);
+ info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
+ info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
}
-
+finish:
ret = TRUE;
/*
* print [100 %]
@@ -7463,15 +7509,9 @@ out:
}
}
- if (page_data_buf != NULL) {
- for (i = 0; i < page_data_num; i++) {
- pthread_mutex_destroy(&page_data_buf[i].mutex);
- }
- }
-
+ sem_destroy(&info->page_flag_buf_sem);
pthread_rwlock_destroy(&info->usemmap_rwlock);
pthread_mutex_destroy(&info->filter_mutex);
- pthread_mutex_destroy(&info->consumed_pfn_mutex);
pthread_mutex_destroy(&info->current_pfn_mutex);
return ret;
@@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
num_dumped++;
if (!read_pfn(pfn, buf))
goto out;
+
filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
/*
@@ -10201,7 +10242,6 @@ out:
return free_size;
}
-
/*
* Choose the less value of the three below as the size of cyclic buffer.
* - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
@@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
* free memory for safety.
*/
limit_size = get_free_memory_size() * 0.6;
+
+ /*
+ * Recalculate the limit_size according to num_threads.
+ * And reset num_threads if there is not enough memory.
+ */
+ if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
+ MSG("There isn't enough memory for %d threads.\n", info->num_threads);
+
+ info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
+ MSG("--num_threads is set to %d.\n", info->num_threads);
+ }
+
+ limit_size = limit_size - THREAD_REGION * info->num_threads;
+
/* Try to keep both 1st and 2nd bitmap at the same time. */
bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
diff --git a/makedumpfile.h b/makedumpfile.h
index e0b5bbf..322d31b 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -44,6 +44,7 @@
#include "print_info.h"
#include "sadump_mod.h"
#include <pthread.h>
+#include <semaphore.h>
/*
* Result of command
@@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
* for parallel process
*/
-#define PAGE_DATA_NUM (50)
+#define PAGE_FLAG_NUM (20)
+#define PAGE_DATA_NUM (5)
#define WAIT_TIME (60 * 10)
#define PTHREAD_FAIL ((void *)-2)
-#define NUM_BUFFERS (50)
+#define THREAD_REGION (200 * 1024)
struct mmap_cache {
char *mmap_buf;
@@ -985,28 +987,33 @@ struct mmap_cache {
off_t mmap_end_offset;
};
+enum {
+ FLAG_UNUSED,
+ FLAG_READY,
+ FLAG_FILLING
+};
+struct page_flag {
+ mdf_pfn_t pfn;
+ char zero;
+ char ready;
+ short index;
+ struct page_flag *next;
+};
+
struct page_data
{
- mdf_pfn_t pfn;
- int dumpable;
- int zero;
- unsigned int flags;
long size;
unsigned char *buf;
- pthread_mutex_t mutex;
- /*
- * whether the page_data is ready to be consumed
- */
- int ready;
+ int flags;
+ int used;
};
struct thread_args {
int thread_num;
unsigned long len_buf_out;
- mdf_pfn_t start_pfn, end_pfn;
- int page_data_num;
struct cycle *cycle;
struct page_data *page_data_buf;
+ struct page_flag *page_flag_buf;
};
/*
@@ -1295,11 +1302,12 @@ struct DumpInfo {
pthread_t **threads;
struct thread_args *kdump_thread_args;
struct page_data *page_data_buf;
+ struct page_flag **page_flag_buf;
+ sem_t page_flag_buf_sem;
pthread_rwlock_t usemmap_rwlock;
mdf_pfn_t current_pfn;
pthread_mutex_t current_pfn_mutex;
- mdf_pfn_t consumed_pfn;
- pthread_mutex_t consumed_pfn_mutex;
+ pthread_mutex_t page_data_mutex;
pthread_mutex_t filter_mutex;
};
extern struct DumpInfo *info;
--
1.8.3.1
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^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-14 5:42 [PATCH v6] Improve the performance of --num-threads -d 31 Zhou Wenjian
@ 2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
2016-04-14 9:57 ` Minfei Huang
2016-04-15 5:24 ` Atsushi Kumagai
2016-04-15 2:39 ` Minfei Huang
1 sibling, 2 replies; 9+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-04-14 5:56 UTC (permalink / raw)
To: Atsushi Kumagai; +Cc: kexec
Hello Atsushi,
I calculated the memory cost of each thread, and the result is about 50KB.
But I find each thread will take a little more than 100KB actually.
And I set the reserved memory for each thread to 200KB in this version.
I think 200KB is a proper value.
--
Thanks
Zhou
On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
> v6:
> 1. address Atsushi Kumagai's comments about calculating and reserving memory
> v5:
> 1. remove unused variable check_out
> 2. reset num_threads if memory is not enough
> v4:
> 1. fix a bug caused by the logic
> v3:
> 1. remove some unused variables
> 2. fix a bug caused by the wrong logic
> 3. fix a bug caused by optimising
> 4. improve more performance by using Minoru Usui's code
>
> multi-threads implementation will introduce extra cost when handling
> each page. The origin implementation will also do the extra work for
> filtered pages. So there is a big performance degradation in
> --num-threads -d 31.
> The new implementation won't do the extra work for filtered pages any
> more. So the performance of -d 31 is close to that of serial processing.
>
> The new implementation is just like the following:
> * The basic idea is producer producing page and consumer writing page.
> * Each producer have a page_flag_buf list which is used for storing
> page's description.
> * The size of page_flag_buf is little so it won't take too much memory.
> * And all producers will share a page_data_buf array which is
> used for storing page's compressed data.
> * The main thread is the consumer. It will find the next pfn and write
> it into file.
> * The next pfn is smallest pfn in all page_flag_buf.
>
> Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
> Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> ---
> makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
> makedumpfile.h | 38 ++++---
> 2 files changed, 210 insertions(+), 148 deletions(-)
>
> diff --git a/makedumpfile.c b/makedumpfile.c
> index fa0b779..a826321 100644
> --- a/makedumpfile.c
> +++ b/makedumpfile.c
> @@ -3481,9 +3481,8 @@ initial_for_parallel()
> {
> unsigned long len_buf_out;
> unsigned long page_data_buf_size;
> - unsigned long limit_size;
> - int page_data_num;
> - int i;
> + struct page_flag *current;
> + int i, j;
>
> len_buf_out = calculate_len_buf_out(info->page_size);
>
> @@ -3553,20 +3552,7 @@ initial_for_parallel()
> #endif
> }
>
> - /*
> - * get a safe number of page_data
> - */
> - page_data_buf_size = MAX(len_buf_out, info->page_size);
> -
> - limit_size = (get_free_memory_size()
> - - MAP_REGION * info->num_threads) * 0.6;
> -
> - page_data_num = limit_size / page_data_buf_size;
> -
> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> -
> - DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> - info->num_buffers);
> + info->num_buffers = PAGE_DATA_NUM * info->num_threads;
>
> /*
> * allocate memory for page_data
> @@ -3579,6 +3565,7 @@ initial_for_parallel()
> }
> memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
>
> + page_data_buf_size = MAX(len_buf_out, info->page_size);
> for (i = 0; i < info->num_buffers; i++) {
> if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
> MSG("Can't allocate memory for buf of page_data_buf. %s\n",
> @@ -3588,6 +3575,36 @@ initial_for_parallel()
> }
>
> /*
> + * initial page_flag for each thread
> + */
> + if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
> + == NULL) {
> + MSG("Can't allocate memory for page_flag_buf. %s\n",
> + strerror(errno));
> + return FALSE;
> + }
> + memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
> +
> + for (i = 0; i < info->num_threads; i++) {
> + if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
> + MSG("Can't allocate memory for page_flag. %s\n",
> + strerror(errno));
> + return FALSE;
> + }
> + current = info->page_flag_buf[i];
> +
> + for (j = 1; j < PAGE_FLAG_NUM; j++) {
> + if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
> + MSG("Can't allocate memory for page_flag. %s\n",
> + strerror(errno));
> + return FALSE;
> + }
> + current = current->next;
> + }
> + current->next = info->page_flag_buf[i];
> + }
> +
> + /*
> * initial fd_memory for threads
> */
> for (i = 0; i < info->num_threads; i++) {
> @@ -3612,7 +3629,8 @@ initial_for_parallel()
> void
> free_for_parallel()
> {
> - int i;
> + int i, j;
> + struct page_flag *current;
>
> if (info->threads != NULL) {
> for (i = 0; i < info->num_threads; i++) {
> @@ -3655,6 +3673,19 @@ free_for_parallel()
> free(info->page_data_buf);
> }
>
> + if (info->page_flag_buf != NULL) {
> + for (i = 0; i < info->num_threads; i++) {
> + for (j = 0; j < PAGE_FLAG_NUM; j++) {
> + if (info->page_flag_buf[i] != NULL) {
> + current = info->page_flag_buf[i];
> + info->page_flag_buf[i] = current->next;
> + free(current);
> + }
> + }
> + }
> + free(info->page_flag_buf);
> + }
> +
> if (info->parallel_info == NULL)
> return;
>
> @@ -7075,11 +7106,11 @@ void *
> kdump_thread_function_cyclic(void *arg) {
> void *retval = PTHREAD_FAIL;
> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
> - struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> + volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> + volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
> struct cycle *cycle = kdump_thread_args->cycle;
> - int page_data_num = kdump_thread_args->page_data_num;
> - mdf_pfn_t pfn;
> - int index;
> + mdf_pfn_t pfn = cycle->start_pfn;
> + int index = kdump_thread_args->thread_num;
> int buf_ready;
> int dumpable;
> int fd_memory = 0;
> @@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
> kdump_thread_args->thread_num);
> }
>
> - while (1) {
> - /* get next pfn */
> - pthread_mutex_lock(&info->current_pfn_mutex);
> - pfn = info->current_pfn;
> - info->current_pfn++;
> - pthread_mutex_unlock(&info->current_pfn_mutex);
> -
> - if (pfn >= kdump_thread_args->end_pfn)
> - break;
> -
> - index = -1;
> + /*
> + * filtered page won't take anything
> + * unfiltered zero page will only take a page_flag_buf
> + * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
> + */
> + while (pfn < cycle->end_pfn) {
> buf_ready = FALSE;
>
> + pthread_mutex_lock(&info->page_data_mutex);
> + while (page_data_buf[index].used != FALSE) {
> + index = (index + 1) % info->num_buffers;
> + }
> + page_data_buf[index].used = TRUE;
> + pthread_mutex_unlock(&info->page_data_mutex);
> +
> while (buf_ready == FALSE) {
> pthread_testcancel();
> -
> - index = pfn % page_data_num;
> -
> - if (pfn - info->consumed_pfn > info->num_buffers)
> + if (page_flag_buf->ready == FLAG_READY)
> continue;
>
> - if (page_data_buf[index].ready != 0)
> - continue;
> -
> - pthread_mutex_lock(&page_data_buf[index].mutex);
> -
> - if (page_data_buf[index].ready != 0)
> - goto unlock;
> -
> - buf_ready = TRUE;
> + /* get next dumpable pfn */
> + pthread_mutex_lock(&info->current_pfn_mutex);
> + for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
> + dumpable = is_dumpable(
> + info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> + pfn,
> + cycle);
> + if (dumpable)
> + break;
> + }
> + info->current_pfn = pfn + 1;
>
> - page_data_buf[index].pfn = pfn;
> - page_data_buf[index].ready = 1;
> + page_flag_buf->pfn = pfn;
> + page_flag_buf->ready = FLAG_FILLING;
> + pthread_mutex_unlock(&info->current_pfn_mutex);
> + sem_post(&info->page_flag_buf_sem);
>
> - dumpable = is_dumpable(
> - info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> - pfn,
> - cycle);
> - page_data_buf[index].dumpable = dumpable;
> - if (!dumpable)
> - goto unlock;
> + if (pfn >= cycle->end_pfn) {
> + info->current_pfn = cycle->end_pfn;
> + page_data_buf[index].used = FALSE;
> + break;
> + }
>
> if (!read_pfn_parallel(fd_memory, pfn, buf,
> &bitmap_memory_parallel,
> @@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
>
> if ((info->dump_level & DL_EXCLUDE_ZERO)
> && is_zero_page(buf, info->page_size)) {
> - page_data_buf[index].zero = TRUE;
> - goto unlock;
> + page_flag_buf->zero = TRUE;
> + goto next;
> }
>
> - page_data_buf[index].zero = FALSE;
> + page_flag_buf->zero = FALSE;
>
> /*
> * Compress the page data.
> @@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
> page_data_buf[index].size = info->page_size;
> memcpy(page_data_buf[index].buf, buf, info->page_size);
> }
> -unlock:
> - pthread_mutex_unlock(&page_data_buf[index].mutex);
> + page_flag_buf->index = index;
> + buf_ready = TRUE;
> +next:
> + page_flag_buf->ready = FLAG_READY;
> + page_flag_buf = page_flag_buf->next;
>
> }
> }
> -
> retval = NULL;
>
> fail:
> @@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> struct page_desc pd;
> struct timeval tv_start;
> struct timeval last, new;
> - unsigned long long consuming_pfn;
> pthread_t **threads = NULL;
> struct thread_args *kdump_thread_args = NULL;
> void *thread_result;
> - int page_data_num;
> + int page_buf_num;
> struct page_data *page_data_buf = NULL;
> int i;
> int index;
> + int end_count, consuming;
> + mdf_pfn_t current_pfn, temp_pfn;
>
> if (info->flag_elf_dumpfile)
> return FALSE;
> @@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> goto out;
> }
>
> - res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
> - if (res != 0) {
> - ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
> - strerror(res));
> - goto out;
> - }
> -
> res = pthread_mutex_init(&info->filter_mutex, NULL);
> if (res != 0) {
> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
> @@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> end_pfn = cycle->end_pfn;
>
> info->current_pfn = start_pfn;
> - info->consumed_pfn = start_pfn - 1;
>
> threads = info->threads;
> kdump_thread_args = info->kdump_thread_args;
>
> - page_data_num = info->num_buffers;
> + page_buf_num = info->num_buffers;
> page_data_buf = info->page_data_buf;
> + pthread_mutex_init(&info->page_data_mutex, NULL);
> + sem_init(&info->page_flag_buf_sem, 0, 0);
>
> - for (i = 0; i < page_data_num; i++) {
> - /*
> - * producer will use pfn in page_data_buf to decide the
> - * consumed pfn
> - */
> - page_data_buf[i].pfn = start_pfn - 1;
> - page_data_buf[i].ready = 0;
> - res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
> - if (res != 0) {
> - ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
> - strerror(res));
> - goto out;
> - }
> - }
> + for (i = 0; i < page_buf_num; i++)
> + page_data_buf[i].used = FALSE;
>
> for (i = 0; i < info->num_threads; i++) {
> kdump_thread_args[i].thread_num = i;
> kdump_thread_args[i].len_buf_out = len_buf_out;
> - kdump_thread_args[i].start_pfn = start_pfn;
> - kdump_thread_args[i].end_pfn = end_pfn;
> - kdump_thread_args[i].page_data_num = page_data_num;
> kdump_thread_args[i].page_data_buf = page_data_buf;
> + kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
> kdump_thread_args[i].cycle = cycle;
>
> res = pthread_create(threads[i], NULL,
> @@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> }
> }
>
> - consuming_pfn = start_pfn;
> - index = -1;
> + end_count = 0;
> + while (1) {
> + consuming = 0;
>
> - gettimeofday(&last, NULL);
> + /*
> + * The basic idea is producer producing page and consumer writing page.
> + * Each producer have a page_flag_buf list which is used for storing page's description.
> + * The size of page_flag_buf is little so it won't take too much memory.
> + * And all producers will share a page_data_buf array which is used for storing page's compressed data.
> + * The main thread is the consumer. It will find the next pfn and write it into file.
> + * The next pfn is smallest pfn in all page_flag_buf.
> + */
> + sem_wait(&info->page_flag_buf_sem);
> + gettimeofday(&last, NULL);
> + while (1) {
> + current_pfn = end_pfn;
>
> - while (consuming_pfn < end_pfn) {
> - index = consuming_pfn % page_data_num;
> + /*
> + * page_flag_buf is in circular linked list.
> + * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
> + * page_flag_buf list.
> + * consuming is used for recording in which thread the pfn is the smallest.
> + * current_pfn is used for recording the value of pfn when checking the pfn.
> + */
> + for (i = 0; i < info->num_threads; i++) {
> + if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
> + continue;
> + temp_pfn = info->page_flag_buf[i]->pfn;
>
> - gettimeofday(&new, NULL);
> - if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> - ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
> - goto out;
> - }
> + /*
> + * count how many threads have reached the end.
> + */
> + if (temp_pfn >= end_pfn) {
> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
> + end_count++;
> + continue;
> + }
>
> - /*
> - * check pfn first without mutex locked to reduce the time
> - * trying to lock the mutex
> - */
> - if (page_data_buf[index].pfn != consuming_pfn)
> - continue;
> + if (current_pfn < temp_pfn)
> + continue;
>
> - if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
> - continue;
> + consuming = i;
> + current_pfn = temp_pfn;
> + }
>
> - /* check whether the found one is ready to be consumed */
> - if (page_data_buf[index].pfn != consuming_pfn ||
> - page_data_buf[index].ready != 1) {
> - goto unlock;
> + /*
> + * If all the threads have reached the end, we will finish writing.
> + */
> + if (end_count >= info->num_threads)
> + goto finish;
> +
> + /*
> + * If the page_flag_buf is not ready, the pfn recorded may be changed.
> + * So we should recheck.
> + */
> + if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
> + gettimeofday(&new, NULL);
> + if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> + ERRMSG("Can't get data of pfn.\n");
> + goto out;
> + }
> + continue;
> + }
> +
> + if (current_pfn == info->page_flag_buf[consuming]->pfn)
> + break;
> }
>
> if ((num_dumped % per) == 0)
> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
>
> - /* next pfn is found, refresh last here */
> - last = new;
> - consuming_pfn++;
> - info->consumed_pfn++;
> - page_data_buf[index].ready = 0;
> -
> - if (page_data_buf[index].dumpable == FALSE)
> - goto unlock;
> -
> num_dumped++;
>
> - if (page_data_buf[index].zero == TRUE) {
> +
> + if (info->page_flag_buf[consuming]->zero == TRUE) {
> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
> goto out;
> pfn_zero++;
> } else {
> + index = info->page_flag_buf[consuming]->index;
> pd.flags = page_data_buf[index].flags;
> pd.size = page_data_buf[index].size;
> pd.page_flags = 0;
> @@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> */
> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
> goto out;
> -
> + page_data_buf[index].used = FALSE;
> }
> -unlock:
> - pthread_mutex_unlock(&page_data_buf[index].mutex);
> + info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
> + info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
> }
> -
> +finish:
> ret = TRUE;
> /*
> * print [100 %]
> @@ -7463,15 +7509,9 @@ out:
> }
> }
>
> - if (page_data_buf != NULL) {
> - for (i = 0; i < page_data_num; i++) {
> - pthread_mutex_destroy(&page_data_buf[i].mutex);
> - }
> - }
> -
> + sem_destroy(&info->page_flag_buf_sem);
> pthread_rwlock_destroy(&info->usemmap_rwlock);
> pthread_mutex_destroy(&info->filter_mutex);
> - pthread_mutex_destroy(&info->consumed_pfn_mutex);
> pthread_mutex_destroy(&info->current_pfn_mutex);
>
> return ret;
> @@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
> num_dumped++;
> if (!read_pfn(pfn, buf))
> goto out;
> +
> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
>
> /*
> @@ -10201,7 +10242,6 @@ out:
> return free_size;
> }
>
> -
> /*
> * Choose the less value of the three below as the size of cyclic buffer.
> * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
> * free memory for safety.
> */
> limit_size = get_free_memory_size() * 0.6;
> +
> + /*
> + * Recalculate the limit_size according to num_threads.
> + * And reset num_threads if there is not enough memory.
> + */
> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
> +
> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
> + MSG("--num_threads is set to %d.\n", info->num_threads);
> + }
> +
> + limit_size = limit_size - THREAD_REGION * info->num_threads;
> +
> /* Try to keep both 1st and 2nd bitmap at the same time. */
> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
>
> diff --git a/makedumpfile.h b/makedumpfile.h
> index e0b5bbf..322d31b 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -44,6 +44,7 @@
> #include "print_info.h"
> #include "sadump_mod.h"
> #include <pthread.h>
> +#include <semaphore.h>
>
> /*
> * Result of command
> @@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
> * for parallel process
> */
>
> -#define PAGE_DATA_NUM (50)
> +#define PAGE_FLAG_NUM (20)
> +#define PAGE_DATA_NUM (5)
> #define WAIT_TIME (60 * 10)
> #define PTHREAD_FAIL ((void *)-2)
> -#define NUM_BUFFERS (50)
> +#define THREAD_REGION (200 * 1024)
>
> struct mmap_cache {
> char *mmap_buf;
> @@ -985,28 +987,33 @@ struct mmap_cache {
> off_t mmap_end_offset;
> };
>
> +enum {
> + FLAG_UNUSED,
> + FLAG_READY,
> + FLAG_FILLING
> +};
> +struct page_flag {
> + mdf_pfn_t pfn;
> + char zero;
> + char ready;
> + short index;
> + struct page_flag *next;
> +};
> +
> struct page_data
> {
> - mdf_pfn_t pfn;
> - int dumpable;
> - int zero;
> - unsigned int flags;
> long size;
> unsigned char *buf;
> - pthread_mutex_t mutex;
> - /*
> - * whether the page_data is ready to be consumed
> - */
> - int ready;
> + int flags;
> + int used;
> };
>
> struct thread_args {
> int thread_num;
> unsigned long len_buf_out;
> - mdf_pfn_t start_pfn, end_pfn;
> - int page_data_num;
> struct cycle *cycle;
> struct page_data *page_data_buf;
> + struct page_flag *page_flag_buf;
> };
>
> /*
> @@ -1295,11 +1302,12 @@ struct DumpInfo {
> pthread_t **threads;
> struct thread_args *kdump_thread_args;
> struct page_data *page_data_buf;
> + struct page_flag **page_flag_buf;
> + sem_t page_flag_buf_sem;
> pthread_rwlock_t usemmap_rwlock;
> mdf_pfn_t current_pfn;
> pthread_mutex_t current_pfn_mutex;
> - mdf_pfn_t consumed_pfn;
> - pthread_mutex_t consumed_pfn_mutex;
> + pthread_mutex_t page_data_mutex;
> pthread_mutex_t filter_mutex;
> };
> extern struct DumpInfo *info;
>
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
@ 2016-04-14 9:57 ` Minfei Huang
2016-04-15 0:17 ` "Zhou, Wenjian/周文剑"
2016-04-15 5:24 ` Atsushi Kumagai
1 sibling, 1 reply; 9+ messages in thread
From: Minfei Huang @ 2016-04-14 9:57 UTC (permalink / raw)
To: "Zhou, Wenjian/周文剑"; +Cc: Atsushi Kumagai, kexec
On 04/14/16 at 01:56pm, "Zhou, Wenjian/周文剑" wrote:
> Hello Atsushi,
>
> I calculated the memory cost of each thread, and the result is about 50KB.
> But I find each thread will take a little more than 100KB actually.
> And I set the reserved memory for each thread to 200KB in this version.
>
> I think 200KB is a proper value.
Hi, Zhou.
Is there a general formular provided to user to calculate rough reserved
memory, if option num-threads is used?
Thanks
Minfei
>
> --
> Thanks
> Zhou
>
> On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
> >v6:
> > 1. address Atsushi Kumagai's comments about calculating and reserving memory
> >v5:
> > 1. remove unused variable check_out
> > 2. reset num_threads if memory is not enough
> >v4:
> > 1. fix a bug caused by the logic
> >v3:
> > 1. remove some unused variables
> > 2. fix a bug caused by the wrong logic
> > 3. fix a bug caused by optimising
> > 4. improve more performance by using Minoru Usui's code
> >
> >multi-threads implementation will introduce extra cost when handling
> >each page. The origin implementation will also do the extra work for
> >filtered pages. So there is a big performance degradation in
> >--num-threads -d 31.
> >The new implementation won't do the extra work for filtered pages any
> >more. So the performance of -d 31 is close to that of serial processing.
> >
> >The new implementation is just like the following:
> > * The basic idea is producer producing page and consumer writing page.
> > * Each producer have a page_flag_buf list which is used for storing
> > page's description.
> > * The size of page_flag_buf is little so it won't take too much memory.
> > * And all producers will share a page_data_buf array which is
> > used for storing page's compressed data.
> > * The main thread is the consumer. It will find the next pfn and write
> > it into file.
> > * The next pfn is smallest pfn in all page_flag_buf.
> >
> >Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
> >Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> >---
> > makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
> > makedumpfile.h | 38 ++++---
> > 2 files changed, 210 insertions(+), 148 deletions(-)
> >
> >diff --git a/makedumpfile.c b/makedumpfile.c
> >index fa0b779..a826321 100644
> >--- a/makedumpfile.c
> >+++ b/makedumpfile.c
> >@@ -3481,9 +3481,8 @@ initial_for_parallel()
> > {
> > unsigned long len_buf_out;
> > unsigned long page_data_buf_size;
> >- unsigned long limit_size;
> >- int page_data_num;
> >- int i;
> >+ struct page_flag *current;
> >+ int i, j;
> >
> > len_buf_out = calculate_len_buf_out(info->page_size);
> >
> >@@ -3553,20 +3552,7 @@ initial_for_parallel()
> > #endif
> > }
> >
> >- /*
> >- * get a safe number of page_data
> >- */
> >- page_data_buf_size = MAX(len_buf_out, info->page_size);
> >-
> >- limit_size = (get_free_memory_size()
> >- - MAP_REGION * info->num_threads) * 0.6;
> >-
> >- page_data_num = limit_size / page_data_buf_size;
> >-
> >- info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> >-
> >- DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> >- info->num_buffers);
> >+ info->num_buffers = PAGE_DATA_NUM * info->num_threads;
> >
> > /*
> > * allocate memory for page_data
> >@@ -3579,6 +3565,7 @@ initial_for_parallel()
> > }
> > memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
> >
> >+ page_data_buf_size = MAX(len_buf_out, info->page_size);
> > for (i = 0; i < info->num_buffers; i++) {
> > if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
> > MSG("Can't allocate memory for buf of page_data_buf. %s\n",
> >@@ -3588,6 +3575,36 @@ initial_for_parallel()
> > }
> >
> > /*
> >+ * initial page_flag for each thread
> >+ */
> >+ if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
> >+ == NULL) {
> >+ MSG("Can't allocate memory for page_flag_buf. %s\n",
> >+ strerror(errno));
> >+ return FALSE;
> >+ }
> >+ memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
> >+
> >+ for (i = 0; i < info->num_threads; i++) {
> >+ if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
> >+ MSG("Can't allocate memory for page_flag. %s\n",
> >+ strerror(errno));
> >+ return FALSE;
> >+ }
> >+ current = info->page_flag_buf[i];
> >+
> >+ for (j = 1; j < PAGE_FLAG_NUM; j++) {
> >+ if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
> >+ MSG("Can't allocate memory for page_flag. %s\n",
> >+ strerror(errno));
> >+ return FALSE;
> >+ }
> >+ current = current->next;
> >+ }
> >+ current->next = info->page_flag_buf[i];
> >+ }
> >+
> >+ /*
> > * initial fd_memory for threads
> > */
> > for (i = 0; i < info->num_threads; i++) {
> >@@ -3612,7 +3629,8 @@ initial_for_parallel()
> > void
> > free_for_parallel()
> > {
> >- int i;
> >+ int i, j;
> >+ struct page_flag *current;
> >
> > if (info->threads != NULL) {
> > for (i = 0; i < info->num_threads; i++) {
> >@@ -3655,6 +3673,19 @@ free_for_parallel()
> > free(info->page_data_buf);
> > }
> >
> >+ if (info->page_flag_buf != NULL) {
> >+ for (i = 0; i < info->num_threads; i++) {
> >+ for (j = 0; j < PAGE_FLAG_NUM; j++) {
> >+ if (info->page_flag_buf[i] != NULL) {
> >+ current = info->page_flag_buf[i];
> >+ info->page_flag_buf[i] = current->next;
> >+ free(current);
> >+ }
> >+ }
> >+ }
> >+ free(info->page_flag_buf);
> >+ }
> >+
> > if (info->parallel_info == NULL)
> > return;
> >
> >@@ -7075,11 +7106,11 @@ void *
> > kdump_thread_function_cyclic(void *arg) {
> > void *retval = PTHREAD_FAIL;
> > struct thread_args *kdump_thread_args = (struct thread_args *)arg;
> >- struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> >+ volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> >+ volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
> > struct cycle *cycle = kdump_thread_args->cycle;
> >- int page_data_num = kdump_thread_args->page_data_num;
> >- mdf_pfn_t pfn;
> >- int index;
> >+ mdf_pfn_t pfn = cycle->start_pfn;
> >+ int index = kdump_thread_args->thread_num;
> > int buf_ready;
> > int dumpable;
> > int fd_memory = 0;
> >@@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
> > kdump_thread_args->thread_num);
> > }
> >
> >- while (1) {
> >- /* get next pfn */
> >- pthread_mutex_lock(&info->current_pfn_mutex);
> >- pfn = info->current_pfn;
> >- info->current_pfn++;
> >- pthread_mutex_unlock(&info->current_pfn_mutex);
> >-
> >- if (pfn >= kdump_thread_args->end_pfn)
> >- break;
> >-
> >- index = -1;
> >+ /*
> >+ * filtered page won't take anything
> >+ * unfiltered zero page will only take a page_flag_buf
> >+ * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
> >+ */
> >+ while (pfn < cycle->end_pfn) {
> > buf_ready = FALSE;
> >
> >+ pthread_mutex_lock(&info->page_data_mutex);
> >+ while (page_data_buf[index].used != FALSE) {
> >+ index = (index + 1) % info->num_buffers;
> >+ }
> >+ page_data_buf[index].used = TRUE;
> >+ pthread_mutex_unlock(&info->page_data_mutex);
> >+
> > while (buf_ready == FALSE) {
> > pthread_testcancel();
> >-
> >- index = pfn % page_data_num;
> >-
> >- if (pfn - info->consumed_pfn > info->num_buffers)
> >+ if (page_flag_buf->ready == FLAG_READY)
> > continue;
> >
> >- if (page_data_buf[index].ready != 0)
> >- continue;
> >-
> >- pthread_mutex_lock(&page_data_buf[index].mutex);
> >-
> >- if (page_data_buf[index].ready != 0)
> >- goto unlock;
> >-
> >- buf_ready = TRUE;
> >+ /* get next dumpable pfn */
> >+ pthread_mutex_lock(&info->current_pfn_mutex);
> >+ for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
> >+ dumpable = is_dumpable(
> >+ info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> >+ pfn,
> >+ cycle);
> >+ if (dumpable)
> >+ break;
> >+ }
> >+ info->current_pfn = pfn + 1;
> >
> >- page_data_buf[index].pfn = pfn;
> >- page_data_buf[index].ready = 1;
> >+ page_flag_buf->pfn = pfn;
> >+ page_flag_buf->ready = FLAG_FILLING;
> >+ pthread_mutex_unlock(&info->current_pfn_mutex);
> >+ sem_post(&info->page_flag_buf_sem);
> >
> >- dumpable = is_dumpable(
> >- info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> >- pfn,
> >- cycle);
> >- page_data_buf[index].dumpable = dumpable;
> >- if (!dumpable)
> >- goto unlock;
> >+ if (pfn >= cycle->end_pfn) {
> >+ info->current_pfn = cycle->end_pfn;
> >+ page_data_buf[index].used = FALSE;
> >+ break;
> >+ }
> >
> > if (!read_pfn_parallel(fd_memory, pfn, buf,
> > &bitmap_memory_parallel,
> >@@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
> >
> > if ((info->dump_level & DL_EXCLUDE_ZERO)
> > && is_zero_page(buf, info->page_size)) {
> >- page_data_buf[index].zero = TRUE;
> >- goto unlock;
> >+ page_flag_buf->zero = TRUE;
> >+ goto next;
> > }
> >
> >- page_data_buf[index].zero = FALSE;
> >+ page_flag_buf->zero = FALSE;
> >
> > /*
> > * Compress the page data.
> >@@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
> > page_data_buf[index].size = info->page_size;
> > memcpy(page_data_buf[index].buf, buf, info->page_size);
> > }
> >-unlock:
> >- pthread_mutex_unlock(&page_data_buf[index].mutex);
> >+ page_flag_buf->index = index;
> >+ buf_ready = TRUE;
> >+next:
> >+ page_flag_buf->ready = FLAG_READY;
> >+ page_flag_buf = page_flag_buf->next;
> >
> > }
> > }
> >-
> > retval = NULL;
> >
> > fail:
> >@@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > struct page_desc pd;
> > struct timeval tv_start;
> > struct timeval last, new;
> >- unsigned long long consuming_pfn;
> > pthread_t **threads = NULL;
> > struct thread_args *kdump_thread_args = NULL;
> > void *thread_result;
> >- int page_data_num;
> >+ int page_buf_num;
> > struct page_data *page_data_buf = NULL;
> > int i;
> > int index;
> >+ int end_count, consuming;
> >+ mdf_pfn_t current_pfn, temp_pfn;
> >
> > if (info->flag_elf_dumpfile)
> > return FALSE;
> >@@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > goto out;
> > }
> >
> >- res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
> >- if (res != 0) {
> >- ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
> >- strerror(res));
> >- goto out;
> >- }
> >-
> > res = pthread_mutex_init(&info->filter_mutex, NULL);
> > if (res != 0) {
> > ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
> >@@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > end_pfn = cycle->end_pfn;
> >
> > info->current_pfn = start_pfn;
> >- info->consumed_pfn = start_pfn - 1;
> >
> > threads = info->threads;
> > kdump_thread_args = info->kdump_thread_args;
> >
> >- page_data_num = info->num_buffers;
> >+ page_buf_num = info->num_buffers;
> > page_data_buf = info->page_data_buf;
> >+ pthread_mutex_init(&info->page_data_mutex, NULL);
> >+ sem_init(&info->page_flag_buf_sem, 0, 0);
> >
> >- for (i = 0; i < page_data_num; i++) {
> >- /*
> >- * producer will use pfn in page_data_buf to decide the
> >- * consumed pfn
> >- */
> >- page_data_buf[i].pfn = start_pfn - 1;
> >- page_data_buf[i].ready = 0;
> >- res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
> >- if (res != 0) {
> >- ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
> >- strerror(res));
> >- goto out;
> >- }
> >- }
> >+ for (i = 0; i < page_buf_num; i++)
> >+ page_data_buf[i].used = FALSE;
> >
> > for (i = 0; i < info->num_threads; i++) {
> > kdump_thread_args[i].thread_num = i;
> > kdump_thread_args[i].len_buf_out = len_buf_out;
> >- kdump_thread_args[i].start_pfn = start_pfn;
> >- kdump_thread_args[i].end_pfn = end_pfn;
> >- kdump_thread_args[i].page_data_num = page_data_num;
> > kdump_thread_args[i].page_data_buf = page_data_buf;
> >+ kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
> > kdump_thread_args[i].cycle = cycle;
> >
> > res = pthread_create(threads[i], NULL,
> >@@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > }
> > }
> >
> >- consuming_pfn = start_pfn;
> >- index = -1;
> >+ end_count = 0;
> >+ while (1) {
> >+ consuming = 0;
> >
> >- gettimeofday(&last, NULL);
> >+ /*
> >+ * The basic idea is producer producing page and consumer writing page.
> >+ * Each producer have a page_flag_buf list which is used for storing page's description.
> >+ * The size of page_flag_buf is little so it won't take too much memory.
> >+ * And all producers will share a page_data_buf array which is used for storing page's compressed data.
> >+ * The main thread is the consumer. It will find the next pfn and write it into file.
> >+ * The next pfn is smallest pfn in all page_flag_buf.
> >+ */
> >+ sem_wait(&info->page_flag_buf_sem);
> >+ gettimeofday(&last, NULL);
> >+ while (1) {
> >+ current_pfn = end_pfn;
> >
> >- while (consuming_pfn < end_pfn) {
> >- index = consuming_pfn % page_data_num;
> >+ /*
> >+ * page_flag_buf is in circular linked list.
> >+ * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
> >+ * page_flag_buf list.
> >+ * consuming is used for recording in which thread the pfn is the smallest.
> >+ * current_pfn is used for recording the value of pfn when checking the pfn.
> >+ */
> >+ for (i = 0; i < info->num_threads; i++) {
> >+ if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
> >+ continue;
> >+ temp_pfn = info->page_flag_buf[i]->pfn;
> >
> >- gettimeofday(&new, NULL);
> >- if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> >- ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
> >- goto out;
> >- }
> >+ /*
> >+ * count how many threads have reached the end.
> >+ */
> >+ if (temp_pfn >= end_pfn) {
> >+ info->page_flag_buf[i]->ready = FLAG_UNUSED;
> >+ end_count++;
> >+ continue;
> >+ }
> >
> >- /*
> >- * check pfn first without mutex locked to reduce the time
> >- * trying to lock the mutex
> >- */
> >- if (page_data_buf[index].pfn != consuming_pfn)
> >- continue;
> >+ if (current_pfn < temp_pfn)
> >+ continue;
> >
> >- if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
> >- continue;
> >+ consuming = i;
> >+ current_pfn = temp_pfn;
> >+ }
> >
> >- /* check whether the found one is ready to be consumed */
> >- if (page_data_buf[index].pfn != consuming_pfn ||
> >- page_data_buf[index].ready != 1) {
> >- goto unlock;
> >+ /*
> >+ * If all the threads have reached the end, we will finish writing.
> >+ */
> >+ if (end_count >= info->num_threads)
> >+ goto finish;
> >+
> >+ /*
> >+ * If the page_flag_buf is not ready, the pfn recorded may be changed.
> >+ * So we should recheck.
> >+ */
> >+ if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
> >+ gettimeofday(&new, NULL);
> >+ if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> >+ ERRMSG("Can't get data of pfn.\n");
> >+ goto out;
> >+ }
> >+ continue;
> >+ }
> >+
> >+ if (current_pfn == info->page_flag_buf[consuming]->pfn)
> >+ break;
> > }
> >
> > if ((num_dumped % per) == 0)
> > print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
> >
> >- /* next pfn is found, refresh last here */
> >- last = new;
> >- consuming_pfn++;
> >- info->consumed_pfn++;
> >- page_data_buf[index].ready = 0;
> >-
> >- if (page_data_buf[index].dumpable == FALSE)
> >- goto unlock;
> >-
> > num_dumped++;
> >
> >- if (page_data_buf[index].zero == TRUE) {
> >+
> >+ if (info->page_flag_buf[consuming]->zero == TRUE) {
> > if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
> > goto out;
> > pfn_zero++;
> > } else {
> >+ index = info->page_flag_buf[consuming]->index;
> > pd.flags = page_data_buf[index].flags;
> > pd.size = page_data_buf[index].size;
> > pd.page_flags = 0;
> >@@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > */
> > if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
> > goto out;
> >-
> >+ page_data_buf[index].used = FALSE;
> > }
> >-unlock:
> >- pthread_mutex_unlock(&page_data_buf[index].mutex);
> >+ info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
> >+ info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
> > }
> >-
> >+finish:
> > ret = TRUE;
> > /*
> > * print [100 %]
> >@@ -7463,15 +7509,9 @@ out:
> > }
> > }
> >
> >- if (page_data_buf != NULL) {
> >- for (i = 0; i < page_data_num; i++) {
> >- pthread_mutex_destroy(&page_data_buf[i].mutex);
> >- }
> >- }
> >-
> >+ sem_destroy(&info->page_flag_buf_sem);
> > pthread_rwlock_destroy(&info->usemmap_rwlock);
> > pthread_mutex_destroy(&info->filter_mutex);
> >- pthread_mutex_destroy(&info->consumed_pfn_mutex);
> > pthread_mutex_destroy(&info->current_pfn_mutex);
> >
> > return ret;
> >@@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
> > num_dumped++;
> > if (!read_pfn(pfn, buf))
> > goto out;
> >+
> > filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
> >
> > /*
> >@@ -10201,7 +10242,6 @@ out:
> > return free_size;
> > }
> >
> >-
> > /*
> > * Choose the less value of the three below as the size of cyclic buffer.
> > * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
> >@@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
> > * free memory for safety.
> > */
> > limit_size = get_free_memory_size() * 0.6;
> >+
> >+ /*
> >+ * Recalculate the limit_size according to num_threads.
> >+ * And reset num_threads if there is not enough memory.
> >+ */
> >+ if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
> >+ MSG("There isn't enough memory for %d threads.\n", info->num_threads);
> >+
> >+ info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
> >+ MSG("--num_threads is set to %d.\n", info->num_threads);
> >+ }
> >+
> >+ limit_size = limit_size - THREAD_REGION * info->num_threads;
> >+
> > /* Try to keep both 1st and 2nd bitmap at the same time. */
> > bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
> >
> >diff --git a/makedumpfile.h b/makedumpfile.h
> >index e0b5bbf..322d31b 100644
> >--- a/makedumpfile.h
> >+++ b/makedumpfile.h
> >@@ -44,6 +44,7 @@
> > #include "print_info.h"
> > #include "sadump_mod.h"
> > #include <pthread.h>
> >+#include <semaphore.h>
> >
> > /*
> > * Result of command
> >@@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
> > * for parallel process
> > */
> >
> >-#define PAGE_DATA_NUM (50)
> >+#define PAGE_FLAG_NUM (20)
> >+#define PAGE_DATA_NUM (5)
> > #define WAIT_TIME (60 * 10)
> > #define PTHREAD_FAIL ((void *)-2)
> >-#define NUM_BUFFERS (50)
> >+#define THREAD_REGION (200 * 1024)
> >
> > struct mmap_cache {
> > char *mmap_buf;
> >@@ -985,28 +987,33 @@ struct mmap_cache {
> > off_t mmap_end_offset;
> > };
> >
> >+enum {
> >+ FLAG_UNUSED,
> >+ FLAG_READY,
> >+ FLAG_FILLING
> >+};
> >+struct page_flag {
> >+ mdf_pfn_t pfn;
> >+ char zero;
> >+ char ready;
> >+ short index;
> >+ struct page_flag *next;
> >+};
> >+
> > struct page_data
> > {
> >- mdf_pfn_t pfn;
> >- int dumpable;
> >- int zero;
> >- unsigned int flags;
> > long size;
> > unsigned char *buf;
> >- pthread_mutex_t mutex;
> >- /*
> >- * whether the page_data is ready to be consumed
> >- */
> >- int ready;
> >+ int flags;
> >+ int used;
> > };
> >
> > struct thread_args {
> > int thread_num;
> > unsigned long len_buf_out;
> >- mdf_pfn_t start_pfn, end_pfn;
> >- int page_data_num;
> > struct cycle *cycle;
> > struct page_data *page_data_buf;
> >+ struct page_flag *page_flag_buf;
> > };
> >
> > /*
> >@@ -1295,11 +1302,12 @@ struct DumpInfo {
> > pthread_t **threads;
> > struct thread_args *kdump_thread_args;
> > struct page_data *page_data_buf;
> >+ struct page_flag **page_flag_buf;
> >+ sem_t page_flag_buf_sem;
> > pthread_rwlock_t usemmap_rwlock;
> > mdf_pfn_t current_pfn;
> > pthread_mutex_t current_pfn_mutex;
> >- mdf_pfn_t consumed_pfn;
> >- pthread_mutex_t consumed_pfn_mutex;
> >+ pthread_mutex_t page_data_mutex;
> > pthread_mutex_t filter_mutex;
> > };
> > extern struct DumpInfo *info;
> >
>
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-14 9:57 ` Minfei Huang
@ 2016-04-15 0:17 ` "Zhou, Wenjian/周文剑"
2016-04-15 2:09 ` Minfei Huang
0 siblings, 1 reply; 9+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-04-15 0:17 UTC (permalink / raw)
To: Minfei Huang; +Cc: Atsushi Kumagai, kexec
On 04/14/2016 05:57 PM, Minfei Huang wrote:
> On 04/14/16 at 01:56pm, "Zhou, Wenjian/周文剑" wrote:
>> Hello Atsushi,
>>
>> I calculated the memory cost of each thread, and the result is about 50KB.
>> But I find each thread will take a little more than 100KB actually.
>> And I set the reserved memory for each thread to 200KB in this version.
>>
>> I think 200KB is a proper value.
>
> Hi, Zhou.
>
> Is there a general formular provided to user to calculate rough reserved
> memory, if option num-threads is used?
>
Hi Minfei,
That is
max_threads = ((free_memory - 4MB) * 0.6) / 200KB .
And maybe free_memory = reserved_memory - 100MB. I'm not sure about it.
But is it necessary for user to calculate?
If user use too much threads, this patch will reset it to a proper value.
--
Thanks
Zhou
> Thanks
> Minfei
>
>>
>> --
>> Thanks
>> Zhou
>>
>> On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
>>> v6:
>>> 1. address Atsushi Kumagai's comments about calculating and reserving memory
>>> v5:
>>> 1. remove unused variable check_out
>>> 2. reset num_threads if memory is not enough
>>> v4:
>>> 1. fix a bug caused by the logic
>>> v3:
>>> 1. remove some unused variables
>>> 2. fix a bug caused by the wrong logic
>>> 3. fix a bug caused by optimising
>>> 4. improve more performance by using Minoru Usui's code
>>>
>>> multi-threads implementation will introduce extra cost when handling
>>> each page. The origin implementation will also do the extra work for
>>> filtered pages. So there is a big performance degradation in
>>> --num-threads -d 31.
>>> The new implementation won't do the extra work for filtered pages any
>>> more. So the performance of -d 31 is close to that of serial processing.
>>>
>>> The new implementation is just like the following:
>>> * The basic idea is producer producing page and consumer writing page.
>>> * Each producer have a page_flag_buf list which is used for storing
>>> page's description.
>>> * The size of page_flag_buf is little so it won't take too much memory.
>>> * And all producers will share a page_data_buf array which is
>>> used for storing page's compressed data.
>>> * The main thread is the consumer. It will find the next pfn and write
>>> it into file.
>>> * The next pfn is smallest pfn in all page_flag_buf.
>>>
>>> Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
>>> Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
>>> ---
>>> makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
>>> makedumpfile.h | 38 ++++---
>>> 2 files changed, 210 insertions(+), 148 deletions(-)
>>>
>>> diff --git a/makedumpfile.c b/makedumpfile.c
>>> index fa0b779..a826321 100644
>>> --- a/makedumpfile.c
>>> +++ b/makedumpfile.c
>>> @@ -3481,9 +3481,8 @@ initial_for_parallel()
>>> {
>>> unsigned long len_buf_out;
>>> unsigned long page_data_buf_size;
>>> - unsigned long limit_size;
>>> - int page_data_num;
>>> - int i;
>>> + struct page_flag *current;
>>> + int i, j;
>>>
>>> len_buf_out = calculate_len_buf_out(info->page_size);
>>>
>>> @@ -3553,20 +3552,7 @@ initial_for_parallel()
>>> #endif
>>> }
>>>
>>> - /*
>>> - * get a safe number of page_data
>>> - */
>>> - page_data_buf_size = MAX(len_buf_out, info->page_size);
>>> -
>>> - limit_size = (get_free_memory_size()
>>> - - MAP_REGION * info->num_threads) * 0.6;
>>> -
>>> - page_data_num = limit_size / page_data_buf_size;
>>> -
>>> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
>>> -
>>> - DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
>>> - info->num_buffers);
>>> + info->num_buffers = PAGE_DATA_NUM * info->num_threads;
>>>
>>> /*
>>> * allocate memory for page_data
>>> @@ -3579,6 +3565,7 @@ initial_for_parallel()
>>> }
>>> memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
>>>
>>> + page_data_buf_size = MAX(len_buf_out, info->page_size);
>>> for (i = 0; i < info->num_buffers; i++) {
>>> if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
>>> MSG("Can't allocate memory for buf of page_data_buf. %s\n",
>>> @@ -3588,6 +3575,36 @@ initial_for_parallel()
>>> }
>>>
>>> /*
>>> + * initial page_flag for each thread
>>> + */
>>> + if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
>>> + == NULL) {
>>> + MSG("Can't allocate memory for page_flag_buf. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
>>> +
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
>>> + MSG("Can't allocate memory for page_flag. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + current = info->page_flag_buf[i];
>>> +
>>> + for (j = 1; j < PAGE_FLAG_NUM; j++) {
>>> + if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
>>> + MSG("Can't allocate memory for page_flag. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + current = current->next;
>>> + }
>>> + current->next = info->page_flag_buf[i];
>>> + }
>>> +
>>> + /*
>>> * initial fd_memory for threads
>>> */
>>> for (i = 0; i < info->num_threads; i++) {
>>> @@ -3612,7 +3629,8 @@ initial_for_parallel()
>>> void
>>> free_for_parallel()
>>> {
>>> - int i;
>>> + int i, j;
>>> + struct page_flag *current;
>>>
>>> if (info->threads != NULL) {
>>> for (i = 0; i < info->num_threads; i++) {
>>> @@ -3655,6 +3673,19 @@ free_for_parallel()
>>> free(info->page_data_buf);
>>> }
>>>
>>> + if (info->page_flag_buf != NULL) {
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + for (j = 0; j < PAGE_FLAG_NUM; j++) {
>>> + if (info->page_flag_buf[i] != NULL) {
>>> + current = info->page_flag_buf[i];
>>> + info->page_flag_buf[i] = current->next;
>>> + free(current);
>>> + }
>>> + }
>>> + }
>>> + free(info->page_flag_buf);
>>> + }
>>> +
>>> if (info->parallel_info == NULL)
>>> return;
>>>
>>> @@ -7075,11 +7106,11 @@ void *
>>> kdump_thread_function_cyclic(void *arg) {
>>> void *retval = PTHREAD_FAIL;
>>> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
>>> - struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>>> + volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>>> + volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
>>> struct cycle *cycle = kdump_thread_args->cycle;
>>> - int page_data_num = kdump_thread_args->page_data_num;
>>> - mdf_pfn_t pfn;
>>> - int index;
>>> + mdf_pfn_t pfn = cycle->start_pfn;
>>> + int index = kdump_thread_args->thread_num;
>>> int buf_ready;
>>> int dumpable;
>>> int fd_memory = 0;
>>> @@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
>>> kdump_thread_args->thread_num);
>>> }
>>>
>>> - while (1) {
>>> - /* get next pfn */
>>> - pthread_mutex_lock(&info->current_pfn_mutex);
>>> - pfn = info->current_pfn;
>>> - info->current_pfn++;
>>> - pthread_mutex_unlock(&info->current_pfn_mutex);
>>> -
>>> - if (pfn >= kdump_thread_args->end_pfn)
>>> - break;
>>> -
>>> - index = -1;
>>> + /*
>>> + * filtered page won't take anything
>>> + * unfiltered zero page will only take a page_flag_buf
>>> + * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
>>> + */
>>> + while (pfn < cycle->end_pfn) {
>>> buf_ready = FALSE;
>>>
>>> + pthread_mutex_lock(&info->page_data_mutex);
>>> + while (page_data_buf[index].used != FALSE) {
>>> + index = (index + 1) % info->num_buffers;
>>> + }
>>> + page_data_buf[index].used = TRUE;
>>> + pthread_mutex_unlock(&info->page_data_mutex);
>>> +
>>> while (buf_ready == FALSE) {
>>> pthread_testcancel();
>>> -
>>> - index = pfn % page_data_num;
>>> -
>>> - if (pfn - info->consumed_pfn > info->num_buffers)
>>> + if (page_flag_buf->ready == FLAG_READY)
>>> continue;
>>>
>>> - if (page_data_buf[index].ready != 0)
>>> - continue;
>>> -
>>> - pthread_mutex_lock(&page_data_buf[index].mutex);
>>> -
>>> - if (page_data_buf[index].ready != 0)
>>> - goto unlock;
>>> -
>>> - buf_ready = TRUE;
>>> + /* get next dumpable pfn */
>>> + pthread_mutex_lock(&info->current_pfn_mutex);
>>> + for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
>>> + dumpable = is_dumpable(
>>> + info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>>> + pfn,
>>> + cycle);
>>> + if (dumpable)
>>> + break;
>>> + }
>>> + info->current_pfn = pfn + 1;
>>>
>>> - page_data_buf[index].pfn = pfn;
>>> - page_data_buf[index].ready = 1;
>>> + page_flag_buf->pfn = pfn;
>>> + page_flag_buf->ready = FLAG_FILLING;
>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>>> + sem_post(&info->page_flag_buf_sem);
>>>
>>> - dumpable = is_dumpable(
>>> - info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>>> - pfn,
>>> - cycle);
>>> - page_data_buf[index].dumpable = dumpable;
>>> - if (!dumpable)
>>> - goto unlock;
>>> + if (pfn >= cycle->end_pfn) {
>>> + info->current_pfn = cycle->end_pfn;
>>> + page_data_buf[index].used = FALSE;
>>> + break;
>>> + }
>>>
>>> if (!read_pfn_parallel(fd_memory, pfn, buf,
>>> &bitmap_memory_parallel,
>>> @@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
>>>
>>> if ((info->dump_level & DL_EXCLUDE_ZERO)
>>> && is_zero_page(buf, info->page_size)) {
>>> - page_data_buf[index].zero = TRUE;
>>> - goto unlock;
>>> + page_flag_buf->zero = TRUE;
>>> + goto next;
>>> }
>>>
>>> - page_data_buf[index].zero = FALSE;
>>> + page_flag_buf->zero = FALSE;
>>>
>>> /*
>>> * Compress the page data.
>>> @@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
>>> page_data_buf[index].size = info->page_size;
>>> memcpy(page_data_buf[index].buf, buf, info->page_size);
>>> }
>>> -unlock:
>>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>>> + page_flag_buf->index = index;
>>> + buf_ready = TRUE;
>>> +next:
>>> + page_flag_buf->ready = FLAG_READY;
>>> + page_flag_buf = page_flag_buf->next;
>>>
>>> }
>>> }
>>> -
>>> retval = NULL;
>>>
>>> fail:
>>> @@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> struct page_desc pd;
>>> struct timeval tv_start;
>>> struct timeval last, new;
>>> - unsigned long long consuming_pfn;
>>> pthread_t **threads = NULL;
>>> struct thread_args *kdump_thread_args = NULL;
>>> void *thread_result;
>>> - int page_data_num;
>>> + int page_buf_num;
>>> struct page_data *page_data_buf = NULL;
>>> int i;
>>> int index;
>>> + int end_count, consuming;
>>> + mdf_pfn_t current_pfn, temp_pfn;
>>>
>>> if (info->flag_elf_dumpfile)
>>> return FALSE;
>>> @@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> goto out;
>>> }
>>>
>>> - res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
>>> - if (res != 0) {
>>> - ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
>>> - strerror(res));
>>> - goto out;
>>> - }
>>> -
>>> res = pthread_mutex_init(&info->filter_mutex, NULL);
>>> if (res != 0) {
>>> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
>>> @@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> end_pfn = cycle->end_pfn;
>>>
>>> info->current_pfn = start_pfn;
>>> - info->consumed_pfn = start_pfn - 1;
>>>
>>> threads = info->threads;
>>> kdump_thread_args = info->kdump_thread_args;
>>>
>>> - page_data_num = info->num_buffers;
>>> + page_buf_num = info->num_buffers;
>>> page_data_buf = info->page_data_buf;
>>> + pthread_mutex_init(&info->page_data_mutex, NULL);
>>> + sem_init(&info->page_flag_buf_sem, 0, 0);
>>>
>>> - for (i = 0; i < page_data_num; i++) {
>>> - /*
>>> - * producer will use pfn in page_data_buf to decide the
>>> - * consumed pfn
>>> - */
>>> - page_data_buf[i].pfn = start_pfn - 1;
>>> - page_data_buf[i].ready = 0;
>>> - res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
>>> - if (res != 0) {
>>> - ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
>>> - strerror(res));
>>> - goto out;
>>> - }
>>> - }
>>> + for (i = 0; i < page_buf_num; i++)
>>> + page_data_buf[i].used = FALSE;
>>>
>>> for (i = 0; i < info->num_threads; i++) {
>>> kdump_thread_args[i].thread_num = i;
>>> kdump_thread_args[i].len_buf_out = len_buf_out;
>>> - kdump_thread_args[i].start_pfn = start_pfn;
>>> - kdump_thread_args[i].end_pfn = end_pfn;
>>> - kdump_thread_args[i].page_data_num = page_data_num;
>>> kdump_thread_args[i].page_data_buf = page_data_buf;
>>> + kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
>>> kdump_thread_args[i].cycle = cycle;
>>>
>>> res = pthread_create(threads[i], NULL,
>>> @@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> }
>>> }
>>>
>>> - consuming_pfn = start_pfn;
>>> - index = -1;
>>> + end_count = 0;
>>> + while (1) {
>>> + consuming = 0;
>>>
>>> - gettimeofday(&last, NULL);
>>> + /*
>>> + * The basic idea is producer producing page and consumer writing page.
>>> + * Each producer have a page_flag_buf list which is used for storing page's description.
>>> + * The size of page_flag_buf is little so it won't take too much memory.
>>> + * And all producers will share a page_data_buf array which is used for storing page's compressed data.
>>> + * The main thread is the consumer. It will find the next pfn and write it into file.
>>> + * The next pfn is smallest pfn in all page_flag_buf.
>>> + */
>>> + sem_wait(&info->page_flag_buf_sem);
>>> + gettimeofday(&last, NULL);
>>> + while (1) {
>>> + current_pfn = end_pfn;
>>>
>>> - while (consuming_pfn < end_pfn) {
>>> - index = consuming_pfn % page_data_num;
>>> + /*
>>> + * page_flag_buf is in circular linked list.
>>> + * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
>>> + * page_flag_buf list.
>>> + * consuming is used for recording in which thread the pfn is the smallest.
>>> + * current_pfn is used for recording the value of pfn when checking the pfn.
>>> + */
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
>>> + continue;
>>> + temp_pfn = info->page_flag_buf[i]->pfn;
>>>
>>> - gettimeofday(&new, NULL);
>>> - if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>>> - ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
>>> - goto out;
>>> - }
>>> + /*
>>> + * count how many threads have reached the end.
>>> + */
>>> + if (temp_pfn >= end_pfn) {
>>> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
>>> + end_count++;
>>> + continue;
>>> + }
>>>
>>> - /*
>>> - * check pfn first without mutex locked to reduce the time
>>> - * trying to lock the mutex
>>> - */
>>> - if (page_data_buf[index].pfn != consuming_pfn)
>>> - continue;
>>> + if (current_pfn < temp_pfn)
>>> + continue;
>>>
>>> - if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
>>> - continue;
>>> + consuming = i;
>>> + current_pfn = temp_pfn;
>>> + }
>>>
>>> - /* check whether the found one is ready to be consumed */
>>> - if (page_data_buf[index].pfn != consuming_pfn ||
>>> - page_data_buf[index].ready != 1) {
>>> - goto unlock;
>>> + /*
>>> + * If all the threads have reached the end, we will finish writing.
>>> + */
>>> + if (end_count >= info->num_threads)
>>> + goto finish;
>>> +
>>> + /*
>>> + * If the page_flag_buf is not ready, the pfn recorded may be changed.
>>> + * So we should recheck.
>>> + */
>>> + if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
>>> + gettimeofday(&new, NULL);
>>> + if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>>> + ERRMSG("Can't get data of pfn.\n");
>>> + goto out;
>>> + }
>>> + continue;
>>> + }
>>> +
>>> + if (current_pfn == info->page_flag_buf[consuming]->pfn)
>>> + break;
>>> }
>>>
>>> if ((num_dumped % per) == 0)
>>> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
>>>
>>> - /* next pfn is found, refresh last here */
>>> - last = new;
>>> - consuming_pfn++;
>>> - info->consumed_pfn++;
>>> - page_data_buf[index].ready = 0;
>>> -
>>> - if (page_data_buf[index].dumpable == FALSE)
>>> - goto unlock;
>>> -
>>> num_dumped++;
>>>
>>> - if (page_data_buf[index].zero == TRUE) {
>>> +
>>> + if (info->page_flag_buf[consuming]->zero == TRUE) {
>>> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
>>> goto out;
>>> pfn_zero++;
>>> } else {
>>> + index = info->page_flag_buf[consuming]->index;
>>> pd.flags = page_data_buf[index].flags;
>>> pd.size = page_data_buf[index].size;
>>> pd.page_flags = 0;
>>> @@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> */
>>> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
>>> goto out;
>>> -
>>> + page_data_buf[index].used = FALSE;
>>> }
>>> -unlock:
>>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>>> + info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
>>> + info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
>>> }
>>> -
>>> +finish:
>>> ret = TRUE;
>>> /*
>>> * print [100 %]
>>> @@ -7463,15 +7509,9 @@ out:
>>> }
>>> }
>>>
>>> - if (page_data_buf != NULL) {
>>> - for (i = 0; i < page_data_num; i++) {
>>> - pthread_mutex_destroy(&page_data_buf[i].mutex);
>>> - }
>>> - }
>>> -
>>> + sem_destroy(&info->page_flag_buf_sem);
>>> pthread_rwlock_destroy(&info->usemmap_rwlock);
>>> pthread_mutex_destroy(&info->filter_mutex);
>>> - pthread_mutex_destroy(&info->consumed_pfn_mutex);
>>> pthread_mutex_destroy(&info->current_pfn_mutex);
>>>
>>> return ret;
>>> @@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
>>> num_dumped++;
>>> if (!read_pfn(pfn, buf))
>>> goto out;
>>> +
>>> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
>>>
>>> /*
>>> @@ -10201,7 +10242,6 @@ out:
>>> return free_size;
>>> }
>>>
>>> -
>>> /*
>>> * Choose the less value of the three below as the size of cyclic buffer.
>>> * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
>>> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
>>> * free memory for safety.
>>> */
>>> limit_size = get_free_memory_size() * 0.6;
>>> +
>>> + /*
>>> + * Recalculate the limit_size according to num_threads.
>>> + * And reset num_threads if there is not enough memory.
>>> + */
>>> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
>>> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
>>> +
>>> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
>>> + MSG("--num_threads is set to %d.\n", info->num_threads);
>>> + }
>>> +
>>> + limit_size = limit_size - THREAD_REGION * info->num_threads;
>>> +
>>> /* Try to keep both 1st and 2nd bitmap at the same time. */
>>> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
>>>
>>> diff --git a/makedumpfile.h b/makedumpfile.h
>>> index e0b5bbf..322d31b 100644
>>> --- a/makedumpfile.h
>>> +++ b/makedumpfile.h
>>> @@ -44,6 +44,7 @@
>>> #include "print_info.h"
>>> #include "sadump_mod.h"
>>> #include <pthread.h>
>>> +#include <semaphore.h>
>>>
>>> /*
>>> * Result of command
>>> @@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
>>> * for parallel process
>>> */
>>>
>>> -#define PAGE_DATA_NUM (50)
>>> +#define PAGE_FLAG_NUM (20)
>>> +#define PAGE_DATA_NUM (5)
>>> #define WAIT_TIME (60 * 10)
>>> #define PTHREAD_FAIL ((void *)-2)
>>> -#define NUM_BUFFERS (50)
>>> +#define THREAD_REGION (200 * 1024)
>>>
>>> struct mmap_cache {
>>> char *mmap_buf;
>>> @@ -985,28 +987,33 @@ struct mmap_cache {
>>> off_t mmap_end_offset;
>>> };
>>>
>>> +enum {
>>> + FLAG_UNUSED,
>>> + FLAG_READY,
>>> + FLAG_FILLING
>>> +};
>>> +struct page_flag {
>>> + mdf_pfn_t pfn;
>>> + char zero;
>>> + char ready;
>>> + short index;
>>> + struct page_flag *next;
>>> +};
>>> +
>>> struct page_data
>>> {
>>> - mdf_pfn_t pfn;
>>> - int dumpable;
>>> - int zero;
>>> - unsigned int flags;
>>> long size;
>>> unsigned char *buf;
>>> - pthread_mutex_t mutex;
>>> - /*
>>> - * whether the page_data is ready to be consumed
>>> - */
>>> - int ready;
>>> + int flags;
>>> + int used;
>>> };
>>>
>>> struct thread_args {
>>> int thread_num;
>>> unsigned long len_buf_out;
>>> - mdf_pfn_t start_pfn, end_pfn;
>>> - int page_data_num;
>>> struct cycle *cycle;
>>> struct page_data *page_data_buf;
>>> + struct page_flag *page_flag_buf;
>>> };
>>>
>>> /*
>>> @@ -1295,11 +1302,12 @@ struct DumpInfo {
>>> pthread_t **threads;
>>> struct thread_args *kdump_thread_args;
>>> struct page_data *page_data_buf;
>>> + struct page_flag **page_flag_buf;
>>> + sem_t page_flag_buf_sem;
>>> pthread_rwlock_t usemmap_rwlock;
>>> mdf_pfn_t current_pfn;
>>> pthread_mutex_t current_pfn_mutex;
>>> - mdf_pfn_t consumed_pfn;
>>> - pthread_mutex_t consumed_pfn_mutex;
>>> + pthread_mutex_t page_data_mutex;
>>> pthread_mutex_t filter_mutex;
>>> };
>>> extern struct DumpInfo *info;
>>>
>>
>>
>>
>> _______________________________________________
>> kexec mailing list
>> kexec@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-15 0:17 ` "Zhou, Wenjian/周文剑"
@ 2016-04-15 2:09 ` Minfei Huang
0 siblings, 0 replies; 9+ messages in thread
From: Minfei Huang @ 2016-04-15 2:09 UTC (permalink / raw)
To: "Zhou, Wenjian/周文剑"; +Cc: Atsushi Kumagai, kexec
On 04/15/16 at 08:17am, "Zhou, Wenjian/周文剑" wrote:
> On 04/14/2016 05:57 PM, Minfei Huang wrote:
> >On 04/14/16 at 01:56pm, "Zhou, Wenjian/周文剑" wrote:
> >>Hello Atsushi,
> >>
> >>I calculated the memory cost of each thread, and the result is about 50KB.
> >>But I find each thread will take a little more than 100KB actually.
> >>And I set the reserved memory for each thread to 200KB in this version.
> >>
> >>I think 200KB is a proper value.
> >
> >Hi, Zhou.
> >
> >Is there a general formular provided to user to calculate rough reserved
> >memory, if option num-threads is used?
> >
>
> Hi Minfei,
>
> That is
> max_threads = ((free_memory - 4MB) * 0.6) / 200KB .
>
> And maybe free_memory = reserved_memory - 100MB. I'm not sure about it.
>
> But is it necessary for user to calculate?
> If user use too much threads, this patch will reset it to a proper value.
Hi, Zhou.
Glad to hear about it. Thus makedumpfile can works well in limited
memory with inproperly number threads.
Thanks for your efforts.
Thanks
Minfei
>
> --
> Thanks
> Zhou
>
> >Thanks
> >Minfei
> >
> >>
> >>--
> >>Thanks
> >>Zhou
> >>
> >>On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
> >>>v6:
> >>> 1. address Atsushi Kumagai's comments about calculating and reserving memory
> >>>v5:
> >>> 1. remove unused variable check_out
> >>> 2. reset num_threads if memory is not enough
> >>>v4:
> >>> 1. fix a bug caused by the logic
> >>>v3:
> >>> 1. remove some unused variables
> >>> 2. fix a bug caused by the wrong logic
> >>> 3. fix a bug caused by optimising
> >>> 4. improve more performance by using Minoru Usui's code
> >>>
> >>>multi-threads implementation will introduce extra cost when handling
> >>>each page. The origin implementation will also do the extra work for
> >>>filtered pages. So there is a big performance degradation in
> >>>--num-threads -d 31.
> >>>The new implementation won't do the extra work for filtered pages any
> >>>more. So the performance of -d 31 is close to that of serial processing.
> >>>
> >>>The new implementation is just like the following:
> >>> * The basic idea is producer producing page and consumer writing page.
> >>> * Each producer have a page_flag_buf list which is used for storing
> >>> page's description.
> >>> * The size of page_flag_buf is little so it won't take too much memory.
> >>> * And all producers will share a page_data_buf array which is
> >>> used for storing page's compressed data.
> >>> * The main thread is the consumer. It will find the next pfn and write
> >>> it into file.
> >>> * The next pfn is smallest pfn in all page_flag_buf.
> >>>
> >>>Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
> >>>Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> >>>---
> >>> makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
> >>> makedumpfile.h | 38 ++++---
> >>> 2 files changed, 210 insertions(+), 148 deletions(-)
> >>>
> >>>diff --git a/makedumpfile.c b/makedumpfile.c
> >>>index fa0b779..a826321 100644
> >>>--- a/makedumpfile.c
> >>>+++ b/makedumpfile.c
> >>>@@ -3481,9 +3481,8 @@ initial_for_parallel()
> >>> {
> >>> unsigned long len_buf_out;
> >>> unsigned long page_data_buf_size;
> >>>- unsigned long limit_size;
> >>>- int page_data_num;
> >>>- int i;
> >>>+ struct page_flag *current;
> >>>+ int i, j;
> >>>
> >>> len_buf_out = calculate_len_buf_out(info->page_size);
> >>>
> >>>@@ -3553,20 +3552,7 @@ initial_for_parallel()
> >>> #endif
> >>> }
> >>>
> >>>- /*
> >>>- * get a safe number of page_data
> >>>- */
> >>>- page_data_buf_size = MAX(len_buf_out, info->page_size);
> >>>-
> >>>- limit_size = (get_free_memory_size()
> >>>- - MAP_REGION * info->num_threads) * 0.6;
> >>>-
> >>>- page_data_num = limit_size / page_data_buf_size;
> >>>-
> >>>- info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> >>>-
> >>>- DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> >>>- info->num_buffers);
> >>>+ info->num_buffers = PAGE_DATA_NUM * info->num_threads;
> >>>
> >>> /*
> >>> * allocate memory for page_data
> >>>@@ -3579,6 +3565,7 @@ initial_for_parallel()
> >>> }
> >>> memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
> >>>
> >>>+ page_data_buf_size = MAX(len_buf_out, info->page_size);
> >>> for (i = 0; i < info->num_buffers; i++) {
> >>> if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
> >>> MSG("Can't allocate memory for buf of page_data_buf. %s\n",
> >>>@@ -3588,6 +3575,36 @@ initial_for_parallel()
> >>> }
> >>>
> >>> /*
> >>>+ * initial page_flag for each thread
> >>>+ */
> >>>+ if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
> >>>+ == NULL) {
> >>>+ MSG("Can't allocate memory for page_flag_buf. %s\n",
> >>>+ strerror(errno));
> >>>+ return FALSE;
> >>>+ }
> >>>+ memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
> >>>+
> >>>+ for (i = 0; i < info->num_threads; i++) {
> >>>+ if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
> >>>+ MSG("Can't allocate memory for page_flag. %s\n",
> >>>+ strerror(errno));
> >>>+ return FALSE;
> >>>+ }
> >>>+ current = info->page_flag_buf[i];
> >>>+
> >>>+ for (j = 1; j < PAGE_FLAG_NUM; j++) {
> >>>+ if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
> >>>+ MSG("Can't allocate memory for page_flag. %s\n",
> >>>+ strerror(errno));
> >>>+ return FALSE;
> >>>+ }
> >>>+ current = current->next;
> >>>+ }
> >>>+ current->next = info->page_flag_buf[i];
> >>>+ }
> >>>+
> >>>+ /*
> >>> * initial fd_memory for threads
> >>> */
> >>> for (i = 0; i < info->num_threads; i++) {
> >>>@@ -3612,7 +3629,8 @@ initial_for_parallel()
> >>> void
> >>> free_for_parallel()
> >>> {
> >>>- int i;
> >>>+ int i, j;
> >>>+ struct page_flag *current;
> >>>
> >>> if (info->threads != NULL) {
> >>> for (i = 0; i < info->num_threads; i++) {
> >>>@@ -3655,6 +3673,19 @@ free_for_parallel()
> >>> free(info->page_data_buf);
> >>> }
> >>>
> >>>+ if (info->page_flag_buf != NULL) {
> >>>+ for (i = 0; i < info->num_threads; i++) {
> >>>+ for (j = 0; j < PAGE_FLAG_NUM; j++) {
> >>>+ if (info->page_flag_buf[i] != NULL) {
> >>>+ current = info->page_flag_buf[i];
> >>>+ info->page_flag_buf[i] = current->next;
> >>>+ free(current);
> >>>+ }
> >>>+ }
> >>>+ }
> >>>+ free(info->page_flag_buf);
> >>>+ }
> >>>+
> >>> if (info->parallel_info == NULL)
> >>> return;
> >>>
> >>>@@ -7075,11 +7106,11 @@ void *
> >>> kdump_thread_function_cyclic(void *arg) {
> >>> void *retval = PTHREAD_FAIL;
> >>> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
> >>>- struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> >>>+ volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
> >>>+ volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
> >>> struct cycle *cycle = kdump_thread_args->cycle;
> >>>- int page_data_num = kdump_thread_args->page_data_num;
> >>>- mdf_pfn_t pfn;
> >>>- int index;
> >>>+ mdf_pfn_t pfn = cycle->start_pfn;
> >>>+ int index = kdump_thread_args->thread_num;
> >>> int buf_ready;
> >>> int dumpable;
> >>> int fd_memory = 0;
> >>>@@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
> >>> kdump_thread_args->thread_num);
> >>> }
> >>>
> >>>- while (1) {
> >>>- /* get next pfn */
> >>>- pthread_mutex_lock(&info->current_pfn_mutex);
> >>>- pfn = info->current_pfn;
> >>>- info->current_pfn++;
> >>>- pthread_mutex_unlock(&info->current_pfn_mutex);
> >>>-
> >>>- if (pfn >= kdump_thread_args->end_pfn)
> >>>- break;
> >>>-
> >>>- index = -1;
> >>>+ /*
> >>>+ * filtered page won't take anything
> >>>+ * unfiltered zero page will only take a page_flag_buf
> >>>+ * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
> >>>+ */
> >>>+ while (pfn < cycle->end_pfn) {
> >>> buf_ready = FALSE;
> >>>
> >>>+ pthread_mutex_lock(&info->page_data_mutex);
> >>>+ while (page_data_buf[index].used != FALSE) {
> >>>+ index = (index + 1) % info->num_buffers;
> >>>+ }
> >>>+ page_data_buf[index].used = TRUE;
> >>>+ pthread_mutex_unlock(&info->page_data_mutex);
> >>>+
> >>> while (buf_ready == FALSE) {
> >>> pthread_testcancel();
> >>>-
> >>>- index = pfn % page_data_num;
> >>>-
> >>>- if (pfn - info->consumed_pfn > info->num_buffers)
> >>>+ if (page_flag_buf->ready == FLAG_READY)
> >>> continue;
> >>>
> >>>- if (page_data_buf[index].ready != 0)
> >>>- continue;
> >>>-
> >>>- pthread_mutex_lock(&page_data_buf[index].mutex);
> >>>-
> >>>- if (page_data_buf[index].ready != 0)
> >>>- goto unlock;
> >>>-
> >>>- buf_ready = TRUE;
> >>>+ /* get next dumpable pfn */
> >>>+ pthread_mutex_lock(&info->current_pfn_mutex);
> >>>+ for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
> >>>+ dumpable = is_dumpable(
> >>>+ info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> >>>+ pfn,
> >>>+ cycle);
> >>>+ if (dumpable)
> >>>+ break;
> >>>+ }
> >>>+ info->current_pfn = pfn + 1;
> >>>
> >>>- page_data_buf[index].pfn = pfn;
> >>>- page_data_buf[index].ready = 1;
> >>>+ page_flag_buf->pfn = pfn;
> >>>+ page_flag_buf->ready = FLAG_FILLING;
> >>>+ pthread_mutex_unlock(&info->current_pfn_mutex);
> >>>+ sem_post(&info->page_flag_buf_sem);
> >>>
> >>>- dumpable = is_dumpable(
> >>>- info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
> >>>- pfn,
> >>>- cycle);
> >>>- page_data_buf[index].dumpable = dumpable;
> >>>- if (!dumpable)
> >>>- goto unlock;
> >>>+ if (pfn >= cycle->end_pfn) {
> >>>+ info->current_pfn = cycle->end_pfn;
> >>>+ page_data_buf[index].used = FALSE;
> >>>+ break;
> >>>+ }
> >>>
> >>> if (!read_pfn_parallel(fd_memory, pfn, buf,
> >>> &bitmap_memory_parallel,
> >>>@@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
> >>>
> >>> if ((info->dump_level & DL_EXCLUDE_ZERO)
> >>> && is_zero_page(buf, info->page_size)) {
> >>>- page_data_buf[index].zero = TRUE;
> >>>- goto unlock;
> >>>+ page_flag_buf->zero = TRUE;
> >>>+ goto next;
> >>> }
> >>>
> >>>- page_data_buf[index].zero = FALSE;
> >>>+ page_flag_buf->zero = FALSE;
> >>>
> >>> /*
> >>> * Compress the page data.
> >>>@@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
> >>> page_data_buf[index].size = info->page_size;
> >>> memcpy(page_data_buf[index].buf, buf, info->page_size);
> >>> }
> >>>-unlock:
> >>>- pthread_mutex_unlock(&page_data_buf[index].mutex);
> >>>+ page_flag_buf->index = index;
> >>>+ buf_ready = TRUE;
> >>>+next:
> >>>+ page_flag_buf->ready = FLAG_READY;
> >>>+ page_flag_buf = page_flag_buf->next;
> >>>
> >>> }
> >>> }
> >>>-
> >>> retval = NULL;
> >>>
> >>> fail:
> >>>@@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>> struct page_desc pd;
> >>> struct timeval tv_start;
> >>> struct timeval last, new;
> >>>- unsigned long long consuming_pfn;
> >>> pthread_t **threads = NULL;
> >>> struct thread_args *kdump_thread_args = NULL;
> >>> void *thread_result;
> >>>- int page_data_num;
> >>>+ int page_buf_num;
> >>> struct page_data *page_data_buf = NULL;
> >>> int i;
> >>> int index;
> >>>+ int end_count, consuming;
> >>>+ mdf_pfn_t current_pfn, temp_pfn;
> >>>
> >>> if (info->flag_elf_dumpfile)
> >>> return FALSE;
> >>>@@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>> goto out;
> >>> }
> >>>
> >>>- res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
> >>>- if (res != 0) {
> >>>- ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
> >>>- strerror(res));
> >>>- goto out;
> >>>- }
> >>>-
> >>> res = pthread_mutex_init(&info->filter_mutex, NULL);
> >>> if (res != 0) {
> >>> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
> >>>@@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>> end_pfn = cycle->end_pfn;
> >>>
> >>> info->current_pfn = start_pfn;
> >>>- info->consumed_pfn = start_pfn - 1;
> >>>
> >>> threads = info->threads;
> >>> kdump_thread_args = info->kdump_thread_args;
> >>>
> >>>- page_data_num = info->num_buffers;
> >>>+ page_buf_num = info->num_buffers;
> >>> page_data_buf = info->page_data_buf;
> >>>+ pthread_mutex_init(&info->page_data_mutex, NULL);
> >>>+ sem_init(&info->page_flag_buf_sem, 0, 0);
> >>>
> >>>- for (i = 0; i < page_data_num; i++) {
> >>>- /*
> >>>- * producer will use pfn in page_data_buf to decide the
> >>>- * consumed pfn
> >>>- */
> >>>- page_data_buf[i].pfn = start_pfn - 1;
> >>>- page_data_buf[i].ready = 0;
> >>>- res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
> >>>- if (res != 0) {
> >>>- ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
> >>>- strerror(res));
> >>>- goto out;
> >>>- }
> >>>- }
> >>>+ for (i = 0; i < page_buf_num; i++)
> >>>+ page_data_buf[i].used = FALSE;
> >>>
> >>> for (i = 0; i < info->num_threads; i++) {
> >>> kdump_thread_args[i].thread_num = i;
> >>> kdump_thread_args[i].len_buf_out = len_buf_out;
> >>>- kdump_thread_args[i].start_pfn = start_pfn;
> >>>- kdump_thread_args[i].end_pfn = end_pfn;
> >>>- kdump_thread_args[i].page_data_num = page_data_num;
> >>> kdump_thread_args[i].page_data_buf = page_data_buf;
> >>>+ kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
> >>> kdump_thread_args[i].cycle = cycle;
> >>>
> >>> res = pthread_create(threads[i], NULL,
> >>>@@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>> }
> >>> }
> >>>
> >>>- consuming_pfn = start_pfn;
> >>>- index = -1;
> >>>+ end_count = 0;
> >>>+ while (1) {
> >>>+ consuming = 0;
> >>>
> >>>- gettimeofday(&last, NULL);
> >>>+ /*
> >>>+ * The basic idea is producer producing page and consumer writing page.
> >>>+ * Each producer have a page_flag_buf list which is used for storing page's description.
> >>>+ * The size of page_flag_buf is little so it won't take too much memory.
> >>>+ * And all producers will share a page_data_buf array which is used for storing page's compressed data.
> >>>+ * The main thread is the consumer. It will find the next pfn and write it into file.
> >>>+ * The next pfn is smallest pfn in all page_flag_buf.
> >>>+ */
> >>>+ sem_wait(&info->page_flag_buf_sem);
> >>>+ gettimeofday(&last, NULL);
> >>>+ while (1) {
> >>>+ current_pfn = end_pfn;
> >>>
> >>>- while (consuming_pfn < end_pfn) {
> >>>- index = consuming_pfn % page_data_num;
> >>>+ /*
> >>>+ * page_flag_buf is in circular linked list.
> >>>+ * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
> >>>+ * page_flag_buf list.
> >>>+ * consuming is used for recording in which thread the pfn is the smallest.
> >>>+ * current_pfn is used for recording the value of pfn when checking the pfn.
> >>>+ */
> >>>+ for (i = 0; i < info->num_threads; i++) {
> >>>+ if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
> >>>+ continue;
> >>>+ temp_pfn = info->page_flag_buf[i]->pfn;
> >>>
> >>>- gettimeofday(&new, NULL);
> >>>- if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> >>>- ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
> >>>- goto out;
> >>>- }
> >>>+ /*
> >>>+ * count how many threads have reached the end.
> >>>+ */
> >>>+ if (temp_pfn >= end_pfn) {
> >>>+ info->page_flag_buf[i]->ready = FLAG_UNUSED;
> >>>+ end_count++;
> >>>+ continue;
> >>>+ }
> >>>
> >>>- /*
> >>>- * check pfn first without mutex locked to reduce the time
> >>>- * trying to lock the mutex
> >>>- */
> >>>- if (page_data_buf[index].pfn != consuming_pfn)
> >>>- continue;
> >>>+ if (current_pfn < temp_pfn)
> >>>+ continue;
> >>>
> >>>- if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
> >>>- continue;
> >>>+ consuming = i;
> >>>+ current_pfn = temp_pfn;
> >>>+ }
> >>>
> >>>- /* check whether the found one is ready to be consumed */
> >>>- if (page_data_buf[index].pfn != consuming_pfn ||
> >>>- page_data_buf[index].ready != 1) {
> >>>- goto unlock;
> >>>+ /*
> >>>+ * If all the threads have reached the end, we will finish writing.
> >>>+ */
> >>>+ if (end_count >= info->num_threads)
> >>>+ goto finish;
> >>>+
> >>>+ /*
> >>>+ * If the page_flag_buf is not ready, the pfn recorded may be changed.
> >>>+ * So we should recheck.
> >>>+ */
> >>>+ if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
> >>>+ gettimeofday(&new, NULL);
> >>>+ if (new.tv_sec - last.tv_sec > WAIT_TIME) {
> >>>+ ERRMSG("Can't get data of pfn.\n");
> >>>+ goto out;
> >>>+ }
> >>>+ continue;
> >>>+ }
> >>>+
> >>>+ if (current_pfn == info->page_flag_buf[consuming]->pfn)
> >>>+ break;
> >>> }
> >>>
> >>> if ((num_dumped % per) == 0)
> >>> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
> >>>
> >>>- /* next pfn is found, refresh last here */
> >>>- last = new;
> >>>- consuming_pfn++;
> >>>- info->consumed_pfn++;
> >>>- page_data_buf[index].ready = 0;
> >>>-
> >>>- if (page_data_buf[index].dumpable == FALSE)
> >>>- goto unlock;
> >>>-
> >>> num_dumped++;
> >>>
> >>>- if (page_data_buf[index].zero == TRUE) {
> >>>+
> >>>+ if (info->page_flag_buf[consuming]->zero == TRUE) {
> >>> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
> >>> goto out;
> >>> pfn_zero++;
> >>> } else {
> >>>+ index = info->page_flag_buf[consuming]->index;
> >>> pd.flags = page_data_buf[index].flags;
> >>> pd.size = page_data_buf[index].size;
> >>> pd.page_flags = 0;
> >>>@@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> >>> */
> >>> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
> >>> goto out;
> >>>-
> >>>+ page_data_buf[index].used = FALSE;
> >>> }
> >>>-unlock:
> >>>- pthread_mutex_unlock(&page_data_buf[index].mutex);
> >>>+ info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
> >>>+ info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
> >>> }
> >>>-
> >>>+finish:
> >>> ret = TRUE;
> >>> /*
> >>> * print [100 %]
> >>>@@ -7463,15 +7509,9 @@ out:
> >>> }
> >>> }
> >>>
> >>>- if (page_data_buf != NULL) {
> >>>- for (i = 0; i < page_data_num; i++) {
> >>>- pthread_mutex_destroy(&page_data_buf[i].mutex);
> >>>- }
> >>>- }
> >>>-
> >>>+ sem_destroy(&info->page_flag_buf_sem);
> >>> pthread_rwlock_destroy(&info->usemmap_rwlock);
> >>> pthread_mutex_destroy(&info->filter_mutex);
> >>>- pthread_mutex_destroy(&info->consumed_pfn_mutex);
> >>> pthread_mutex_destroy(&info->current_pfn_mutex);
> >>>
> >>> return ret;
> >>>@@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
> >>> num_dumped++;
> >>> if (!read_pfn(pfn, buf))
> >>> goto out;
> >>>+
> >>> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
> >>>
> >>> /*
> >>>@@ -10201,7 +10242,6 @@ out:
> >>> return free_size;
> >>> }
> >>>
> >>>-
> >>> /*
> >>> * Choose the less value of the three below as the size of cyclic buffer.
> >>> * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
> >>>@@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
> >>> * free memory for safety.
> >>> */
> >>> limit_size = get_free_memory_size() * 0.6;
> >>>+
> >>>+ /*
> >>>+ * Recalculate the limit_size according to num_threads.
> >>>+ * And reset num_threads if there is not enough memory.
> >>>+ */
> >>>+ if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
> >>>+ MSG("There isn't enough memory for %d threads.\n", info->num_threads);
> >>>+
> >>>+ info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
> >>>+ MSG("--num_threads is set to %d.\n", info->num_threads);
> >>>+ }
> >>>+
> >>>+ limit_size = limit_size - THREAD_REGION * info->num_threads;
> >>>+
> >>> /* Try to keep both 1st and 2nd bitmap at the same time. */
> >>> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
> >>>
> >>>diff --git a/makedumpfile.h b/makedumpfile.h
> >>>index e0b5bbf..322d31b 100644
> >>>--- a/makedumpfile.h
> >>>+++ b/makedumpfile.h
> >>>@@ -44,6 +44,7 @@
> >>> #include "print_info.h"
> >>> #include "sadump_mod.h"
> >>> #include <pthread.h>
> >>>+#include <semaphore.h>
> >>>
> >>> /*
> >>> * Result of command
> >>>@@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
> >>> * for parallel process
> >>> */
> >>>
> >>>-#define PAGE_DATA_NUM (50)
> >>>+#define PAGE_FLAG_NUM (20)
> >>>+#define PAGE_DATA_NUM (5)
> >>> #define WAIT_TIME (60 * 10)
> >>> #define PTHREAD_FAIL ((void *)-2)
> >>>-#define NUM_BUFFERS (50)
> >>>+#define THREAD_REGION (200 * 1024)
> >>>
> >>> struct mmap_cache {
> >>> char *mmap_buf;
> >>>@@ -985,28 +987,33 @@ struct mmap_cache {
> >>> off_t mmap_end_offset;
> >>> };
> >>>
> >>>+enum {
> >>>+ FLAG_UNUSED,
> >>>+ FLAG_READY,
> >>>+ FLAG_FILLING
> >>>+};
> >>>+struct page_flag {
> >>>+ mdf_pfn_t pfn;
> >>>+ char zero;
> >>>+ char ready;
> >>>+ short index;
> >>>+ struct page_flag *next;
> >>>+};
> >>>+
> >>> struct page_data
> >>> {
> >>>- mdf_pfn_t pfn;
> >>>- int dumpable;
> >>>- int zero;
> >>>- unsigned int flags;
> >>> long size;
> >>> unsigned char *buf;
> >>>- pthread_mutex_t mutex;
> >>>- /*
> >>>- * whether the page_data is ready to be consumed
> >>>- */
> >>>- int ready;
> >>>+ int flags;
> >>>+ int used;
> >>> };
> >>>
> >>> struct thread_args {
> >>> int thread_num;
> >>> unsigned long len_buf_out;
> >>>- mdf_pfn_t start_pfn, end_pfn;
> >>>- int page_data_num;
> >>> struct cycle *cycle;
> >>> struct page_data *page_data_buf;
> >>>+ struct page_flag *page_flag_buf;
> >>> };
> >>>
> >>> /*
> >>>@@ -1295,11 +1302,12 @@ struct DumpInfo {
> >>> pthread_t **threads;
> >>> struct thread_args *kdump_thread_args;
> >>> struct page_data *page_data_buf;
> >>>+ struct page_flag **page_flag_buf;
> >>>+ sem_t page_flag_buf_sem;
> >>> pthread_rwlock_t usemmap_rwlock;
> >>> mdf_pfn_t current_pfn;
> >>> pthread_mutex_t current_pfn_mutex;
> >>>- mdf_pfn_t consumed_pfn;
> >>>- pthread_mutex_t consumed_pfn_mutex;
> >>>+ pthread_mutex_t page_data_mutex;
> >>> pthread_mutex_t filter_mutex;
> >>> };
> >>> extern struct DumpInfo *info;
> >>>
> >>
> >>
> >>
> >>_______________________________________________
> >>kexec mailing list
> >>kexec@lists.infradead.org
> >>http://lists.infradead.org/mailman/listinfo/kexec
>
>
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-15 2:39 ` Minfei Huang
@ 2016-04-15 2:38 ` "Zhou, Wenjian/周文剑"
0 siblings, 0 replies; 9+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-04-15 2:38 UTC (permalink / raw)
To: Minfei Huang; +Cc: kexec
On 04/15/2016 10:39 AM, Minfei Huang wrote:
> On 04/14/16 at 01:42pm, Zhou Wenjian wrote:
>> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
>> * free memory for safety.
>> */
>> limit_size = get_free_memory_size() * 0.6;
>> +
>> + /*
>> + * Recalculate the limit_size according to num_threads.
>> + * And reset num_threads if there is not enough memory.
>> + */
>> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
>> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
>> +
>> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
>
> Hi, Zhou.
>
> Since both limit_size and maximum_size are unsigned long long,
> comparison is necessary for the if branch. Thus the micro MAX can be
> removed as well.
>
Oh, I made a stupid mistake.
Thanks for pointing it out.
--
Thanks
Zhou
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-14 5:42 [PATCH v6] Improve the performance of --num-threads -d 31 Zhou Wenjian
2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
@ 2016-04-15 2:39 ` Minfei Huang
2016-04-15 2:38 ` "Zhou, Wenjian/周文剑"
1 sibling, 1 reply; 9+ messages in thread
From: Minfei Huang @ 2016-04-15 2:39 UTC (permalink / raw)
To: Zhou Wenjian; +Cc: kexec
On 04/14/16 at 01:42pm, Zhou Wenjian wrote:
> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
> * free memory for safety.
> */
> limit_size = get_free_memory_size() * 0.6;
> +
> + /*
> + * Recalculate the limit_size according to num_threads.
> + * And reset num_threads if there is not enough memory.
> + */
> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
> +
> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
Hi, Zhou.
Since both limit_size and maximum_size are unsigned long long,
comparison is necessary for the if branch. Thus the micro MAX can be
removed as well.
Thanks
Minfei
_______________________________________________
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 9+ messages in thread
* RE: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
2016-04-14 9:57 ` Minfei Huang
@ 2016-04-15 5:24 ` Atsushi Kumagai
2016-04-15 10:09 ` "Zhou, Wenjian/周文剑"
1 sibling, 1 reply; 9+ messages in thread
From: Atsushi Kumagai @ 2016-04-15 5:24 UTC (permalink / raw)
To: "Zhou, Wenjian/周文剑"
Cc: kexec@lists.infradead.org
>Hello Atsushi,
>
>I calculated the memory cost of each thread, and the result is about 50KB.
>But I find each thread will take a little more than 100KB actually.
>And I set the reserved memory for each thread to 200KB in this version.
>
>I think 200KB is a proper value.
My test result was similar to yours, so the estimate seems basically right.
Of course, It's better to break down the memory cost...
Anyway, I have a comment for this version.
You changed the way to calculate the number of page_data_buf in v6,
doesn't it affect the performance ? and please explain the reason when
you change the code.
P.S. I'll comment for v7 later.
Thanks,
Atsushi Kumagai
>--
>Thanks
>Zhou
>
>On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
>> v6:
>> 1. address Atsushi Kumagai's comments about calculating and reserving memory
>> v5:
>> 1. remove unused variable check_out
>> 2. reset num_threads if memory is not enough
>> v4:
>> 1. fix a bug caused by the logic
>> v3:
>> 1. remove some unused variables
>> 2. fix a bug caused by the wrong logic
>> 3. fix a bug caused by optimising
>> 4. improve more performance by using Minoru Usui's code
>>
>> multi-threads implementation will introduce extra cost when handling
>> each page. The origin implementation will also do the extra work for
>> filtered pages. So there is a big performance degradation in
>> --num-threads -d 31.
>> The new implementation won't do the extra work for filtered pages any
>> more. So the performance of -d 31 is close to that of serial processing.
>>
>> The new implementation is just like the following:
>> * The basic idea is producer producing page and consumer writing page.
>> * Each producer have a page_flag_buf list which is used for storing
>> page's description.
>> * The size of page_flag_buf is little so it won't take too much memory.
>> * And all producers will share a page_data_buf array which is
>> used for storing page's compressed data.
>> * The main thread is the consumer. It will find the next pfn and write
>> it into file.
>> * The next pfn is smallest pfn in all page_flag_buf.
>>
>> Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
>> Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
>> ---
>> makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
>> makedumpfile.h | 38 ++++---
>> 2 files changed, 210 insertions(+), 148 deletions(-)
>>
>> diff --git a/makedumpfile.c b/makedumpfile.c
>> index fa0b779..a826321 100644
>> --- a/makedumpfile.c
>> +++ b/makedumpfile.c
>> @@ -3481,9 +3481,8 @@ initial_for_parallel()
>> {
>> unsigned long len_buf_out;
>> unsigned long page_data_buf_size;
>> - unsigned long limit_size;
>> - int page_data_num;
>> - int i;
>> + struct page_flag *current;
>> + int i, j;
>>
>> len_buf_out = calculate_len_buf_out(info->page_size);
>>
>> @@ -3553,20 +3552,7 @@ initial_for_parallel()
>> #endif
>> }
>>
>> - /*
>> - * get a safe number of page_data
>> - */
>> - page_data_buf_size = MAX(len_buf_out, info->page_size);
>> -
>> - limit_size = (get_free_memory_size()
>> - - MAP_REGION * info->num_threads) * 0.6;
>> -
>> - page_data_num = limit_size / page_data_buf_size;
>> -
>> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
>> -
>> - DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
>> - info->num_buffers);
>> + info->num_buffers = PAGE_DATA_NUM * info->num_threads;
>>
>> /*
>> * allocate memory for page_data
>> @@ -3579,6 +3565,7 @@ initial_for_parallel()
>> }
>> memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
>>
>> + page_data_buf_size = MAX(len_buf_out, info->page_size);
>> for (i = 0; i < info->num_buffers; i++) {
>> if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
>> MSG("Can't allocate memory for buf of page_data_buf. %s\n",
>> @@ -3588,6 +3575,36 @@ initial_for_parallel()
>> }
>>
>> /*
>> + * initial page_flag for each thread
>> + */
>> + if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
>> + == NULL) {
>> + MSG("Can't allocate memory for page_flag_buf. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
>> +
>> + for (i = 0; i < info->num_threads; i++) {
>> + if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
>> + MSG("Can't allocate memory for page_flag. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + current = info->page_flag_buf[i];
>> +
>> + for (j = 1; j < PAGE_FLAG_NUM; j++) {
>> + if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
>> + MSG("Can't allocate memory for page_flag. %s\n",
>> + strerror(errno));
>> + return FALSE;
>> + }
>> + current = current->next;
>> + }
>> + current->next = info->page_flag_buf[i];
>> + }
>> +
>> + /*
>> * initial fd_memory for threads
>> */
>> for (i = 0; i < info->num_threads; i++) {
>> @@ -3612,7 +3629,8 @@ initial_for_parallel()
>> void
>> free_for_parallel()
>> {
>> - int i;
>> + int i, j;
>> + struct page_flag *current;
>>
>> if (info->threads != NULL) {
>> for (i = 0; i < info->num_threads; i++) {
>> @@ -3655,6 +3673,19 @@ free_for_parallel()
>> free(info->page_data_buf);
>> }
>>
>> + if (info->page_flag_buf != NULL) {
>> + for (i = 0; i < info->num_threads; i++) {
>> + for (j = 0; j < PAGE_FLAG_NUM; j++) {
>> + if (info->page_flag_buf[i] != NULL) {
>> + current = info->page_flag_buf[i];
>> + info->page_flag_buf[i] = current->next;
>> + free(current);
>> + }
>> + }
>> + }
>> + free(info->page_flag_buf);
>> + }
>> +
>> if (info->parallel_info == NULL)
>> return;
>>
>> @@ -7075,11 +7106,11 @@ void *
>> kdump_thread_function_cyclic(void *arg) {
>> void *retval = PTHREAD_FAIL;
>> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
>> - struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>> + volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>> + volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
>> struct cycle *cycle = kdump_thread_args->cycle;
>> - int page_data_num = kdump_thread_args->page_data_num;
>> - mdf_pfn_t pfn;
>> - int index;
>> + mdf_pfn_t pfn = cycle->start_pfn;
>> + int index = kdump_thread_args->thread_num;
>> int buf_ready;
>> int dumpable;
>> int fd_memory = 0;
>> @@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
>> kdump_thread_args->thread_num);
>> }
>>
>> - while (1) {
>> - /* get next pfn */
>> - pthread_mutex_lock(&info->current_pfn_mutex);
>> - pfn = info->current_pfn;
>> - info->current_pfn++;
>> - pthread_mutex_unlock(&info->current_pfn_mutex);
>> -
>> - if (pfn >= kdump_thread_args->end_pfn)
>> - break;
>> -
>> - index = -1;
>> + /*
>> + * filtered page won't take anything
>> + * unfiltered zero page will only take a page_flag_buf
>> + * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
>> + */
>> + while (pfn < cycle->end_pfn) {
>> buf_ready = FALSE;
>>
>> + pthread_mutex_lock(&info->page_data_mutex);
>> + while (page_data_buf[index].used != FALSE) {
>> + index = (index + 1) % info->num_buffers;
>> + }
>> + page_data_buf[index].used = TRUE;
>> + pthread_mutex_unlock(&info->page_data_mutex);
>> +
>> while (buf_ready == FALSE) {
>> pthread_testcancel();
>> -
>> - index = pfn % page_data_num;
>> -
>> - if (pfn - info->consumed_pfn > info->num_buffers)
>> + if (page_flag_buf->ready == FLAG_READY)
>> continue;
>>
>> - if (page_data_buf[index].ready != 0)
>> - continue;
>> -
>> - pthread_mutex_lock(&page_data_buf[index].mutex);
>> -
>> - if (page_data_buf[index].ready != 0)
>> - goto unlock;
>> -
>> - buf_ready = TRUE;
>> + /* get next dumpable pfn */
>> + pthread_mutex_lock(&info->current_pfn_mutex);
>> + for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
>> + dumpable = is_dumpable(
>> + info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>> + pfn,
>> + cycle);
>> + if (dumpable)
>> + break;
>> + }
>> + info->current_pfn = pfn + 1;
>>
>> - page_data_buf[index].pfn = pfn;
>> - page_data_buf[index].ready = 1;
>> + page_flag_buf->pfn = pfn;
>> + page_flag_buf->ready = FLAG_FILLING;
>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>> + sem_post(&info->page_flag_buf_sem);
>>
>> - dumpable = is_dumpable(
>> - info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>> - pfn,
>> - cycle);
>> - page_data_buf[index].dumpable = dumpable;
>> - if (!dumpable)
>> - goto unlock;
>> + if (pfn >= cycle->end_pfn) {
>> + info->current_pfn = cycle->end_pfn;
>> + page_data_buf[index].used = FALSE;
>> + break;
>> + }
>>
>> if (!read_pfn_parallel(fd_memory, pfn, buf,
>> &bitmap_memory_parallel,
>> @@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
>>
>> if ((info->dump_level & DL_EXCLUDE_ZERO)
>> && is_zero_page(buf, info->page_size)) {
>> - page_data_buf[index].zero = TRUE;
>> - goto unlock;
>> + page_flag_buf->zero = TRUE;
>> + goto next;
>> }
>>
>> - page_data_buf[index].zero = FALSE;
>> + page_flag_buf->zero = FALSE;
>>
>> /*
>> * Compress the page data.
>> @@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
>> page_data_buf[index].size = info->page_size;
>> memcpy(page_data_buf[index].buf, buf, info->page_size);
>> }
>> -unlock:
>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>> + page_flag_buf->index = index;
>> + buf_ready = TRUE;
>> +next:
>> + page_flag_buf->ready = FLAG_READY;
>> + page_flag_buf = page_flag_buf->next;
>>
>> }
>> }
>> -
>> retval = NULL;
>>
>> fail:
>> @@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> struct page_desc pd;
>> struct timeval tv_start;
>> struct timeval last, new;
>> - unsigned long long consuming_pfn;
>> pthread_t **threads = NULL;
>> struct thread_args *kdump_thread_args = NULL;
>> void *thread_result;
>> - int page_data_num;
>> + int page_buf_num;
>> struct page_data *page_data_buf = NULL;
>> int i;
>> int index;
>> + int end_count, consuming;
>> + mdf_pfn_t current_pfn, temp_pfn;
>>
>> if (info->flag_elf_dumpfile)
>> return FALSE;
>> @@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> goto out;
>> }
>>
>> - res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
>> - if (res != 0) {
>> - ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
>> - strerror(res));
>> - goto out;
>> - }
>> -
>> res = pthread_mutex_init(&info->filter_mutex, NULL);
>> if (res != 0) {
>> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
>> @@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> end_pfn = cycle->end_pfn;
>>
>> info->current_pfn = start_pfn;
>> - info->consumed_pfn = start_pfn - 1;
>>
>> threads = info->threads;
>> kdump_thread_args = info->kdump_thread_args;
>>
>> - page_data_num = info->num_buffers;
>> + page_buf_num = info->num_buffers;
>> page_data_buf = info->page_data_buf;
>> + pthread_mutex_init(&info->page_data_mutex, NULL);
>> + sem_init(&info->page_flag_buf_sem, 0, 0);
>>
>> - for (i = 0; i < page_data_num; i++) {
>> - /*
>> - * producer will use pfn in page_data_buf to decide the
>> - * consumed pfn
>> - */
>> - page_data_buf[i].pfn = start_pfn - 1;
>> - page_data_buf[i].ready = 0;
>> - res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
>> - if (res != 0) {
>> - ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
>> - strerror(res));
>> - goto out;
>> - }
>> - }
>> + for (i = 0; i < page_buf_num; i++)
>> + page_data_buf[i].used = FALSE;
>>
>> for (i = 0; i < info->num_threads; i++) {
>> kdump_thread_args[i].thread_num = i;
>> kdump_thread_args[i].len_buf_out = len_buf_out;
>> - kdump_thread_args[i].start_pfn = start_pfn;
>> - kdump_thread_args[i].end_pfn = end_pfn;
>> - kdump_thread_args[i].page_data_num = page_data_num;
>> kdump_thread_args[i].page_data_buf = page_data_buf;
>> + kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
>> kdump_thread_args[i].cycle = cycle;
>>
>> res = pthread_create(threads[i], NULL,
>> @@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> }
>> }
>>
>> - consuming_pfn = start_pfn;
>> - index = -1;
>> + end_count = 0;
>> + while (1) {
>> + consuming = 0;
>>
>> - gettimeofday(&last, NULL);
>> + /*
>> + * The basic idea is producer producing page and consumer writing page.
>> + * Each producer have a page_flag_buf list which is used for storing page's description.
>> + * The size of page_flag_buf is little so it won't take too much memory.
>> + * And all producers will share a page_data_buf array which is used for storing page's compressed data.
>> + * The main thread is the consumer. It will find the next pfn and write it into file.
>> + * The next pfn is smallest pfn in all page_flag_buf.
>> + */
>> + sem_wait(&info->page_flag_buf_sem);
>> + gettimeofday(&last, NULL);
>> + while (1) {
>> + current_pfn = end_pfn;
>>
>> - while (consuming_pfn < end_pfn) {
>> - index = consuming_pfn % page_data_num;
>> + /*
>> + * page_flag_buf is in circular linked list.
>> + * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
>> + * page_flag_buf list.
>> + * consuming is used for recording in which thread the pfn is the smallest.
>> + * current_pfn is used for recording the value of pfn when checking the pfn.
>> + */
>> + for (i = 0; i < info->num_threads; i++) {
>> + if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
>> + continue;
>> + temp_pfn = info->page_flag_buf[i]->pfn;
>>
>> - gettimeofday(&new, NULL);
>> - if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>> - ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
>> - goto out;
>> - }
>> + /*
>> + * count how many threads have reached the end.
>> + */
>> + if (temp_pfn >= end_pfn) {
>> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
>> + end_count++;
>> + continue;
>> + }
>>
>> - /*
>> - * check pfn first without mutex locked to reduce the time
>> - * trying to lock the mutex
>> - */
>> - if (page_data_buf[index].pfn != consuming_pfn)
>> - continue;
>> + if (current_pfn < temp_pfn)
>> + continue;
>>
>> - if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
>> - continue;
>> + consuming = i;
>> + current_pfn = temp_pfn;
>> + }
>>
>> - /* check whether the found one is ready to be consumed */
>> - if (page_data_buf[index].pfn != consuming_pfn ||
>> - page_data_buf[index].ready != 1) {
>> - goto unlock;
>> + /*
>> + * If all the threads have reached the end, we will finish writing.
>> + */
>> + if (end_count >= info->num_threads)
>> + goto finish;
>> +
>> + /*
>> + * If the page_flag_buf is not ready, the pfn recorded may be changed.
>> + * So we should recheck.
>> + */
>> + if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
>> + gettimeofday(&new, NULL);
>> + if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>> + ERRMSG("Can't get data of pfn.\n");
>> + goto out;
>> + }
>> + continue;
>> + }
>> +
>> + if (current_pfn == info->page_flag_buf[consuming]->pfn)
>> + break;
>> }
>>
>> if ((num_dumped % per) == 0)
>> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
>>
>> - /* next pfn is found, refresh last here */
>> - last = new;
>> - consuming_pfn++;
>> - info->consumed_pfn++;
>> - page_data_buf[index].ready = 0;
>> -
>> - if (page_data_buf[index].dumpable == FALSE)
>> - goto unlock;
>> -
>> num_dumped++;
>>
>> - if (page_data_buf[index].zero == TRUE) {
>> +
>> + if (info->page_flag_buf[consuming]->zero == TRUE) {
>> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
>> goto out;
>> pfn_zero++;
>> } else {
>> + index = info->page_flag_buf[consuming]->index;
>> pd.flags = page_data_buf[index].flags;
>> pd.size = page_data_buf[index].size;
>> pd.page_flags = 0;
>> @@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>> */
>> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
>> goto out;
>> -
>> + page_data_buf[index].used = FALSE;
>> }
>> -unlock:
>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>> + info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
>> + info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
>> }
>> -
>> +finish:
>> ret = TRUE;
>> /*
>> * print [100 %]
>> @@ -7463,15 +7509,9 @@ out:
>> }
>> }
>>
>> - if (page_data_buf != NULL) {
>> - for (i = 0; i < page_data_num; i++) {
>> - pthread_mutex_destroy(&page_data_buf[i].mutex);
>> - }
>> - }
>> -
>> + sem_destroy(&info->page_flag_buf_sem);
>> pthread_rwlock_destroy(&info->usemmap_rwlock);
>> pthread_mutex_destroy(&info->filter_mutex);
>> - pthread_mutex_destroy(&info->consumed_pfn_mutex);
>> pthread_mutex_destroy(&info->current_pfn_mutex);
>>
>> return ret;
>> @@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
>> num_dumped++;
>> if (!read_pfn(pfn, buf))
>> goto out;
>> +
>> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
>>
>> /*
>> @@ -10201,7 +10242,6 @@ out:
>> return free_size;
>> }
>>
>> -
>> /*
>> * Choose the less value of the three below as the size of cyclic buffer.
>> * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
>> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
>> * free memory for safety.
>> */
>> limit_size = get_free_memory_size() * 0.6;
>> +
>> + /*
>> + * Recalculate the limit_size according to num_threads.
>> + * And reset num_threads if there is not enough memory.
>> + */
>> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
>> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
>> +
>> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
>> + MSG("--num_threads is set to %d.\n", info->num_threads);
>> + }
>> +
>> + limit_size = limit_size - THREAD_REGION * info->num_threads;
>> +
>> /* Try to keep both 1st and 2nd bitmap at the same time. */
>> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
>>
>> diff --git a/makedumpfile.h b/makedumpfile.h
>> index e0b5bbf..322d31b 100644
>> --- a/makedumpfile.h
>> +++ b/makedumpfile.h
>> @@ -44,6 +44,7 @@
>> #include "print_info.h"
>> #include "sadump_mod.h"
>> #include <pthread.h>
>> +#include <semaphore.h>
>>
>> /*
>> * Result of command
>> @@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
>> * for parallel process
>> */
>>
>> -#define PAGE_DATA_NUM (50)
>> +#define PAGE_FLAG_NUM (20)
>> +#define PAGE_DATA_NUM (5)
>> #define WAIT_TIME (60 * 10)
>> #define PTHREAD_FAIL ((void *)-2)
>> -#define NUM_BUFFERS (50)
>> +#define THREAD_REGION (200 * 1024)
>>
>> struct mmap_cache {
>> char *mmap_buf;
>> @@ -985,28 +987,33 @@ struct mmap_cache {
>> off_t mmap_end_offset;
>> };
>>
>> +enum {
>> + FLAG_UNUSED,
>> + FLAG_READY,
>> + FLAG_FILLING
>> +};
>> +struct page_flag {
>> + mdf_pfn_t pfn;
>> + char zero;
>> + char ready;
>> + short index;
>> + struct page_flag *next;
>> +};
>> +
>> struct page_data
>> {
>> - mdf_pfn_t pfn;
>> - int dumpable;
>> - int zero;
>> - unsigned int flags;
>> long size;
>> unsigned char *buf;
>> - pthread_mutex_t mutex;
>> - /*
>> - * whether the page_data is ready to be consumed
>> - */
>> - int ready;
>> + int flags;
>> + int used;
>> };
>>
>> struct thread_args {
>> int thread_num;
>> unsigned long len_buf_out;
>> - mdf_pfn_t start_pfn, end_pfn;
>> - int page_data_num;
>> struct cycle *cycle;
>> struct page_data *page_data_buf;
>> + struct page_flag *page_flag_buf;
>> };
>>
>> /*
>> @@ -1295,11 +1302,12 @@ struct DumpInfo {
>> pthread_t **threads;
>> struct thread_args *kdump_thread_args;
>> struct page_data *page_data_buf;
>> + struct page_flag **page_flag_buf;
>> + sem_t page_flag_buf_sem;
>> pthread_rwlock_t usemmap_rwlock;
>> mdf_pfn_t current_pfn;
>> pthread_mutex_t current_pfn_mutex;
>> - mdf_pfn_t consumed_pfn;
>> - pthread_mutex_t consumed_pfn_mutex;
>> + pthread_mutex_t page_data_mutex;
>> pthread_mutex_t filter_mutex;
>> };
>> extern struct DumpInfo *info;
>>
>
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kexec@lists.infradead.org
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v6] Improve the performance of --num-threads -d 31
2016-04-15 5:24 ` Atsushi Kumagai
@ 2016-04-15 10:09 ` "Zhou, Wenjian/周文剑"
0 siblings, 0 replies; 9+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-04-15 10:09 UTC (permalink / raw)
To: Atsushi Kumagai; +Cc: kexec@lists.infradead.org
On 04/15/2016 01:24 PM, Atsushi Kumagai wrote:
>> Hello Atsushi,
>>
>> I calculated the memory cost of each thread, and the result is about 50KB.
>> But I find each thread will take a little more than 100KB actually.
>> And I set the reserved memory for each thread to 200KB in this version.
>>
>> I think 200KB is a proper value.
>
> My test result was similar to yours, so the estimate seems basically right.
> Of course, It's better to break down the memory cost...
>
> Anyway, I have a comment for this version.
>
> You changed the way to calculate the number of page_data_buf in v6,
> doesn't it affect the performance ? and please explain the reason when
> you change the code.
>
I think it won't affect too much. But it needs to be tested.
The reason is to simplify the logic.
In the original implementation, NUM_BUFFERS is used to calculate both page_flag_buf
and page_data_buf's number.
And the page_data_buf's number is also associated with the code "3 * info->num_threads".
So I think it is not easy to read.
In this version, the number of page_data_buf will be only calculated by
"PAGE_DATA_NUM * info->num_threads".
I think it is better if it won't affect too much.
But I won't insist, for the original is also acceptable.
--
Thanks
Zhou
> P.S. I'll comment for v7 later.
>
>
> Thanks,
> Atsushi Kumagai
>
>> --
>> Thanks
>> Zhou
>>
>> On 04/14/2016 01:42 PM, Zhou Wenjian wrote:
>>> v6:
>>> 1. address Atsushi Kumagai's comments about calculating and reserving memory
>>> v5:
>>> 1. remove unused variable check_out
>>> 2. reset num_threads if memory is not enough
>>> v4:
>>> 1. fix a bug caused by the logic
>>> v3:
>>> 1. remove some unused variables
>>> 2. fix a bug caused by the wrong logic
>>> 3. fix a bug caused by optimising
>>> 4. improve more performance by using Minoru Usui's code
>>>
>>> multi-threads implementation will introduce extra cost when handling
>>> each page. The origin implementation will also do the extra work for
>>> filtered pages. So there is a big performance degradation in
>>> --num-threads -d 31.
>>> The new implementation won't do the extra work for filtered pages any
>>> more. So the performance of -d 31 is close to that of serial processing.
>>>
>>> The new implementation is just like the following:
>>> * The basic idea is producer producing page and consumer writing page.
>>> * Each producer have a page_flag_buf list which is used for storing
>>> page's description.
>>> * The size of page_flag_buf is little so it won't take too much memory.
>>> * And all producers will share a page_data_buf array which is
>>> used for storing page's compressed data.
>>> * The main thread is the consumer. It will find the next pfn and write
>>> it into file.
>>> * The next pfn is smallest pfn in all page_flag_buf.
>>>
>>> Signed-off-by: Minoru Usui <min-usui@ti.jp.nec.com>
>>> Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
>>> ---
>>> makedumpfile.c | 320 +++++++++++++++++++++++++++++++++------------------------
>>> makedumpfile.h | 38 ++++---
>>> 2 files changed, 210 insertions(+), 148 deletions(-)
>>>
>>> diff --git a/makedumpfile.c b/makedumpfile.c
>>> index fa0b779..a826321 100644
>>> --- a/makedumpfile.c
>>> +++ b/makedumpfile.c
>>> @@ -3481,9 +3481,8 @@ initial_for_parallel()
>>> {
>>> unsigned long len_buf_out;
>>> unsigned long page_data_buf_size;
>>> - unsigned long limit_size;
>>> - int page_data_num;
>>> - int i;
>>> + struct page_flag *current;
>>> + int i, j;
>>>
>>> len_buf_out = calculate_len_buf_out(info->page_size);
>>>
>>> @@ -3553,20 +3552,7 @@ initial_for_parallel()
>>> #endif
>>> }
>>>
>>> - /*
>>> - * get a safe number of page_data
>>> - */
>>> - page_data_buf_size = MAX(len_buf_out, info->page_size);
>>> -
>>> - limit_size = (get_free_memory_size()
>>> - - MAP_REGION * info->num_threads) * 0.6;
>>> -
>>> - page_data_num = limit_size / page_data_buf_size;
>>> -
>>> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
>>> -
>>> - DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
>>> - info->num_buffers);
>>> + info->num_buffers = PAGE_DATA_NUM * info->num_threads;
>>>
>>> /*
>>> * allocate memory for page_data
>>> @@ -3579,6 +3565,7 @@ initial_for_parallel()
>>> }
>>> memset(info->page_data_buf, 0, sizeof(struct page_data) * info->num_buffers);
>>>
>>> + page_data_buf_size = MAX(len_buf_out, info->page_size);
>>> for (i = 0; i < info->num_buffers; i++) {
>>> if ((info->page_data_buf[i].buf = malloc(page_data_buf_size)) == NULL) {
>>> MSG("Can't allocate memory for buf of page_data_buf. %s\n",
>>> @@ -3588,6 +3575,36 @@ initial_for_parallel()
>>> }
>>>
>>> /*
>>> + * initial page_flag for each thread
>>> + */
>>> + if ((info->page_flag_buf = malloc(sizeof(void *) * info->num_threads))
>>> + == NULL) {
>>> + MSG("Can't allocate memory for page_flag_buf. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + memset(info->page_flag_buf, 0, sizeof(void *) * info->num_threads);
>>> +
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + if ((info->page_flag_buf[i] = calloc(1, sizeof(struct page_flag))) == NULL) {
>>> + MSG("Can't allocate memory for page_flag. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + current = info->page_flag_buf[i];
>>> +
>>> + for (j = 1; j < PAGE_FLAG_NUM; j++) {
>>> + if ((current->next = calloc(1, sizeof(struct page_flag))) == NULL) {
>>> + MSG("Can't allocate memory for page_flag. %s\n",
>>> + strerror(errno));
>>> + return FALSE;
>>> + }
>>> + current = current->next;
>>> + }
>>> + current->next = info->page_flag_buf[i];
>>> + }
>>> +
>>> + /*
>>> * initial fd_memory for threads
>>> */
>>> for (i = 0; i < info->num_threads; i++) {
>>> @@ -3612,7 +3629,8 @@ initial_for_parallel()
>>> void
>>> free_for_parallel()
>>> {
>>> - int i;
>>> + int i, j;
>>> + struct page_flag *current;
>>>
>>> if (info->threads != NULL) {
>>> for (i = 0; i < info->num_threads; i++) {
>>> @@ -3655,6 +3673,19 @@ free_for_parallel()
>>> free(info->page_data_buf);
>>> }
>>>
>>> + if (info->page_flag_buf != NULL) {
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + for (j = 0; j < PAGE_FLAG_NUM; j++) {
>>> + if (info->page_flag_buf[i] != NULL) {
>>> + current = info->page_flag_buf[i];
>>> + info->page_flag_buf[i] = current->next;
>>> + free(current);
>>> + }
>>> + }
>>> + }
>>> + free(info->page_flag_buf);
>>> + }
>>> +
>>> if (info->parallel_info == NULL)
>>> return;
>>>
>>> @@ -7075,11 +7106,11 @@ void *
>>> kdump_thread_function_cyclic(void *arg) {
>>> void *retval = PTHREAD_FAIL;
>>> struct thread_args *kdump_thread_args = (struct thread_args *)arg;
>>> - struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>>> + volatile struct page_data *page_data_buf = kdump_thread_args->page_data_buf;
>>> + volatile struct page_flag *page_flag_buf = kdump_thread_args->page_flag_buf;
>>> struct cycle *cycle = kdump_thread_args->cycle;
>>> - int page_data_num = kdump_thread_args->page_data_num;
>>> - mdf_pfn_t pfn;
>>> - int index;
>>> + mdf_pfn_t pfn = cycle->start_pfn;
>>> + int index = kdump_thread_args->thread_num;
>>> int buf_ready;
>>> int dumpable;
>>> int fd_memory = 0;
>>> @@ -7125,47 +7156,48 @@ kdump_thread_function_cyclic(void *arg) {
>>> kdump_thread_args->thread_num);
>>> }
>>>
>>> - while (1) {
>>> - /* get next pfn */
>>> - pthread_mutex_lock(&info->current_pfn_mutex);
>>> - pfn = info->current_pfn;
>>> - info->current_pfn++;
>>> - pthread_mutex_unlock(&info->current_pfn_mutex);
>>> -
>>> - if (pfn >= kdump_thread_args->end_pfn)
>>> - break;
>>> -
>>> - index = -1;
>>> + /*
>>> + * filtered page won't take anything
>>> + * unfiltered zero page will only take a page_flag_buf
>>> + * unfiltered non-zero page will take a page_flag_buf and a page_data_buf
>>> + */
>>> + while (pfn < cycle->end_pfn) {
>>> buf_ready = FALSE;
>>>
>>> + pthread_mutex_lock(&info->page_data_mutex);
>>> + while (page_data_buf[index].used != FALSE) {
>>> + index = (index + 1) % info->num_buffers;
>>> + }
>>> + page_data_buf[index].used = TRUE;
>>> + pthread_mutex_unlock(&info->page_data_mutex);
>>> +
>>> while (buf_ready == FALSE) {
>>> pthread_testcancel();
>>> -
>>> - index = pfn % page_data_num;
>>> -
>>> - if (pfn - info->consumed_pfn > info->num_buffers)
>>> + if (page_flag_buf->ready == FLAG_READY)
>>> continue;
>>>
>>> - if (page_data_buf[index].ready != 0)
>>> - continue;
>>> -
>>> - pthread_mutex_lock(&page_data_buf[index].mutex);
>>> -
>>> - if (page_data_buf[index].ready != 0)
>>> - goto unlock;
>>> -
>>> - buf_ready = TRUE;
>>> + /* get next dumpable pfn */
>>> + pthread_mutex_lock(&info->current_pfn_mutex);
>>> + for (pfn = info->current_pfn; pfn < cycle->end_pfn; pfn++) {
>>> + dumpable = is_dumpable(
>>> + info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>>> + pfn,
>>> + cycle);
>>> + if (dumpable)
>>> + break;
>>> + }
>>> + info->current_pfn = pfn + 1;
>>>
>>> - page_data_buf[index].pfn = pfn;
>>> - page_data_buf[index].ready = 1;
>>> + page_flag_buf->pfn = pfn;
>>> + page_flag_buf->ready = FLAG_FILLING;
>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>>> + sem_post(&info->page_flag_buf_sem);
>>>
>>> - dumpable = is_dumpable(
>>> - info->fd_bitmap ? &bitmap_parallel : info->bitmap2,
>>> - pfn,
>>> - cycle);
>>> - page_data_buf[index].dumpable = dumpable;
>>> - if (!dumpable)
>>> - goto unlock;
>>> + if (pfn >= cycle->end_pfn) {
>>> + info->current_pfn = cycle->end_pfn;
>>> + page_data_buf[index].used = FALSE;
>>> + break;
>>> + }
>>>
>>> if (!read_pfn_parallel(fd_memory, pfn, buf,
>>> &bitmap_memory_parallel,
>>> @@ -7178,11 +7210,11 @@ kdump_thread_function_cyclic(void *arg) {
>>>
>>> if ((info->dump_level & DL_EXCLUDE_ZERO)
>>> && is_zero_page(buf, info->page_size)) {
>>> - page_data_buf[index].zero = TRUE;
>>> - goto unlock;
>>> + page_flag_buf->zero = TRUE;
>>> + goto next;
>>> }
>>>
>>> - page_data_buf[index].zero = FALSE;
>>> + page_flag_buf->zero = FALSE;
>>>
>>> /*
>>> * Compress the page data.
>>> @@ -7232,12 +7264,14 @@ kdump_thread_function_cyclic(void *arg) {
>>> page_data_buf[index].size = info->page_size;
>>> memcpy(page_data_buf[index].buf, buf, info->page_size);
>>> }
>>> -unlock:
>>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>>> + page_flag_buf->index = index;
>>> + buf_ready = TRUE;
>>> +next:
>>> + page_flag_buf->ready = FLAG_READY;
>>> + page_flag_buf = page_flag_buf->next;
>>>
>>> }
>>> }
>>> -
>>> retval = NULL;
>>>
>>> fail:
>>> @@ -7265,14 +7299,15 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> struct page_desc pd;
>>> struct timeval tv_start;
>>> struct timeval last, new;
>>> - unsigned long long consuming_pfn;
>>> pthread_t **threads = NULL;
>>> struct thread_args *kdump_thread_args = NULL;
>>> void *thread_result;
>>> - int page_data_num;
>>> + int page_buf_num;
>>> struct page_data *page_data_buf = NULL;
>>> int i;
>>> int index;
>>> + int end_count, consuming;
>>> + mdf_pfn_t current_pfn, temp_pfn;
>>>
>>> if (info->flag_elf_dumpfile)
>>> return FALSE;
>>> @@ -7284,13 +7319,6 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> goto out;
>>> }
>>>
>>> - res = pthread_mutex_init(&info->consumed_pfn_mutex, NULL);
>>> - if (res != 0) {
>>> - ERRMSG("Can't initialize consumed_pfn_mutex. %s\n",
>>> - strerror(res));
>>> - goto out;
>>> - }
>>> -
>>> res = pthread_mutex_init(&info->filter_mutex, NULL);
>>> if (res != 0) {
>>> ERRMSG("Can't initialize filter_mutex. %s\n", strerror(res));
>>> @@ -7314,36 +7342,23 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> end_pfn = cycle->end_pfn;
>>>
>>> info->current_pfn = start_pfn;
>>> - info->consumed_pfn = start_pfn - 1;
>>>
>>> threads = info->threads;
>>> kdump_thread_args = info->kdump_thread_args;
>>>
>>> - page_data_num = info->num_buffers;
>>> + page_buf_num = info->num_buffers;
>>> page_data_buf = info->page_data_buf;
>>> + pthread_mutex_init(&info->page_data_mutex, NULL);
>>> + sem_init(&info->page_flag_buf_sem, 0, 0);
>>>
>>> - for (i = 0; i < page_data_num; i++) {
>>> - /*
>>> - * producer will use pfn in page_data_buf to decide the
>>> - * consumed pfn
>>> - */
>>> - page_data_buf[i].pfn = start_pfn - 1;
>>> - page_data_buf[i].ready = 0;
>>> - res = pthread_mutex_init(&page_data_buf[i].mutex, NULL);
>>> - if (res != 0) {
>>> - ERRMSG("Can't initialize mutex of page_data_buf. %s\n",
>>> - strerror(res));
>>> - goto out;
>>> - }
>>> - }
>>> + for (i = 0; i < page_buf_num; i++)
>>> + page_data_buf[i].used = FALSE;
>>>
>>> for (i = 0; i < info->num_threads; i++) {
>>> kdump_thread_args[i].thread_num = i;
>>> kdump_thread_args[i].len_buf_out = len_buf_out;
>>> - kdump_thread_args[i].start_pfn = start_pfn;
>>> - kdump_thread_args[i].end_pfn = end_pfn;
>>> - kdump_thread_args[i].page_data_num = page_data_num;
>>> kdump_thread_args[i].page_data_buf = page_data_buf;
>>> + kdump_thread_args[i].page_flag_buf = info->page_flag_buf[i];
>>> kdump_thread_args[i].cycle = cycle;
>>>
>>> res = pthread_create(threads[i], NULL,
>>> @@ -7356,55 +7371,86 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> }
>>> }
>>>
>>> - consuming_pfn = start_pfn;
>>> - index = -1;
>>> + end_count = 0;
>>> + while (1) {
>>> + consuming = 0;
>>>
>>> - gettimeofday(&last, NULL);
>>> + /*
>>> + * The basic idea is producer producing page and consumer writing page.
>>> + * Each producer have a page_flag_buf list which is used for storing page's description.
>>> + * The size of page_flag_buf is little so it won't take too much memory.
>>> + * And all producers will share a page_data_buf array which is used for storing page's compressed data.
>>> + * The main thread is the consumer. It will find the next pfn and write it into file.
>>> + * The next pfn is smallest pfn in all page_flag_buf.
>>> + */
>>> + sem_wait(&info->page_flag_buf_sem);
>>> + gettimeofday(&last, NULL);
>>> + while (1) {
>>> + current_pfn = end_pfn;
>>>
>>> - while (consuming_pfn < end_pfn) {
>>> - index = consuming_pfn % page_data_num;
>>> + /*
>>> + * page_flag_buf is in circular linked list.
>>> + * The array info->page_flag_buf[] records the current page_flag_buf in each thread's
>>> + * page_flag_buf list.
>>> + * consuming is used for recording in which thread the pfn is the smallest.
>>> + * current_pfn is used for recording the value of pfn when checking the pfn.
>>> + */
>>> + for (i = 0; i < info->num_threads; i++) {
>>> + if (info->page_flag_buf[i]->ready == FLAG_UNUSED)
>>> + continue;
>>> + temp_pfn = info->page_flag_buf[i]->pfn;
>>>
>>> - gettimeofday(&new, NULL);
>>> - if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>>> - ERRMSG("Can't get data of pfn %llx.\n", consuming_pfn);
>>> - goto out;
>>> - }
>>> + /*
>>> + * count how many threads have reached the end.
>>> + */
>>> + if (temp_pfn >= end_pfn) {
>>> + info->page_flag_buf[i]->ready = FLAG_UNUSED;
>>> + end_count++;
>>> + continue;
>>> + }
>>>
>>> - /*
>>> - * check pfn first without mutex locked to reduce the time
>>> - * trying to lock the mutex
>>> - */
>>> - if (page_data_buf[index].pfn != consuming_pfn)
>>> - continue;
>>> + if (current_pfn < temp_pfn)
>>> + continue;
>>>
>>> - if (pthread_mutex_trylock(&page_data_buf[index].mutex) != 0)
>>> - continue;
>>> + consuming = i;
>>> + current_pfn = temp_pfn;
>>> + }
>>>
>>> - /* check whether the found one is ready to be consumed */
>>> - if (page_data_buf[index].pfn != consuming_pfn ||
>>> - page_data_buf[index].ready != 1) {
>>> - goto unlock;
>>> + /*
>>> + * If all the threads have reached the end, we will finish writing.
>>> + */
>>> + if (end_count >= info->num_threads)
>>> + goto finish;
>>> +
>>> + /*
>>> + * If the page_flag_buf is not ready, the pfn recorded may be changed.
>>> + * So we should recheck.
>>> + */
>>> + if (info->page_flag_buf[consuming]->ready != FLAG_READY) {
>>> + gettimeofday(&new, NULL);
>>> + if (new.tv_sec - last.tv_sec > WAIT_TIME) {
>>> + ERRMSG("Can't get data of pfn.\n");
>>> + goto out;
>>> + }
>>> + continue;
>>> + }
>>> +
>>> + if (current_pfn == info->page_flag_buf[consuming]->pfn)
>>> + break;
>>> }
>>>
>>> if ((num_dumped % per) == 0)
>>> print_progress(PROGRESS_COPY, num_dumped, info->num_dumpable);
>>>
>>> - /* next pfn is found, refresh last here */
>>> - last = new;
>>> - consuming_pfn++;
>>> - info->consumed_pfn++;
>>> - page_data_buf[index].ready = 0;
>>> -
>>> - if (page_data_buf[index].dumpable == FALSE)
>>> - goto unlock;
>>> -
>>> num_dumped++;
>>>
>>> - if (page_data_buf[index].zero == TRUE) {
>>> +
>>> + if (info->page_flag_buf[consuming]->zero == TRUE) {
>>> if (!write_cache(cd_header, pd_zero, sizeof(page_desc_t)))
>>> goto out;
>>> pfn_zero++;
>>> } else {
>>> + index = info->page_flag_buf[consuming]->index;
>>> pd.flags = page_data_buf[index].flags;
>>> pd.size = page_data_buf[index].size;
>>> pd.page_flags = 0;
>>> @@ -7420,12 +7466,12 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> */
>>> if (!write_cache(cd_page, page_data_buf[index].buf, pd.size))
>>> goto out;
>>> -
>>> + page_data_buf[index].used = FALSE;
>>> }
>>> -unlock:
>>> - pthread_mutex_unlock(&page_data_buf[index].mutex);
>>> + info->page_flag_buf[consuming]->ready = FLAG_UNUSED;
>>> + info->page_flag_buf[consuming] = info->page_flag_buf[consuming]->next;
>>> }
>>> -
>>> +finish:
>>> ret = TRUE;
>>> /*
>>> * print [100 %]
>>> @@ -7463,15 +7509,9 @@ out:
>>> }
>>> }
>>>
>>> - if (page_data_buf != NULL) {
>>> - for (i = 0; i < page_data_num; i++) {
>>> - pthread_mutex_destroy(&page_data_buf[i].mutex);
>>> - }
>>> - }
>>> -
>>> + sem_destroy(&info->page_flag_buf_sem);
>>> pthread_rwlock_destroy(&info->usemmap_rwlock);
>>> pthread_mutex_destroy(&info->filter_mutex);
>>> - pthread_mutex_destroy(&info->consumed_pfn_mutex);
>>> pthread_mutex_destroy(&info->current_pfn_mutex);
>>>
>>> return ret;
>>> @@ -7564,6 +7604,7 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
>>> num_dumped++;
>>> if (!read_pfn(pfn, buf))
>>> goto out;
>>> +
>>> filter_data_buffer(buf, pfn_to_paddr(pfn), info->page_size);
>>>
>>> /*
>>> @@ -10201,7 +10242,6 @@ out:
>>> return free_size;
>>> }
>>>
>>> -
>>> /*
>>> * Choose the less value of the three below as the size of cyclic buffer.
>>> * - the size enough for storing the 1st or 2nd bitmap for the whole of vmcore
>>> @@ -10223,6 +10263,20 @@ calculate_cyclic_buffer_size(void) {
>>> * free memory for safety.
>>> */
>>> limit_size = get_free_memory_size() * 0.6;
>>> +
>>> + /*
>>> + * Recalculate the limit_size according to num_threads.
>>> + * And reset num_threads if there is not enough memory.
>>> + */
>>> + if (limit_size - maximum_size < THREAD_REGION * info->num_threads) {
>>> + MSG("There isn't enough memory for %d threads.\n", info->num_threads);
>>> +
>>> + info->num_threads = MAX(0, limit_size - maximum_size) / THREAD_REGION;
>>> + MSG("--num_threads is set to %d.\n", info->num_threads);
>>> + }
>>> +
>>> + limit_size = limit_size - THREAD_REGION * info->num_threads;
>>> +
>>> /* Try to keep both 1st and 2nd bitmap at the same time. */
>>> bitmap_size = info->max_mapnr * 2 / BITPERBYTE;
>>>
>>> diff --git a/makedumpfile.h b/makedumpfile.h
>>> index e0b5bbf..322d31b 100644
>>> --- a/makedumpfile.h
>>> +++ b/makedumpfile.h
>>> @@ -44,6 +44,7 @@
>>> #include "print_info.h"
>>> #include "sadump_mod.h"
>>> #include <pthread.h>
>>> +#include <semaphore.h>
>>>
>>> /*
>>> * Result of command
>>> @@ -974,10 +975,11 @@ typedef unsigned long long int ulonglong;
>>> * for parallel process
>>> */
>>>
>>> -#define PAGE_DATA_NUM (50)
>>> +#define PAGE_FLAG_NUM (20)
>>> +#define PAGE_DATA_NUM (5)
>>> #define WAIT_TIME (60 * 10)
>>> #define PTHREAD_FAIL ((void *)-2)
>>> -#define NUM_BUFFERS (50)
>>> +#define THREAD_REGION (200 * 1024)
>>>
>>> struct mmap_cache {
>>> char *mmap_buf;
>>> @@ -985,28 +987,33 @@ struct mmap_cache {
>>> off_t mmap_end_offset;
>>> };
>>>
>>> +enum {
>>> + FLAG_UNUSED,
>>> + FLAG_READY,
>>> + FLAG_FILLING
>>> +};
>>> +struct page_flag {
>>> + mdf_pfn_t pfn;
>>> + char zero;
>>> + char ready;
>>> + short index;
>>> + struct page_flag *next;
>>> +};
>>> +
>>> struct page_data
>>> {
>>> - mdf_pfn_t pfn;
>>> - int dumpable;
>>> - int zero;
>>> - unsigned int flags;
>>> long size;
>>> unsigned char *buf;
>>> - pthread_mutex_t mutex;
>>> - /*
>>> - * whether the page_data is ready to be consumed
>>> - */
>>> - int ready;
>>> + int flags;
>>> + int used;
>>> };
>>>
>>> struct thread_args {
>>> int thread_num;
>>> unsigned long len_buf_out;
>>> - mdf_pfn_t start_pfn, end_pfn;
>>> - int page_data_num;
>>> struct cycle *cycle;
>>> struct page_data *page_data_buf;
>>> + struct page_flag *page_flag_buf;
>>> };
>>>
>>> /*
>>> @@ -1295,11 +1302,12 @@ struct DumpInfo {
>>> pthread_t **threads;
>>> struct thread_args *kdump_thread_args;
>>> struct page_data *page_data_buf;
>>> + struct page_flag **page_flag_buf;
>>> + sem_t page_flag_buf_sem;
>>> pthread_rwlock_t usemmap_rwlock;
>>> mdf_pfn_t current_pfn;
>>> pthread_mutex_t current_pfn_mutex;
>>> - mdf_pfn_t consumed_pfn;
>>> - pthread_mutex_t consumed_pfn_mutex;
>>> + pthread_mutex_t page_data_mutex;
>>> pthread_mutex_t filter_mutex;
>>> };
>>> extern struct DumpInfo *info;
>>>
>>
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^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2016-04-15 10:11 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-04-14 5:42 [PATCH v6] Improve the performance of --num-threads -d 31 Zhou Wenjian
2016-04-14 5:56 ` "Zhou, Wenjian/周文剑"
2016-04-14 9:57 ` Minfei Huang
2016-04-15 0:17 ` "Zhou, Wenjian/周文剑"
2016-04-15 2:09 ` Minfei Huang
2016-04-15 5:24 ` Atsushi Kumagai
2016-04-15 10:09 ` "Zhou, Wenjian/周文剑"
2016-04-15 2:39 ` Minfei Huang
2016-04-15 2:38 ` "Zhou, Wenjian/周文剑"
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