* [PATCH v3] Improve the performance of --num-threads -d 31
@ 2016-03-04 8:35 Zhou Wenjian
2016-03-04 9:07 ` "Zhou, Wenjian/周文剑"
2016-03-07 7:04 ` Minfei Huang
0 siblings, 2 replies; 13+ messages in thread
From: Zhou Wenjian @ 2016-03-04 8:35 UTC (permalink / raw)
To: kexec
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 | 300 +++++++++++++++++++++++++++++++++++----------------------
makedumpfile.h | 33 ++++---
2 files changed, 203 insertions(+), 130 deletions(-)
diff --git a/makedumpfile.c b/makedumpfile.c
index fa0b779..d75f7f7 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3483,7 +3483,8 @@ initial_for_parallel()
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);
@@ -3560,10 +3561,16 @@ initial_for_parallel()
limit_size = (get_free_memory_size()
- MAP_REGION * info->num_threads) * 0.6;
+ if (limit_size < 0) {
+ MSG("Free memory is not enough for multi-threads\n");
+ return FALSE;
+ }
page_data_num = limit_size / page_data_buf_size;
+ info->num_buffers = 3 * info->num_threads;
- info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
+ info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
+ info->num_buffers = MIN(info->num_buffers, page_data_num);
DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
info->num_buffers);
@@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
- continue;
-
- if (page_data_buf[index].ready != 0)
+ if (page_flag_buf->ready == FLAG_READY)
continue;
- pthread_mutex_lock(&page_data_buf[index].mutex);
-
- if (page_data_buf[index].ready != 0)
- goto unlock;
+ /* 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;
- buf_ready = TRUE;
+ page_flag_buf->pfn = pfn;
+ page_flag_buf->ready = FLAG_FILLING;
+ pthread_mutex_unlock(&info->current_pfn_mutex);
- page_data_buf[index].pfn = pfn;
- page_data_buf[index].ready = 1;
- 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 +7230,11 @@ 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.
@@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
page_data_buf[index].flags =
DUMP_DH_COMPRESSED_LZO;
page_data_buf[index].size = size_out;
+
memcpy(page_data_buf[index].buf, buf_out, size_out);
#endif
#ifdef USESNAPPY
@@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
+ mdf_pfn_t current_pfn, temp_pfn;
if (info->flag_elf_dumpfile)
return FALSE;
@@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
- 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
}
}
- consuming_pfn = start_pfn;
- index = -1;
+ end_count = 0;
+ while (1) {
+ consuming = 0;
+ check_count = 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.
+ */
+ 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;
+ check_count++;
+ consuming = i;
+ current_pfn = temp_pfn;
+ }
+
+ /*
+ * If all the threads have reached the end, we will finish writing.
+ */
+ if (end_count >= info->num_threads)
+ goto finish;
+
+ /*
+ * Since it has the probabilty that there is no page_flag_buf being ready,
+ * we should recheck if it happens.
+ */
+ if (check_count == 0)
+ continue;
+
+ /*
+ * 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;
+ }
- /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
}
}
- if (page_data_buf != NULL) {
- for (i = 0; i < page_data_num; i++) {
- pthread_mutex_destroy(&page_data_buf[i].mutex);
- }
- }
-
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 +7631,7 @@ 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);
/*
diff --git a/makedumpfile.h b/makedumpfile.h
index e0b5bbf..5865827 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
#define PAGE_DATA_NUM (50)
#define WAIT_TIME (60 * 10)
#define PTHREAD_FAIL ((void *)-2)
-#define NUM_BUFFERS (50)
+#define NUM_BUFFERS (20)
struct mmap_cache {
char *mmap_buf;
@@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
pthread_t **threads;
struct thread_args *kdump_thread_args;
struct page_data *page_data_buf;
+ struct page_flag **page_flag_buf;
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] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-04 8:35 [PATCH v3] Improve the performance of --num-threads -d 31 Zhou Wenjian
@ 2016-03-04 9:07 ` "Zhou, Wenjian/周文剑"
2016-03-07 0:17 ` "Zhou, Wenjian/周文剑"
2016-03-07 7:04 ` Minfei Huang
1 sibling, 1 reply; 13+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-03-04 9:07 UTC (permalink / raw)
To: Minfei Huang, Minoru Usui; +Cc: kexec
Hello Minfei and Minoru,
This is a reply to the previous letters.
Sorry for so late.
And it is also an introduction of the patch v3.
About performance:
I modified the patch after reading Minoru's code.
Thanks Minoru, it has better performance now.
About bugs:
There are two bugs in the patch v2.
First is reported by Minfei.
Minoru's explanation and solution are right.
But I used another solution.
+ if (pfn >= kdump_thread_args->end_pfn) {
+ page_data_buf[index].used = FALSE;
+ page_flag_buf->ready = FLAG_READY;
+ break;
+ }
The bug is caused by the above code.
Just remove "page_flag_buf->ready = FLAG_READY;" is OK.
Second bug is what I met.
If run makedumpfile a lot of times, a few pages' data will not be correct.
I fix it by using "volatile" and info->page_data_mutex.
So I delete the original mutex in page_data_buf. It can also use less memory.
I have run it 500 times and haven't got any wrong page data.
--
Thanks
Zhou
On 03/04/2016 04:35 PM, Zhou Wenjian wrote:
> 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 | 300 +++++++++++++++++++++++++++++++++++----------------------
> makedumpfile.h | 33 ++++---
> 2 files changed, 203 insertions(+), 130 deletions(-)
>
> diff --git a/makedumpfile.c b/makedumpfile.c
> index fa0b779..d75f7f7 100644
> --- a/makedumpfile.c
> +++ b/makedumpfile.c
> @@ -3483,7 +3483,8 @@ initial_for_parallel()
> 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);
>
> @@ -3560,10 +3561,16 @@ initial_for_parallel()
>
> limit_size = (get_free_memory_size()
> - MAP_REGION * info->num_threads) * 0.6;
> + if (limit_size < 0) {
> + MSG("Free memory is not enough for multi-threads\n");
> + return FALSE;
> + }
>
> page_data_num = limit_size / page_data_buf_size;
> + info->num_buffers = 3 * info->num_threads;
>
> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
> + info->num_buffers = MIN(info->num_buffers, page_data_num);
>
> DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> info->num_buffers);
> @@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
> - continue;
> -
> - if (page_data_buf[index].ready != 0)
> + if (page_flag_buf->ready == FLAG_READY)
> continue;
>
> - pthread_mutex_lock(&page_data_buf[index].mutex);
> -
> - if (page_data_buf[index].ready != 0)
> - goto unlock;
> + /* 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;
>
> - buf_ready = TRUE;
> + page_flag_buf->pfn = pfn;
> + page_flag_buf->ready = FLAG_FILLING;
> + pthread_mutex_unlock(&info->current_pfn_mutex);
>
> - page_data_buf[index].pfn = pfn;
> - page_data_buf[index].ready = 1;
>
> - 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 +7230,11 @@ 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.
> @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
> page_data_buf[index].flags =
> DUMP_DH_COMPRESSED_LZO;
> page_data_buf[index].size = size_out;
> +
> memcpy(page_data_buf[index].buf, buf_out, size_out);
> #endif
> #ifdef USESNAPPY
> @@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
> + mdf_pfn_t current_pfn, temp_pfn;
>
> if (info->flag_elf_dumpfile)
> return FALSE;
> @@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
>
> - 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> }
> }
>
> - consuming_pfn = start_pfn;
> - index = -1;
> + end_count = 0;
> + while (1) {
> + consuming = 0;
> + check_count = 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.
> + */
> + 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;
> + check_count++;
> + consuming = i;
> + current_pfn = temp_pfn;
> + }
> +
> + /*
> + * If all the threads have reached the end, we will finish writing.
> + */
> + if (end_count >= info->num_threads)
> + goto finish;
> +
> + /*
> + * Since it has the probabilty that there is no page_flag_buf being ready,
> + * we should recheck if it happens.
> + */
> + if (check_count == 0)
> + continue;
> +
> + /*
> + * 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;
> + }
>
> - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
> }
> }
>
> - if (page_data_buf != NULL) {
> - for (i = 0; i < page_data_num; i++) {
> - pthread_mutex_destroy(&page_data_buf[i].mutex);
> - }
> - }
> -
> 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 +7631,7 @@ 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);
>
> /*
> diff --git a/makedumpfile.h b/makedumpfile.h
> index e0b5bbf..5865827 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
> #define PAGE_DATA_NUM (50)
> #define WAIT_TIME (60 * 10)
> #define PTHREAD_FAIL ((void *)-2)
> -#define NUM_BUFFERS (50)
> +#define NUM_BUFFERS (20)
>
> struct mmap_cache {
> char *mmap_buf;
> @@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
> pthread_t **threads;
> struct thread_args *kdump_thread_args;
> struct page_data *page_data_buf;
> + struct page_flag **page_flag_buf;
> 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] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-04 9:07 ` "Zhou, Wenjian/周文剑"
@ 2016-03-07 0:17 ` "Zhou, Wenjian/周文剑"
2016-03-07 5:53 ` Minfei Huang
0 siblings, 1 reply; 13+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-03-07 0:17 UTC (permalink / raw)
To: Minfei Huang, Minoru Usui; +Cc: kexec
On 03/04/2016 05:07 PM, "Zhou, Wenjian/周文剑" wrote:
> Hello Minfei and Minoru,
>
> This is a reply to the previous letters.
> Sorry for so late.
> And it is also an introduction of the patch v3.
>
> About performance:
> I modified the patch after reading Minoru's code.
> Thanks Minoru, it has better performance now.
>
> About bugs:
> There are two bugs in the patch v2.
> First is reported by Minfei.
> Minoru's explanation and solution are right.
> But I used another solution.
> + if (pfn >= kdump_thread_args->end_pfn) {
> + page_data_buf[index].used = FALSE;
> + page_flag_buf->ready = FLAG_READY;
> + break;
> + }
> The bug is caused by the above code.
> Just remove "page_flag_buf->ready = FLAG_READY;" is OK.
>
> Second bug is what I met.
> If run makedumpfile a lot of times, a few pages' data will not be correct.
> I fix it by using "volatile" and info->page_data_mutex.
> So I delete the original mutex in page_data_buf. It can also use less memory.
> I have run it 500 times and haven't got any wrong page data.
>
Sorry, the second bug still exists.
--
Thanks
Zhou
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 0:17 ` "Zhou, Wenjian/周文剑"
@ 2016-03-07 5:53 ` Minfei Huang
0 siblings, 0 replies; 13+ messages in thread
From: Minfei Huang @ 2016-03-07 5:53 UTC (permalink / raw)
To: "Zhou, Wenjian/周文剑"; +Cc: Minoru Usui, kexec
On 03/07/16 at 08:17am, "Zhou, Wenjian/周文剑" wrote:
> On 03/04/2016 05:07 PM, "Zhou, Wenjian/周文剑" wrote:
> >Second bug is what I met.
> >If run makedumpfile a lot of times, a few pages' data will not be correct.
> >I fix it by using "volatile" and info->page_data_mutex.
> >So I delete the original mutex in page_data_buf. It can also use less memory.
> >I have run it 500 times and haven't got any wrong page data.
> >
>
> Sorry, the second bug still exists.
Hi, Wenjian.
Due to the unresolved issue, I will hang on the test and wait for your
new update.
Thanks
Minfei
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-04 8:35 [PATCH v3] Improve the performance of --num-threads -d 31 Zhou Wenjian
2016-03-04 9:07 ` "Zhou, Wenjian/周文剑"
@ 2016-03-07 7:04 ` Minfei Huang
2016-03-07 7:36 ` Minoru Usui
1 sibling, 1 reply; 13+ messages in thread
From: Minfei Huang @ 2016-03-07 7:04 UTC (permalink / raw)
To: Zhou Wenjian; +Cc: kexec
Hi, Wenjian.
Since your patch applied Minoru Usui's draft patch, I have vierified it.
And it works well under 4T memory.
applied makedumpfile with option -d 31
real 3m48.681s
applied makedumpfile with option -d 31 --num-threads 32
real 3m3.533s
original makedumpfile with option -d 31
real 3m57.163s
Now with or without option --num-thread, it takes almost same time.
Thanks
Minfei
On 03/04/16 at 04:35pm, Zhou Wenjian wrote:
> 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 | 300 +++++++++++++++++++++++++++++++++++----------------------
> makedumpfile.h | 33 ++++---
> 2 files changed, 203 insertions(+), 130 deletions(-)
>
> diff --git a/makedumpfile.c b/makedumpfile.c
> index fa0b779..d75f7f7 100644
> --- a/makedumpfile.c
> +++ b/makedumpfile.c
> @@ -3483,7 +3483,8 @@ initial_for_parallel()
> 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);
>
> @@ -3560,10 +3561,16 @@ initial_for_parallel()
>
> limit_size = (get_free_memory_size()
> - MAP_REGION * info->num_threads) * 0.6;
> + if (limit_size < 0) {
> + MSG("Free memory is not enough for multi-threads\n");
> + return FALSE;
> + }
>
> page_data_num = limit_size / page_data_buf_size;
> + info->num_buffers = 3 * info->num_threads;
>
> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
> + info->num_buffers = MIN(info->num_buffers, page_data_num);
>
> DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> info->num_buffers);
> @@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
> - continue;
> -
> - if (page_data_buf[index].ready != 0)
> + if (page_flag_buf->ready == FLAG_READY)
> continue;
>
> - pthread_mutex_lock(&page_data_buf[index].mutex);
> -
> - if (page_data_buf[index].ready != 0)
> - goto unlock;
> + /* 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;
>
> - buf_ready = TRUE;
> + page_flag_buf->pfn = pfn;
> + page_flag_buf->ready = FLAG_FILLING;
> + pthread_mutex_unlock(&info->current_pfn_mutex);
>
> - page_data_buf[index].pfn = pfn;
> - page_data_buf[index].ready = 1;
>
> - 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 +7230,11 @@ 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.
> @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
> page_data_buf[index].flags =
> DUMP_DH_COMPRESSED_LZO;
> page_data_buf[index].size = size_out;
> +
> memcpy(page_data_buf[index].buf, buf_out, size_out);
> #endif
> #ifdef USESNAPPY
> @@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
> + mdf_pfn_t current_pfn, temp_pfn;
>
> if (info->flag_elf_dumpfile)
> return FALSE;
> @@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
>
> - 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> }
> }
>
> - consuming_pfn = start_pfn;
> - index = -1;
> + end_count = 0;
> + while (1) {
> + consuming = 0;
> + check_count = 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.
> + */
> + 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;
> + check_count++;
> + consuming = i;
> + current_pfn = temp_pfn;
> + }
> +
> + /*
> + * If all the threads have reached the end, we will finish writing.
> + */
> + if (end_count >= info->num_threads)
> + goto finish;
> +
> + /*
> + * Since it has the probabilty that there is no page_flag_buf being ready,
> + * we should recheck if it happens.
> + */
> + if (check_count == 0)
> + continue;
> +
> + /*
> + * 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;
> + }
>
> - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
> }
> }
>
> - if (page_data_buf != NULL) {
> - for (i = 0; i < page_data_num; i++) {
> - pthread_mutex_destroy(&page_data_buf[i].mutex);
> - }
> - }
> -
> 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 +7631,7 @@ 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);
>
> /*
> diff --git a/makedumpfile.h b/makedumpfile.h
> index e0b5bbf..5865827 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
> #define PAGE_DATA_NUM (50)
> #define WAIT_TIME (60 * 10)
> #define PTHREAD_FAIL ((void *)-2)
> -#define NUM_BUFFERS (50)
> +#define NUM_BUFFERS (20)
>
> struct mmap_cache {
> char *mmap_buf;
> @@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
> pthread_t **threads;
> struct thread_args *kdump_thread_args;
> struct page_data *page_data_buf;
> + struct page_flag **page_flag_buf;
> 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
>
>
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
kexec mailing list
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http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 7:04 ` Minfei Huang
@ 2016-03-07 7:36 ` Minoru Usui
2016-03-07 8:16 ` Minoru Usui
2016-03-07 8:22 ` "Zhou, Wenjian/周文?"
0 siblings, 2 replies; 13+ messages in thread
From: Minoru Usui @ 2016-03-07 7:36 UTC (permalink / raw)
To: Minfei Huang, Zhou Wenjian; +Cc: kexec@lists.infradead.org
Hi, Minfei, Zhou
> -----Original Message-----
> From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of Minfei Huang
> Sent: Monday, March 07, 2016 4:05 PM
> To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> Cc: kexec@lists.infradead.org
> Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
>
> Hi, Wenjian.
>
> Since your patch applied Minoru Usui's draft patch, I have vierified it.
> And it works well under 4T memory.
>
> applied makedumpfile with option -d 31
> real 3m48.681s
>
> applied makedumpfile with option -d 31 --num-threads 32
> real 3m3.533s
>
> original makedumpfile with option -d 31
> real 3m57.163s
>
> Now with or without option --num-thread, it takes almost same time.
Thank you for your test on big memory machine.
I am relieved to see your test results.
Zhou, my patch may not be sophisticated,
but getting mutex logic is robust, it works well and its performance is not bad.
I think it reaches the goal of the original purpose.
I understand you don't like getting mutex, but if you are debugging now, could you apply my approach?
Thanks,
Minoru Usui
> Thanks
> Minfei
>
> On 03/04/16 at 04:35pm, Zhou Wenjian wrote:
> > 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 | 300 +++++++++++++++++++++++++++++++++++----------------------
> > makedumpfile.h | 33 ++++---
> > 2 files changed, 203 insertions(+), 130 deletions(-)
> >
> > diff --git a/makedumpfile.c b/makedumpfile.c
> > index fa0b779..d75f7f7 100644
> > --- a/makedumpfile.c
> > +++ b/makedumpfile.c
> > @@ -3483,7 +3483,8 @@ initial_for_parallel()
> > 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);
> >
> > @@ -3560,10 +3561,16 @@ initial_for_parallel()
> >
> > limit_size = (get_free_memory_size()
> > - MAP_REGION * info->num_threads) * 0.6;
> > + if (limit_size < 0) {
> > + MSG("Free memory is not enough for multi-threads\n");
> > + return FALSE;
> > + }
> >
> > page_data_num = limit_size / page_data_buf_size;
> > + info->num_buffers = 3 * info->num_threads;
> >
> > - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> > + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
> > + info->num_buffers = MIN(info->num_buffers, page_data_num);
> >
> > DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> > info->num_buffers);
> > @@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
> > - continue;
> > -
> > - if (page_data_buf[index].ready != 0)
> > + if (page_flag_buf->ready == FLAG_READY)
> > continue;
> >
> > - pthread_mutex_lock(&page_data_buf[index].mutex);
> > -
> > - if (page_data_buf[index].ready != 0)
> > - goto unlock;
> > + /* 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;
> >
> > - buf_ready = TRUE;
> > + page_flag_buf->pfn = pfn;
> > + page_flag_buf->ready = FLAG_FILLING;
> > + pthread_mutex_unlock(&info->current_pfn_mutex);
> >
> > - page_data_buf[index].pfn = pfn;
> > - page_data_buf[index].ready = 1;
> >
> > - 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 +7230,11 @@ 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.
> > @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
> > page_data_buf[index].flags =
> > DUMP_DH_COMPRESSED_LZO;
> > page_data_buf[index].size = size_out;
> > +
> > memcpy(page_data_buf[index].buf, buf_out, size_out);
> > #endif
> > #ifdef USESNAPPY
> > @@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
> > + mdf_pfn_t current_pfn, temp_pfn;
> >
> > if (info->flag_elf_dumpfile)
> > return FALSE;
> > @@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
> >
> > - 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > }
> > }
> >
> > - consuming_pfn = start_pfn;
> > - index = -1;
> > + end_count = 0;
> > + while (1) {
> > + consuming = 0;
> > + check_count = 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.
> > + */
> > + 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;
> > + check_count++;
> > + consuming = i;
> > + current_pfn = temp_pfn;
> > + }
> > +
> > + /*
> > + * If all the threads have reached the end, we will finish writing.
> > + */
> > + if (end_count >= info->num_threads)
> > + goto finish;
> > +
> > + /*
> > + * Since it has the probabilty that there is no page_flag_buf being ready,
> > + * we should recheck if it happens.
> > + */
> > + if (check_count == 0)
> > + continue;
> > +
> > + /*
> > + * 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;
> > + }
> >
> > - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
> > }
> > }
> >
> > - if (page_data_buf != NULL) {
> > - for (i = 0; i < page_data_num; i++) {
> > - pthread_mutex_destroy(&page_data_buf[i].mutex);
> > - }
> > - }
> > -
> > 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 +7631,7 @@ 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);
> >
> > /*
> > diff --git a/makedumpfile.h b/makedumpfile.h
> > index e0b5bbf..5865827 100644
> > --- a/makedumpfile.h
> > +++ b/makedumpfile.h
> > @@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
> > #define PAGE_DATA_NUM (50)
> > #define WAIT_TIME (60 * 10)
> > #define PTHREAD_FAIL ((void *)-2)
> > -#define NUM_BUFFERS (50)
> > +#define NUM_BUFFERS (20)
> >
> > struct mmap_cache {
> > char *mmap_buf;
> > @@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
> > pthread_t **threads;
> > struct thread_args *kdump_thread_args;
> > struct page_data *page_data_buf;
> > + struct page_flag **page_flag_buf;
> > 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
> >
> >
> >
> >
> > _______________________________________________
> > 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
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 7:36 ` Minoru Usui
@ 2016-03-07 8:16 ` Minoru Usui
2016-03-07 8:39 ` Minfei Huang
2016-03-07 8:22 ` "Zhou, Wenjian/周文?"
1 sibling, 1 reply; 13+ messages in thread
From: Minoru Usui @ 2016-03-07 8:16 UTC (permalink / raw)
To: Minfei Huang, Zhou Wenjian; +Cc: kexec@lists.infradead.org
Hi, Minfei
> -----Original Message-----
> From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of Minoru Usui
> Sent: Monday, March 07, 2016 4:37 PM
> To: Minfei Huang <mhuang@redhat.com>; Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> Cc: kexec@lists.infradead.org
> Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
>
> Hi, Minfei, Zhou
>
> > -----Original Message-----
> > From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of Minfei Huang
> > Sent: Monday, March 07, 2016 4:05 PM
> > To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
> > Cc: kexec@lists.infradead.org
> > Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
> >
> > Hi, Wenjian.
> >
> > Since your patch applied Minoru Usui's draft patch, I have vierified it.
> > And it works well under 4T memory.
> >
> > applied makedumpfile with option -d 31
> > real 3m48.681s
> >
> > applied makedumpfile with option -d 31 --num-threads 32
> > real 3m3.533s
> >
> > original makedumpfile with option -d 31
> > real 3m57.163s
> >
> > Now with or without option --num-thread, it takes almost same time.
>
> Thank you for your test on big memory machine.
> I am relieved to see your test results.
I'm sorry, I may be misunderstood.
Is above result is Zhou's v3 patch or v2 + my patch?
If above result is Zhou's v3 patch, could you test v2 + my patch?
Thanks
Minoru Usui
> Zhou, my patch may not be sophisticated,
> but getting mutex logic is robust, it works well and its performance is not bad.
> I think it reaches the goal of the original purpose.
> I understand you don't like getting mutex, but if you are debugging now, could you apply my approach?
>
> Thanks,
> Minoru Usui
>
>
> > Thanks
> > Minfei
> >
> > On 03/04/16 at 04:35pm, Zhou Wenjian wrote:
> > > 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 | 300 +++++++++++++++++++++++++++++++++++----------------------
> > > makedumpfile.h | 33 ++++---
> > > 2 files changed, 203 insertions(+), 130 deletions(-)
> > >
> > > diff --git a/makedumpfile.c b/makedumpfile.c
> > > index fa0b779..d75f7f7 100644
> > > --- a/makedumpfile.c
> > > +++ b/makedumpfile.c
> > > @@ -3483,7 +3483,8 @@ initial_for_parallel()
> > > 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);
> > >
> > > @@ -3560,10 +3561,16 @@ initial_for_parallel()
> > >
> > > limit_size = (get_free_memory_size()
> > > - MAP_REGION * info->num_threads) * 0.6;
> > > + if (limit_size < 0) {
> > > + MSG("Free memory is not enough for multi-threads\n");
> > > + return FALSE;
> > > + }
> > >
> > > page_data_num = limit_size / page_data_buf_size;
> > > + info->num_buffers = 3 * info->num_threads;
> > >
> > > - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
> > > + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
> > > + info->num_buffers = MIN(info->num_buffers, page_data_num);
> > >
> > > DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
> > > info->num_buffers);
> > > @@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
> > > - continue;
> > > -
> > > - if (page_data_buf[index].ready != 0)
> > > + if (page_flag_buf->ready == FLAG_READY)
> > > continue;
> > >
> > > - pthread_mutex_lock(&page_data_buf[index].mutex);
> > > -
> > > - if (page_data_buf[index].ready != 0)
> > > - goto unlock;
> > > + /* 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;
> > >
> > > - buf_ready = TRUE;
> > > + page_flag_buf->pfn = pfn;
> > > + page_flag_buf->ready = FLAG_FILLING;
> > > + pthread_mutex_unlock(&info->current_pfn_mutex);
> > >
> > > - page_data_buf[index].pfn = pfn;
> > > - page_data_buf[index].ready = 1;
> > >
> > > - 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 +7230,11 @@ 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.
> > > @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
> > > page_data_buf[index].flags =
> > > DUMP_DH_COMPRESSED_LZO;
> > > page_data_buf[index].size = size_out;
> > > +
> > > memcpy(page_data_buf[index].buf, buf_out, size_out);
> > > #endif
> > > #ifdef USESNAPPY
> > > @@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
> > > + mdf_pfn_t current_pfn, temp_pfn;
> > >
> > > if (info->flag_elf_dumpfile)
> > > return FALSE;
> > > @@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
> > >
> > > - 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
> > > }
> > > }
> > >
> > > - consuming_pfn = start_pfn;
> > > - index = -1;
> > > + end_count = 0;
> > > + while (1) {
> > > + consuming = 0;
> > > + check_count = 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.
> > > + */
> > > + 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;
> > > + check_count++;
> > > + consuming = i;
> > > + current_pfn = temp_pfn;
> > > + }
> > > +
> > > + /*
> > > + * If all the threads have reached the end, we will finish writing.
> > > + */
> > > + if (end_count >= info->num_threads)
> > > + goto finish;
> > > +
> > > + /*
> > > + * Since it has the probabilty that there is no page_flag_buf being ready,
> > > + * we should recheck if it happens.
> > > + */
> > > + if (check_count == 0)
> > > + continue;
> > > +
> > > + /*
> > > + * 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;
> > > + }
> > >
> > > - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
> > > }
> > > }
> > >
> > > - if (page_data_buf != NULL) {
> > > - for (i = 0; i < page_data_num; i++) {
> > > - pthread_mutex_destroy(&page_data_buf[i].mutex);
> > > - }
> > > - }
> > > -
> > > 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 +7631,7 @@ 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);
> > >
> > > /*
> > > diff --git a/makedumpfile.h b/makedumpfile.h
> > > index e0b5bbf..5865827 100644
> > > --- a/makedumpfile.h
> > > +++ b/makedumpfile.h
> > > @@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
> > > #define PAGE_DATA_NUM (50)
> > > #define WAIT_TIME (60 * 10)
> > > #define PTHREAD_FAIL ((void *)-2)
> > > -#define NUM_BUFFERS (50)
> > > +#define NUM_BUFFERS (20)
> > >
> > > struct mmap_cache {
> > > char *mmap_buf;
> > > @@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
> > > pthread_t **threads;
> > > struct thread_args *kdump_thread_args;
> > > struct page_data *page_data_buf;
> > > + struct page_flag **page_flag_buf;
> > > 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
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > 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
>
> _______________________________________________
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_______________________________________________
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 7:36 ` Minoru Usui
2016-03-07 8:16 ` Minoru Usui
@ 2016-03-07 8:22 ` "Zhou, Wenjian/周文?"
2016-03-07 8:43 ` "Zhou, Wenjian/周文剑"
1 sibling, 1 reply; 13+ messages in thread
From: "Zhou, Wenjian/周文?" @ 2016-03-07 8:22 UTC (permalink / raw)
To: Minoru Usui; +Cc: Minfei Huang, kexec@lists.infradead.org
On 03/07/2016 03:36 PM, Minoru Usui wrote:
> Hi, Minfei, Zhou
>
>> -----Original Message-----
>> From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of Minfei Huang
>> Sent: Monday, March 07, 2016 4:05 PM
>> To: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
>> Cc: kexec@lists.infradead.org
>> Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
>>
>> Hi, Wenjian.
>>
>> Since your patch applied Minoru Usui's draft patch, I have vierified it.
>> And it works well under 4T memory.
>>
>> applied makedumpfile with option -d 31
>> real 3m48.681s
>>
>> applied makedumpfile with option -d 31 --num-threads 32
>> real 3m3.533s
>>
>> original makedumpfile with option -d 31
>> real 3m57.163s
>>
>> Now with or without option --num-thread, it takes almost same time.
>
> Thank you for your test on big memory machine.
> I am relieved to see your test results.
>
> Zhou, my patch may not be sophisticated,
> but getting mutex logic is robust, it works well and its performance is not bad.
> I think it reaches the goal of the original purpose.
> I understand you don't like getting mutex, but if you are debugging now, could you apply my approach?
>
> Thanks,
> Minoru Usui
>
>
Hi Minoru,
I have test your patch since you post.
I can get a failure easily.
If you run it several times, the dumpfile it produces may be different from the correct one.
+ info->current_pfn = pfn + 1;
+ pthread_mutex_unlock(&info->current_pfn_mutex);
+ page_flag_buf->pfn = pfn;
+ page_flag_buf->ready = FLAG_FILLING;
The above code should be changed to the following:
+ info->current_pfn = pfn + 1;
+ page_flag_buf->pfn = pfn;
+ page_flag_buf->ready = FLAG_FILLING;
+ pthread_mutex_unlock(&info->current_pfn_mutex);
I haven't run your code with the bug fixed.
I'll try now.
By the way, with my patch v3, I can't get an error dumpfile until run it by 5000 times.
--
Thanks
Zhou
>> Thanks
>> Minfei
>>
>> On 03/04/16 at 04:35pm, Zhou Wenjian wrote:
>>> 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 | 300 +++++++++++++++++++++++++++++++++++----------------------
>>> makedumpfile.h | 33 ++++---
>>> 2 files changed, 203 insertions(+), 130 deletions(-)
>>>
>>> diff --git a/makedumpfile.c b/makedumpfile.c
>>> index fa0b779..d75f7f7 100644
>>> --- a/makedumpfile.c
>>> +++ b/makedumpfile.c
>>> @@ -3483,7 +3483,8 @@ initial_for_parallel()
>>> 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);
>>>
>>> @@ -3560,10 +3561,16 @@ initial_for_parallel()
>>>
>>> limit_size = (get_free_memory_size()
>>> - MAP_REGION * info->num_threads) * 0.6;
>>> + if (limit_size < 0) {
>>> + MSG("Free memory is not enough for multi-threads\n");
>>> + return FALSE;
>>> + }
>>>
>>> page_data_num = limit_size / page_data_buf_size;
>>> + info->num_buffers = 3 * info->num_threads;
>>>
>>> - info->num_buffers = MIN(NUM_BUFFERS, page_data_num);
>>> + info->num_buffers = MAX(info->num_buffers, NUM_BUFFERS);
>>> + info->num_buffers = MIN(info->num_buffers, page_data_num);
>>>
>>> DEBUG_MSG("Number of struct page_data for produce/consume: %d\n",
>>> info->num_buffers);
>>> @@ -3588,6 +3595,36 @@ 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 < NUM_BUFFERS; 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 +3649,8 @@ 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 +3693,19 @@ 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 < NUM_BUFFERS; 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 +7126,11 @@ 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 +7176,48 @@ 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)
>>> - continue;
>>> -
>>> - if (page_data_buf[index].ready != 0)
>>> + if (page_flag_buf->ready == FLAG_READY)
>>> continue;
>>>
>>> - pthread_mutex_lock(&page_data_buf[index].mutex);
>>> -
>>> - if (page_data_buf[index].ready != 0)
>>> - goto unlock;
>>> + /* 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;
>>>
>>> - buf_ready = TRUE;
>>> + page_flag_buf->pfn = pfn;
>>> + page_flag_buf->ready = FLAG_FILLING;
>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>>>
>>> - page_data_buf[index].pfn = pfn;
>>> - page_data_buf[index].ready = 1;
>>>
>>> - 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 +7230,11 @@ 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.
>>> @@ -7210,6 +7262,7 @@ kdump_thread_function_cyclic(void *arg) {
>>> page_data_buf[index].flags =
>>> DUMP_DH_COMPRESSED_LZO;
>>> page_data_buf[index].size = size_out;
>>> +
>>> memcpy(page_data_buf[index].buf, buf_out, size_out);
>>> #endif
>>> #ifdef USESNAPPY
>>> @@ -7232,12 +7285,14 @@ 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 +7320,15 @@ 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, check_count;
>>> + mdf_pfn_t current_pfn, temp_pfn;
>>>
>>> if (info->flag_elf_dumpfile)
>>> return FALSE;
>>> @@ -7284,13 +7340,6 @@ 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 +7363,22 @@ 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);
>>>
>>> - 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 +7391,94 @@ write_kdump_pages_parallel_cyclic(struct cache_data *cd_header,
>>> }
>>> }
>>>
>>> - consuming_pfn = start_pfn;
>>> - index = -1;
>>> + end_count = 0;
>>> + while (1) {
>>> + consuming = 0;
>>> + check_count = 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.
>>> + */
>>> + 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;
>>> + check_count++;
>>> + consuming = i;
>>> + current_pfn = temp_pfn;
>>> + }
>>> +
>>> + /*
>>> + * If all the threads have reached the end, we will finish writing.
>>> + */
>>> + if (end_count >= info->num_threads)
>>> + goto finish;
>>> +
>>> + /*
>>> + * Since it has the probabilty that there is no page_flag_buf being ready,
>>> + * we should recheck if it happens.
>>> + */
>>> + if (check_count == 0)
>>> + continue;
>>> +
>>> + /*
>>> + * 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;
>>> + }
>>>
>>> - /* 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 (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 +7494,12 @@ 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 +7537,8 @@ out:
>>> }
>>> }
>>>
>>> - if (page_data_buf != NULL) {
>>> - for (i = 0; i < page_data_num; i++) {
>>> - pthread_mutex_destroy(&page_data_buf[i].mutex);
>>> - }
>>> - }
>>> -
>>> 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 +7631,7 @@ 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);
>>>
>>> /*
>>> diff --git a/makedumpfile.h b/makedumpfile.h
>>> index e0b5bbf..5865827 100644
>>> --- a/makedumpfile.h
>>> +++ b/makedumpfile.h
>>> @@ -977,7 +977,7 @@ typedef unsigned long long int ulonglong;
>>> #define PAGE_DATA_NUM (50)
>>> #define WAIT_TIME (60 * 10)
>>> #define PTHREAD_FAIL ((void *)-2)
>>> -#define NUM_BUFFERS (50)
>>> +#define NUM_BUFFERS (20)
>>>
>>> struct mmap_cache {
>>> char *mmap_buf;
>>> @@ -985,28 +985,33 @@ 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 +1300,11 @@ struct DumpInfo {
>>> pthread_t **threads;
>>> struct thread_args *kdump_thread_args;
>>> struct page_data *page_data_buf;
>>> + struct page_flag **page_flag_buf;
>>> 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
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> 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
_______________________________________________
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 8:16 ` Minoru Usui
@ 2016-03-07 8:39 ` Minfei Huang
2016-03-07 8:46 ` "Zhou, Wenjian/周文剑"
0 siblings, 1 reply; 13+ messages in thread
From: Minfei Huang @ 2016-03-07 8:39 UTC (permalink / raw)
To: Minoru Usui; +Cc: Zhou Wenjian, kexec@lists.infradead.org
On 03/07/16 at 08:16am, Minoru Usui wrote:
> Hi, Minfei
> > >
> > > Hi, Wenjian.
> > >
> > > Since your patch applied Minoru Usui's draft patch, I have vierified it.
> > > And it works well under 4T memory.
> > >
> > > applied makedumpfile with option -d 31
> > > real 3m48.681s
> > >
> > > applied makedumpfile with option -d 31 --num-threads 32
> > > real 3m3.533s
> > >
> > > original makedumpfile with option -d 31
> > > real 3m57.163s
> > >
> > > Now with or without option --num-thread, it takes almost same time.
> >
> > Thank you for your test on big memory machine.
> > I am relieved to see your test results.
>
> I'm sorry, I may be misunderstood.
> Is above result is Zhou's v3 patch or v2 + my patch?
I have applied Zhou's v3 patch.
>
> If above result is Zhou's v3 patch, could you test v2 + my patch?
Your patch fails to be applied based on Zhou's v2 patch. There is a rej
file to be generated during applying.
Thanks
Minfei
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 8:22 ` "Zhou, Wenjian/周文?"
@ 2016-03-07 8:43 ` "Zhou, Wenjian/周文剑"
2016-03-07 8:52 ` Minoru Usui
0 siblings, 1 reply; 13+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-03-07 8:43 UTC (permalink / raw)
To: Minoru Usui; +Cc: Minfei Huang, kexec@lists.infradead.org
Hi Minoru,
I got two error dumpfiles by running it less than 100 times.
--
Thanks
Zhou
On 03/07/2016 04:22 PM, "Zhou, Wenjian/周文?" wrote:
> Hi Minoru,
>
> I have test your patch since you post.
> I can get a failure easily.
> If you run it several times, the dumpfile it produces may be different from the correct one.
>
> + info->current_pfn = pfn + 1;
> + pthread_mutex_unlock(&info->current_pfn_mutex);
> + page_flag_buf->pfn = pfn;
> + page_flag_buf->ready = FLAG_FILLING;
> The above code should be changed to the following:
>
> + info->current_pfn = pfn + 1;
> + page_flag_buf->pfn = pfn;
> + page_flag_buf->ready = FLAG_FILLING;
> + pthread_mutex_unlock(&info->current_pfn_mutex);
>
> I haven't run your code with the bug fixed.
> I'll try now.
>
> By the way, with my patch v3, I can't get an error dumpfile until run it by 5000 times.
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 8:39 ` Minfei Huang
@ 2016-03-07 8:46 ` "Zhou, Wenjian/周文剑"
0 siblings, 0 replies; 13+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-03-07 8:46 UTC (permalink / raw)
To: Minoru Usui; +Cc: Minfei Huang, kexec@lists.infradead.org
Hi,
I did the performance test.
v2 + Minoru's patch and v3 almost have the same performance in -d 31.
--
Thanks
Zhou
On 03/07/2016 04:39 PM, Minfei Huang wrote:
> On 03/07/16 at 08:16am, Minoru Usui wrote:
>> Hi, Minfei
>>>>
>>>> Hi, Wenjian.
>>>>
>>>> Since your patch applied Minoru Usui's draft patch, I have vierified it.
>>>> And it works well under 4T memory.
>>>>
>>>> applied makedumpfile with option -d 31
>>>> real 3m48.681s
>>>>
>>>> applied makedumpfile with option -d 31 --num-threads 32
>>>> real 3m3.533s
>>>>
>>>> original makedumpfile with option -d 31
>>>> real 3m57.163s
>>>>
>>>> Now with or without option --num-thread, it takes almost same time.
>>>
>>> Thank you for your test on big memory machine.
>>> I am relieved to see your test results.
>>
>> I'm sorry, I may be misunderstood.
>> Is above result is Zhou's v3 patch or v2 + my patch?
>
> I have applied Zhou's v3 patch.
>
>>
>> If above result is Zhou's v3 patch, could you test v2 + my patch?
>
> Your patch fails to be applied based on Zhou's v2 patch. There is a rej
> file to be generated during applying.
>
> Thanks
> Minfei
>
>
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 13+ messages in thread
* RE: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 8:43 ` "Zhou, Wenjian/周文剑"
@ 2016-03-07 8:52 ` Minoru Usui
2016-03-07 9:03 ` "Zhou, Wenjian/周文剑"
0 siblings, 1 reply; 13+ messages in thread
From: Minoru Usui @ 2016-03-07 8:52 UTC (permalink / raw)
To: "Zhou, Wenjian/周文剑"
Cc: Minfei Huang, kexec@lists.infradead.org
Hi, Zhou
> -----Original Message-----
> From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of "Zhou, Wenjian/周文?"
> Sent: Monday, March 07, 2016 5:43 PM
> To: Usui Minoru(碓井 成) <min-usui@ti.jp.nec.com>
> Cc: Minfei Huang <mhuang@redhat.com>; kexec@lists.infradead.org
> Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
>
> Hi Minoru,
>
> I got two error dumpfiles by running it less than 100 times.
Oh, I'm sorry.
Thank you for your test.
I'm waiting for your v4 patch.
Thanks
Minoru Usui
> --
> Thanks
> Zhou
>
> On 03/07/2016 04:22 PM, "Zhou, Wenjian/周文?" wrote:
> > Hi Minoru,
> >
> > I have test your patch since you post.
> > I can get a failure easily.
> > If you run it several times, the dumpfile it produces may be different from the correct one.
> >
> > + info->current_pfn = pfn + 1;
> > + pthread_mutex_unlock(&info->current_pfn_mutex);
> > + page_flag_buf->pfn = pfn;
> > + page_flag_buf->ready = FLAG_FILLING;
> > The above code should be changed to the following:
> >
> > + info->current_pfn = pfn + 1;
> > + page_flag_buf->pfn = pfn;
> > + page_flag_buf->ready = FLAG_FILLING;
> > + pthread_mutex_unlock(&info->current_pfn_mutex);
> >
> > I haven't run your code with the bug fixed.
> > I'll try now.
> >
> > By the way, with my patch v3, I can't get an error dumpfile until run it by 5000 times.
>
>
>
> _______________________________________________
> 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] 13+ messages in thread
* Re: [PATCH v3] Improve the performance of --num-threads -d 31
2016-03-07 8:52 ` Minoru Usui
@ 2016-03-07 9:03 ` "Zhou, Wenjian/周文剑"
0 siblings, 0 replies; 13+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2016-03-07 9:03 UTC (permalink / raw)
To: Minoru Usui; +Cc: Minfei Huang, kexec@lists.infradead.org
Hi Minoru,
I guess if you change the part of locking page_data_buf to the following,
it will be more correct.
But I'm not sure if you will get the same problem as which in my patch v3.
+ 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);
--
Thanks
Zhou
On 03/07/2016 04:52 PM, Minoru Usui wrote:
> Hi, Zhou
>
>> -----Original Message-----
>> From: kexec [mailto:kexec-bounces@lists.infradead.org] On Behalf Of "Zhou, Wenjian/周文?"
>> Sent: Monday, March 07, 2016 5:43 PM
>> To: Usui Minoru(碓井 成) <min-usui@ti.jp.nec.com>
>> Cc: Minfei Huang <mhuang@redhat.com>; kexec@lists.infradead.org
>> Subject: Re: [PATCH v3] Improve the performance of --num-threads -d 31
>>
>> Hi Minoru,
>>
>> I got two error dumpfiles by running it less than 100 times.
>
> Oh, I'm sorry.
> Thank you for your test.
>
> I'm waiting for your v4 patch.
>
> Thanks
> Minoru Usui
>
>
>
>> --
>> Thanks
>> Zhou
>>
>> On 03/07/2016 04:22 PM, "Zhou, Wenjian/周文?" wrote:
>>> Hi Minoru,
>>>
>>> I have test your patch since you post.
>>> I can get a failure easily.
>>> If you run it several times, the dumpfile it produces may be different from the correct one.
>>>
>>> + info->current_pfn = pfn + 1;
>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>>> + page_flag_buf->pfn = pfn;
>>> + page_flag_buf->ready = FLAG_FILLING;
>>> The above code should be changed to the following:
>>>
>>> + info->current_pfn = pfn + 1;
>>> + page_flag_buf->pfn = pfn;
>>> + page_flag_buf->ready = FLAG_FILLING;
>>> + pthread_mutex_unlock(&info->current_pfn_mutex);
>>>
>>> I haven't run your code with the bug fixed.
>>> I'll try now.
>>>
>>> By the way, with my patch v3, I can't get an error dumpfile until run it by 5000 times.
>>
>>
>>
>> _______________________________________________
>> 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] 13+ messages in thread
end of thread, other threads:[~2016-03-07 9:05 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-03-04 8:35 [PATCH v3] Improve the performance of --num-threads -d 31 Zhou Wenjian
2016-03-04 9:07 ` "Zhou, Wenjian/周文剑"
2016-03-07 0:17 ` "Zhou, Wenjian/周文剑"
2016-03-07 5:53 ` Minfei Huang
2016-03-07 7:04 ` Minfei Huang
2016-03-07 7:36 ` Minoru Usui
2016-03-07 8:16 ` Minoru Usui
2016-03-07 8:39 ` Minfei Huang
2016-03-07 8:46 ` "Zhou, Wenjian/周文剑"
2016-03-07 8:22 ` "Zhou, Wenjian/周文?"
2016-03-07 8:43 ` "Zhou, Wenjian/周文剑"
2016-03-07 8:52 ` Minoru Usui
2016-03-07 9:03 ` "Zhou, Wenjian/周文剑"
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