* [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-23 19:31 ` Geert Uytterhoeven
2013-03-19 9:25 ` [PATCH v4 2/8] staging: zcache: zero-filled pages awareness Wanpeng Li
` (7 subsequent siblings)
8 siblings, 1 reply; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Introduce zero-filled pages handler to capture and handle zero pages.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/zcache-main.c | 26 ++++++++++++++++++++++++++
1 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 328898e..d73dd4b 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -460,6 +460,32 @@ static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
kmem_cache_free(zcache_obj_cache, obj);
}
+static bool page_is_zero_filled(void *ptr)
+{
+ unsigned int pos;
+ unsigned long *page;
+
+ page = (unsigned long *)ptr;
+
+ for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++) {
+ if (page[pos])
+ return false;
+ }
+
+ return true;
+}
+
+static void handle_zero_filled_page(void *page)
+{
+ void *user_mem;
+
+ user_mem = kmap_atomic(page);
+ memset(user_mem, 0, PAGE_SIZE);
+ kunmap_atomic(user_mem);
+
+ flush_dcache_page(page);
+}
+
static struct tmem_hostops zcache_hostops = {
.obj_alloc = zcache_obj_alloc,
.obj_free = zcache_obj_free,
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler
2013-03-19 9:25 ` [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler Wanpeng Li
@ 2013-03-23 19:31 ` Geert Uytterhoeven
0 siblings, 0 replies; 14+ messages in thread
From: Geert Uytterhoeven @ 2013-03-23 19:31 UTC (permalink / raw)
To: Wanpeng Li
Cc: Greg Kroah-Hartman, Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Linux-Next
On Tue, Mar 19, 2013 at 10:25 AM, Wanpeng Li <liwanp@linux.vnet.ibm.com> wrote:
> Introduce zero-filled pages handler to capture and handle zero pages.
>
> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
> ---
> drivers/staging/zcache/zcache-main.c | 26 ++++++++++++++++++++++++++
> 1 files changed, 26 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
> index 328898e..d73dd4b 100644
> --- a/drivers/staging/zcache/zcache-main.c
> +++ b/drivers/staging/zcache/zcache-main.c
> +static void handle_zero_filled_page(void *page)
> +{
> + void *user_mem;
> +
> + user_mem = kmap_atomic(page);
kmap_atomic() takes a "struct page *", not a "void *".
> + memset(user_mem, 0, PAGE_SIZE);
> + kunmap_atomic(user_mem);
> +
> + flush_dcache_page(page);
While flush_dcache_page() is a no-op on many architectures, it also
takes a "struct page *", not a "void *":
m68k/allmodconfig:
drivers/staging/zcache/zcache-main.c:309:2: error: request for member
'virtual' in something not a structure or union
Cfr. http://kisskb.ellerman.id.au/kisskb/buildresult/8433711/
> +}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4 2/8] staging: zcache: zero-filled pages awareness
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-20 10:30 ` Bob Liu
2013-03-19 9:25 ` [PATCH v4 3/8] staging: zcache: handle zcache_[eph|pers]_zpages for zero-filled page Wanpeng Li
` (6 subsequent siblings)
8 siblings, 1 reply; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Compression of zero-filled pages can unneccessarily cause internal
fragmentation, and thus waste memory. This special case can be
optimized.
This patch captures zero-filled pages, and marks their corresponding
zcache backing page entry as zero-filled. Whenever such zero-filled
page is retrieved, we fill the page frame with zero.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/zcache-main.c | 80 ++++++++++++++++++++++++++++-----
1 files changed, 68 insertions(+), 12 deletions(-)
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 86ead8d..050a99f 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -61,6 +61,12 @@ static inline void frontswap_tmem_exclusive_gets(bool b)
}
#endif
+/*
+ * mark pampd to special value in order that later
+ * retrieve will identify zero-filled pages
+ */
+#define ZERO_FILLED 0x2
+
/* enable (or fix code) when Seth's patches are accepted upstream */
#define zcache_writeback_enabled 0
@@ -277,17 +283,23 @@ static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
kmem_cache_free(zcache_obj_cache, obj);
}
-static bool page_is_zero_filled(void *ptr)
+/*
+ * Compressing zero-filled pages will waste memory and introduce
+ * serious fragmentation, skip it to avoid overhead.
+ */
+static bool page_is_zero_filled(struct page *p)
{
unsigned int pos;
- unsigned long *page;
-
- page = (unsigned long *)ptr;
+ char *page;
+ page = kmap_atomic(p);
for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++) {
- if (page[pos])
+ if (page[pos]) {
+ kunmap_atomic(page);
return false;
+ }
}
+ kunmap_atomic(page);
return true;
}
@@ -355,8 +367,15 @@ static void *zcache_pampd_eph_create(char *data, size_t size, bool raw,
{
void *pampd = NULL, *cdata = data;
unsigned clen = size;
+ bool zero_filled = false;
struct page *page = (struct page *)(data), *newpage;
+ if (page_is_zero_filled(page)) {
+ clen = 0;
+ zero_filled = true;
+ goto got_pampd;
+ }
+
if (!raw) {
zcache_compress(page, &cdata, &clen);
if (clen > zbud_max_buddy_size()) {
@@ -396,6 +415,8 @@ got_pampd:
inc_zcache_eph_zpages();
if (ramster_enabled && raw)
ramster_count_foreign_pages(true, 1);
+ if (zero_filled)
+ pampd = (void *)ZERO_FILLED;
out:
return pampd;
}
@@ -405,6 +426,7 @@ static void *zcache_pampd_pers_create(char *data, size_t size, bool raw,
{
void *pampd = NULL, *cdata = data;
unsigned clen = size;
+ bool zero_filled = false;
struct page *page = (struct page *)(data), *newpage;
unsigned long zbud_mean_zsize;
unsigned long curr_pers_zpages, total_zsize;
@@ -413,6 +435,13 @@ static void *zcache_pampd_pers_create(char *data, size_t size, bool raw,
BUG_ON(!ramster_enabled);
goto create_pampd;
}
+
+ if (page_is_zero_filled(page)) {
+ clen = 0;
+ zero_filled = true;
+ goto got_pampd;
+ }
+
curr_pers_zpages = zcache_pers_zpages;
/* FIXME CONFIG_RAMSTER... subtract atomic remote_pers_pages here? */
if (!raw)
@@ -470,6 +499,8 @@ got_pampd:
inc_zcache_pers_zbytes(clen);
if (ramster_enabled && raw)
ramster_count_foreign_pages(false, 1);
+ if (zero_filled)
+ pampd = (void *)ZERO_FILLED;
out:
return pampd;
}
@@ -531,7 +562,8 @@ out:
*/
void zcache_pampd_create_finish(void *pampd, bool eph)
{
- zbud_create_finish((struct zbudref *)pampd, eph);
+ if (pampd != (void *)ZERO_FILLED)
+ zbud_create_finish((struct zbudref *)pampd, eph);
}
/*
@@ -576,6 +608,14 @@ static int zcache_pampd_get_data(char *data, size_t *sizep, bool raw,
BUG_ON(preemptible());
BUG_ON(eph); /* fix later if shared pools get implemented */
BUG_ON(pampd_is_remote(pampd));
+
+ if (pampd == (void *)ZERO_FILLED) {
+ handle_zero_filled_page(data);
+ if (!raw)
+ *sizep = PAGE_SIZE;
+ return 0;
+ }
+
if (raw)
ret = zbud_copy_from_zbud(data, (struct zbudref *)pampd,
sizep, eph);
@@ -596,13 +636,22 @@ static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
void *pampd, struct tmem_pool *pool,
struct tmem_oid *oid, uint32_t index)
{
- int ret;
- bool eph = !is_persistent(pool);
+ int ret = 0;
+ bool eph = !is_persistent(pool), zero_filled = false;
struct page *page = NULL;
unsigned int zsize, zpages;
BUG_ON(preemptible());
BUG_ON(pampd_is_remote(pampd));
+
+ if (pampd == (void *)ZERO_FILLED) {
+ handle_zero_filled_page(data);
+ zero_filled = true;
+ if (!raw)
+ *sizep = PAGE_SIZE;
+ goto zero_fill;
+ }
+
if (raw)
ret = zbud_copy_from_zbud(data, (struct zbudref *)pampd,
sizep, eph);
@@ -614,6 +663,7 @@ static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
}
page = zbud_free_and_delist((struct zbudref *)pampd, eph,
&zsize, &zpages);
+zero_fill:
if (eph) {
if (page)
dec_zcache_eph_pageframes();
@@ -627,7 +677,7 @@ static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
}
if (!is_local_client(pool->client))
ramster_count_foreign_pages(eph, -1);
- if (page)
+ if (page && !zero_filled)
zcache_free_page(page);
return ret;
}
@@ -641,16 +691,22 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
{
struct page *page = NULL;
unsigned int zsize, zpages;
+ bool zero_filled = false;
BUG_ON(preemptible());
- if (pampd_is_remote(pampd)) {
+
+ if (pampd == (void *)ZERO_FILLED)
+ zero_filled = true;
+
+ if (pampd_is_remote(pampd) && !zero_filled) {
BUG_ON(!ramster_enabled);
pampd = ramster_pampd_free(pampd, pool, oid, index, acct);
if (pampd == NULL)
return;
}
if (is_ephemeral(pool)) {
- page = zbud_free_and_delist((struct zbudref *)pampd,
+ if (!zero_filled)
+ page = zbud_free_and_delist((struct zbudref *)pampd,
true, &zsize, &zpages);
if (page)
dec_zcache_eph_pageframes();
@@ -667,7 +723,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
}
if (!is_local_client(pool->client))
ramster_count_foreign_pages(is_ephemeral(pool), -1);
- if (page)
+ if (page && !zero_filled)
zcache_free_page(page);
}
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v4 2/8] staging: zcache: zero-filled pages awareness
2013-03-19 9:25 ` [PATCH v4 2/8] staging: zcache: zero-filled pages awareness Wanpeng Li
@ 2013-03-20 10:30 ` Bob Liu
2013-03-20 10:43 ` Wanpeng Li
2013-03-20 10:43 ` Wanpeng Li
0 siblings, 2 replies; 14+ messages in thread
From: Bob Liu @ 2013-03-20 10:30 UTC (permalink / raw)
To: Wanpeng Li
Cc: Greg Kroah-Hartman, Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel
> @@ -641,16 +691,22 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
> {
> struct page *page = NULL;
> unsigned int zsize, zpages;
> + bool zero_filled = false;
>
> BUG_ON(preemptible());
> - if (pampd_is_remote(pampd)) {
> +
> + if (pampd == (void *)ZERO_FILLED)
> + zero_filled = true;
> +
> + if (pampd_is_remote(pampd) && !zero_filled) {
> BUG_ON(!ramster_enabled);
> pampd = ramster_pampd_free(pampd, pool, oid, index, acct);
> if (pampd == NULL)
> return;
> }
> if (is_ephemeral(pool)) {
> - page = zbud_free_and_delist((struct zbudref *)pampd,
> + if (!zero_filled)
> + page = zbud_free_and_delist((struct zbudref *)pampd,
> true, &zsize, &zpages);
This check should also apply for !is_ephemeral(pool).
> if (page)
> dec_zcache_eph_pageframes();
> @@ -667,7 +723,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
> }
> if (!is_local_client(pool->client))
> ramster_count_foreign_pages(is_ephemeral(pool), -1);
> - if (page)
> + if (page && !zero_filled)
> zcache_free_page(page);
> }
>
>
--
Regards,
-Bob
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v4 2/8] staging: zcache: zero-filled pages awareness
2013-03-20 10:30 ` Bob Liu
@ 2013-03-20 10:43 ` Wanpeng Li
2013-03-20 10:43 ` Wanpeng Li
1 sibling, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-20 10:43 UTC (permalink / raw)
To: Bob Liu
Cc: Greg Kroah-Hartman, Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel
On Wed, Mar 20, 2013 at 06:30:38PM +0800, Bob Liu wrote:
>
>> @@ -641,16 +691,22 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
>> {
>> struct page *page = NULL;
>> unsigned int zsize, zpages;
>> + bool zero_filled = false;
>>
>> BUG_ON(preemptible());
>> - if (pampd_is_remote(pampd)) {
>> +
>> + if (pampd == (void *)ZERO_FILLED)
>> + zero_filled = true;
>> +
>> + if (pampd_is_remote(pampd) && !zero_filled) {
>> BUG_ON(!ramster_enabled);
>> pampd = ramster_pampd_free(pampd, pool, oid, index, acct);
>> if (pampd == NULL)
>> return;
>> }
>> if (is_ephemeral(pool)) {
>> - page = zbud_free_and_delist((struct zbudref *)pampd,
>> + if (!zero_filled)
>> + page = zbud_free_and_delist((struct zbudref *)pampd,
>> true, &zsize, &zpages);
>
>This check should also apply for !is_ephemeral(pool).
Good catch, fixed.
>
>> if (page)
>> dec_zcache_eph_pageframes();
>> @@ -667,7 +723,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
>> }
>> if (!is_local_client(pool->client))
>> ramster_count_foreign_pages(is_ephemeral(pool), -1);
>> - if (page)
>> + if (page && !zero_filled)
>> zcache_free_page(page);
>> }
>>
>>
>
>--
>Regards,
>-Bob
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v4 2/8] staging: zcache: zero-filled pages awareness
2013-03-20 10:30 ` Bob Liu
2013-03-20 10:43 ` Wanpeng Li
@ 2013-03-20 10:43 ` Wanpeng Li
1 sibling, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-20 10:43 UTC (permalink / raw)
To: Bob Liu
Cc: Greg Kroah-Hartman, Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel
On Wed, Mar 20, 2013 at 06:30:38PM +0800, Bob Liu wrote:
>
>> @@ -641,16 +691,22 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
>> {
>> struct page *page = NULL;
>> unsigned int zsize, zpages;
>> + bool zero_filled = false;
>>
>> BUG_ON(preemptible());
>> - if (pampd_is_remote(pampd)) {
>> +
>> + if (pampd == (void *)ZERO_FILLED)
>> + zero_filled = true;
>> +
>> + if (pampd_is_remote(pampd) && !zero_filled) {
>> BUG_ON(!ramster_enabled);
>> pampd = ramster_pampd_free(pampd, pool, oid, index, acct);
>> if (pampd == NULL)
>> return;
>> }
>> if (is_ephemeral(pool)) {
>> - page = zbud_free_and_delist((struct zbudref *)pampd,
>> + if (!zero_filled)
>> + page = zbud_free_and_delist((struct zbudref *)pampd,
>> true, &zsize, &zpages);
>
>This check should also apply for !is_ephemeral(pool).
Good catch, fixed.
>
>> if (page)
>> dec_zcache_eph_pageframes();
>> @@ -667,7 +723,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
>> }
>> if (!is_local_client(pool->client))
>> ramster_count_foreign_pages(is_ephemeral(pool), -1);
>> - if (page)
>> + if (page && !zero_filled)
>> zcache_free_page(page);
>> }
>>
>>
>
>--
>Regards,
>-Bob
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v4 3/8] staging: zcache: handle zcache_[eph|pers]_zpages for zero-filled page
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 1/8] staging: zcache: introduce zero-filled pages handler Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 2/8] staging: zcache: zero-filled pages awareness Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 4/8] staging: zcache: fix pers_pageframes|_max aren't exported in debugfs Wanpeng Li
` (5 subsequent siblings)
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Increment/decrement zcache_[eph|pers]_zpages for zero-filled pages,
the main point of the counters for zpages and pageframes is to be
able to calculate density == zpages/pageframes. A zero-filled page
becomes a zpage that "compresses" to zero bytes and, as a result,
requires zero pageframes for storage. So the zpages counter should
be increased but the pageframes counter should not.
[Dan Magenheimer <dan.magenheimer@oracle.com>: patch description]
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/zcache-main.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 050a99f..892e97e 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -647,6 +647,8 @@ static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
if (pampd == (void *)ZERO_FILLED) {
handle_zero_filled_page(data);
zero_filled = true;
+ zsize = 0;
+ zpages = 1;
if (!raw)
*sizep = PAGE_SIZE;
goto zero_fill;
@@ -695,8 +697,11 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
BUG_ON(preemptible());
- if (pampd == (void *)ZERO_FILLED)
+ if (pampd == (void *)ZERO_FILLED) {
zero_filled = true;
+ zsize = 0;
+ zpages = 1;
+ }
if (pampd_is_remote(pampd) && !zero_filled) {
BUG_ON(!ramster_enabled);
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 4/8] staging: zcache: fix pers_pageframes|_max aren't exported in debugfs
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (2 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 3/8] staging: zcache: handle zcache_[eph|pers]_zpages for zero-filled page Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 5/8] staging: zcache: fix zcache writeback " Wanpeng Li
` (4 subsequent siblings)
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Before commit 9c0ad59ef ("zcache/debug: Use an array to initialize/use debugfs attributes"),
pers_pageframes|_max are exported in debugfs, but this commit forgot use array export
pers_pageframes|_max. This patch add pers_pageframes|_max back.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/debug.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/drivers/staging/zcache/debug.c b/drivers/staging/zcache/debug.c
index e951c64..254dada 100644
--- a/drivers/staging/zcache/debug.c
+++ b/drivers/staging/zcache/debug.c
@@ -21,6 +21,7 @@ static struct debug_entry {
ATTR(pers_ate_eph), ATTR(pers_ate_eph_failed),
ATTR(evicted_eph_zpages), ATTR(evicted_eph_pageframes),
ATTR(eph_pageframes), ATTR(eph_pageframes_max),
+ ATTR(pers_pageframes), ATTR(pers_pageframes_max),
ATTR(eph_zpages), ATTR(eph_zpages_max),
ATTR(pers_zpages), ATTR(pers_zpages_max),
ATTR(last_active_file_pageframes),
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 5/8] staging: zcache: fix zcache writeback in debugfs
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (3 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 4/8] staging: zcache: fix pers_pageframes|_max aren't exported in debugfs Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 6/8] staging: zcache: fix static variables defined in debug.h but used in mutiple C files Wanpeng Li
` (3 subsequent siblings)
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
commit 9c0ad59ef ("zcache/debug: Use an array to initialize/use debugfs attributes")
use an array to initialize/use debugfs attributes, .name = #x, .val = &zcache_##x.
For zcache writeback, this commit set .name = zcache_outstanding_writeback_pages and
.name = zcache_writtenback_pages seperately, however, corresponding .val =
&zcache_zcache_outstanding_writeback_pages and .val = &zcache_zcache_writtenback_pages,
which are not correct.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/debug.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/zcache/debug.c b/drivers/staging/zcache/debug.c
index 254dada..d2d1fdf 100644
--- a/drivers/staging/zcache/debug.c
+++ b/drivers/staging/zcache/debug.c
@@ -31,8 +31,8 @@ static struct debug_entry {
ATTR(eph_nonactive_puts_ignored),
ATTR(pers_nonactive_puts_ignored),
#ifdef CONFIG_ZCACHE_WRITEBACK
- ATTR(zcache_outstanding_writeback_pages),
- ATTR(zcache_writtenback_pages),
+ ATTR(outstanding_writeback_pages),
+ ATTR(writtenback_pages),
#endif
};
#undef ATTR
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 6/8] staging: zcache: fix static variables defined in debug.h but used in mutiple C files
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (4 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 5/8] staging: zcache: fix zcache writeback " Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 7/8] staging: zcache: introduce zero-filled page stat count Wanpeng Li
` (2 subsequent siblings)
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
After commit 95bdaee214 ("zcache: Move debugfs code out of zcache-main.c file")
be merged, most of knods in zcache debugfs just export zero since these variables
are defined in debug.h but use in multiple C files zcache-main.c and debug.c, in
this case variables can't be treated as shared variables.
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/debug.h | 62 +++++++++++++++++-----------------
drivers/staging/zcache/zcache-main.c | 31 +++++++++++++++++
2 files changed, 62 insertions(+), 31 deletions(-)
diff --git a/drivers/staging/zcache/debug.h b/drivers/staging/zcache/debug.h
index 4bbe49b..8ec82d4 100644
--- a/drivers/staging/zcache/debug.h
+++ b/drivers/staging/zcache/debug.h
@@ -3,9 +3,9 @@
#ifdef CONFIG_ZCACHE_DEBUG
/* we try to keep these statistics SMP-consistent */
-static ssize_t zcache_obj_count;
+extern ssize_t zcache_obj_count;
static atomic_t zcache_obj_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_obj_count_max;
+extern ssize_t zcache_obj_count_max;
static inline void inc_zcache_obj_count(void)
{
zcache_obj_count = atomic_inc_return(&zcache_obj_atomic);
@@ -17,9 +17,9 @@ static inline void dec_zcache_obj_count(void)
zcache_obj_count = atomic_dec_return(&zcache_obj_atomic);
BUG_ON(zcache_obj_count < 0);
};
-static ssize_t zcache_objnode_count;
+extern ssize_t zcache_objnode_count;
static atomic_t zcache_objnode_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_objnode_count_max;
+extern ssize_t zcache_objnode_count_max;
static inline void inc_zcache_objnode_count(void)
{
zcache_objnode_count = atomic_inc_return(&zcache_objnode_atomic);
@@ -31,9 +31,9 @@ static inline void dec_zcache_objnode_count(void)
zcache_objnode_count = atomic_dec_return(&zcache_objnode_atomic);
BUG_ON(zcache_objnode_count < 0);
};
-static u64 zcache_eph_zbytes;
+extern u64 zcache_eph_zbytes;
static atomic_long_t zcache_eph_zbytes_atomic = ATOMIC_INIT(0);
-static u64 zcache_eph_zbytes_max;
+extern u64 zcache_eph_zbytes_max;
static inline void inc_zcache_eph_zbytes(unsigned clen)
{
zcache_eph_zbytes = atomic_long_add_return(clen, &zcache_eph_zbytes_atomic);
@@ -46,7 +46,7 @@ static inline void dec_zcache_eph_zbytes(unsigned zsize)
};
extern u64 zcache_pers_zbytes;
static atomic_long_t zcache_pers_zbytes_atomic = ATOMIC_INIT(0);
-static u64 zcache_pers_zbytes_max;
+extern u64 zcache_pers_zbytes_max;
static inline void inc_zcache_pers_zbytes(unsigned clen)
{
zcache_pers_zbytes = atomic_long_add_return(clen, &zcache_pers_zbytes_atomic);
@@ -59,7 +59,7 @@ static inline void dec_zcache_pers_zbytes(unsigned zsize)
}
extern ssize_t zcache_eph_pageframes;
static atomic_t zcache_eph_pageframes_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_eph_pageframes_max;
+extern ssize_t zcache_eph_pageframes_max;
static inline void inc_zcache_eph_pageframes(void)
{
zcache_eph_pageframes = atomic_inc_return(&zcache_eph_pageframes_atomic);
@@ -72,7 +72,7 @@ static inline void dec_zcache_eph_pageframes(void)
};
extern ssize_t zcache_pers_pageframes;
static atomic_t zcache_pers_pageframes_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_pers_pageframes_max;
+extern ssize_t zcache_pers_pageframes_max;
static inline void inc_zcache_pers_pageframes(void)
{
zcache_pers_pageframes = atomic_inc_return(&zcache_pers_pageframes_atomic);
@@ -83,21 +83,21 @@ static inline void dec_zcache_pers_pageframes(void)
{
zcache_pers_pageframes = atomic_dec_return(&zcache_pers_pageframes_atomic);
}
-static ssize_t zcache_pageframes_alloced;
+extern ssize_t zcache_pageframes_alloced;
static atomic_t zcache_pageframes_alloced_atomic = ATOMIC_INIT(0);
static inline void inc_zcache_pageframes_alloced(void)
{
zcache_pageframes_alloced = atomic_inc_return(&zcache_pageframes_alloced_atomic);
};
-static ssize_t zcache_pageframes_freed;
+extern ssize_t zcache_pageframes_freed;
static atomic_t zcache_pageframes_freed_atomic = ATOMIC_INIT(0);
static inline void inc_zcache_pageframes_freed(void)
{
zcache_pageframes_freed = atomic_inc_return(&zcache_pageframes_freed_atomic);
}
-static ssize_t zcache_eph_zpages;
+extern ssize_t zcache_eph_zpages;
static atomic_t zcache_eph_zpages_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_eph_zpages_max;
+extern ssize_t zcache_eph_zpages_max;
static inline void inc_zcache_eph_zpages(void)
{
zcache_eph_zpages = atomic_inc_return(&zcache_eph_zpages_atomic);
@@ -110,7 +110,7 @@ static inline void dec_zcache_eph_zpages(unsigned zpages)
}
extern ssize_t zcache_pers_zpages;
static atomic_t zcache_pers_zpages_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_pers_zpages_max;
+extern ssize_t zcache_pers_zpages_max;
static inline void inc_zcache_pers_zpages(void)
{
zcache_pers_zpages = atomic_inc_return(&zcache_pers_zpages_atomic);
@@ -130,23 +130,23 @@ static inline unsigned long curr_pageframes_count(void)
atomic_read(&zcache_pers_pageframes_atomic);
};
/* but for the rest of these, counting races are ok */
-static ssize_t zcache_flush_total;
-static ssize_t zcache_flush_found;
-static ssize_t zcache_flobj_total;
-static ssize_t zcache_flobj_found;
-static ssize_t zcache_failed_eph_puts;
-static ssize_t zcache_failed_pers_puts;
-static ssize_t zcache_failed_getfreepages;
-static ssize_t zcache_failed_alloc;
-static ssize_t zcache_put_to_flush;
-static ssize_t zcache_compress_poor;
-static ssize_t zcache_mean_compress_poor;
-static ssize_t zcache_eph_ate_tail;
-static ssize_t zcache_eph_ate_tail_failed;
-static ssize_t zcache_pers_ate_eph;
-static ssize_t zcache_pers_ate_eph_failed;
-static ssize_t zcache_evicted_eph_zpages;
-static ssize_t zcache_evicted_eph_pageframes;
+extern ssize_t zcache_flush_total;
+extern ssize_t zcache_flush_found;
+extern ssize_t zcache_flobj_total;
+extern ssize_t zcache_flobj_found;
+extern ssize_t zcache_failed_eph_puts;
+extern ssize_t zcache_failed_pers_puts;
+extern ssize_t zcache_failed_getfreepages;
+extern ssize_t zcache_failed_alloc;
+extern ssize_t zcache_put_to_flush;
+extern ssize_t zcache_compress_poor;
+extern ssize_t zcache_mean_compress_poor;
+extern ssize_t zcache_eph_ate_tail;
+extern ssize_t zcache_eph_ate_tail_failed;
+extern ssize_t zcache_pers_ate_eph;
+extern ssize_t zcache_pers_ate_eph_failed;
+extern ssize_t zcache_evicted_eph_zpages;
+extern ssize_t zcache_evicted_eph_pageframes;
extern ssize_t zcache_last_active_file_pageframes;
extern ssize_t zcache_last_inactive_file_pageframes;
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 892e97e..d1118f0 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -145,6 +145,37 @@ ssize_t zcache_pers_zpages;
u64 zcache_pers_zbytes;
ssize_t zcache_eph_pageframes;
ssize_t zcache_pers_pageframes;
+ssize_t zcache_obj_count;
+ssize_t zcache_obj_count_max;
+ssize_t zcache_objnode_count;
+ssize_t zcache_objnode_count_max;
+u64 zcache_eph_zbytes;
+u64 zcache_eph_zbytes_max;
+u64 zcache_pers_zbytes_max;
+ssize_t zcache_eph_pageframes_max;
+ssize_t zcache_pers_pageframes_max;
+ssize_t zcache_pageframes_alloced;
+ssize_t zcache_pageframes_freed;
+ssize_t zcache_eph_zpages;
+ssize_t zcache_eph_zpages_max;
+ssize_t zcache_pers_zpages_max;
+ssize_t zcache_flush_total;
+ssize_t zcache_flush_found;
+ssize_t zcache_flobj_total;
+ssize_t zcache_flobj_found;
+ssize_t zcache_failed_eph_puts;
+ssize_t zcache_failed_pers_puts;
+ssize_t zcache_failed_getfreepages;
+ssize_t zcache_failed_alloc;
+ssize_t zcache_put_to_flush;
+ssize_t zcache_compress_poor;
+ssize_t zcache_mean_compress_poor;
+ssize_t zcache_eph_ate_tail;
+ssize_t zcache_eph_ate_tail_failed;
+ssize_t zcache_pers_ate_eph;
+ssize_t zcache_pers_ate_eph_failed;
+ssize_t zcache_evicted_eph_zpages;
+ssize_t zcache_evicted_eph_pageframes;
/* Used by this code. */
ssize_t zcache_last_active_file_pageframes;
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 7/8] staging: zcache: introduce zero-filled page stat count
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (5 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 6/8] staging: zcache: fix static variables defined in debug.h but used in mutiple C files Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 9:25 ` [PATCH v4 8/8] staging: zcache: clean TODO list Wanpeng Li
2013-03-19 23:34 ` [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Ric Mason
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Introduce zero-filled page statistics to monitor the number of
zero-filled pages.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/debug.h | 15 +++++++++++++++
drivers/staging/zcache/zcache-main.c | 5 +++++
2 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/drivers/staging/zcache/debug.h b/drivers/staging/zcache/debug.h
index 8ec82d4..178bf75 100644
--- a/drivers/staging/zcache/debug.h
+++ b/drivers/staging/zcache/debug.h
@@ -122,6 +122,21 @@ static inline void dec_zcache_pers_zpages(unsigned zpages)
zcache_pers_zpages = atomic_sub_return(zpages, &zcache_pers_zpages_atomic);
}
+extern ssize_t zcache_zero_filled_pages;
+static atomic_t zcache_zero_filled_pages_atomic = ATOMIC_INIT(0);
+extern ssize_t zcache_zero_filled_pages_max;
+static inline void inc_zcache_zero_filled_pages(void)
+{
+ zcache_zero_filled_pages = atomic_inc_return(
+ &zcache_zero_filled_pages_atomic);
+ if (zcache_zero_filled_pages > zcache_zero_filled_pages_max)
+ zcache_zero_filled_pages_max = zcache_zero_filled_pages;
+}
+static inline void dec_zcache_zero_filled_pages(void)
+{
+ zcache_zero_filled_pages = atomic_dec_return(
+ &zcache_zero_filled_pages_atomic);
+}
static inline unsigned long curr_pageframes_count(void)
{
return zcache_pageframes_alloced -
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index d1118f0..f8ba619 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -176,6 +176,8 @@ ssize_t zcache_pers_ate_eph;
ssize_t zcache_pers_ate_eph_failed;
ssize_t zcache_evicted_eph_zpages;
ssize_t zcache_evicted_eph_pageframes;
+ssize_t zcache_zero_filled_pages;
+ssize_t zcache_zero_filled_pages_max;
/* Used by this code. */
ssize_t zcache_last_active_file_pageframes;
@@ -404,6 +406,7 @@ static void *zcache_pampd_eph_create(char *data, size_t size, bool raw,
if (page_is_zero_filled(page)) {
clen = 0;
zero_filled = true;
+ inc_zcache_zero_filled_pages();
goto got_pampd;
}
@@ -470,6 +473,7 @@ static void *zcache_pampd_pers_create(char *data, size_t size, bool raw,
if (page_is_zero_filled(page)) {
clen = 0;
zero_filled = true;
+ inc_zcache_zero_filled_pages();
goto got_pampd;
}
@@ -682,6 +686,7 @@ static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
zpages = 1;
if (!raw)
*sizep = PAGE_SIZE;
+ dec_zcache_zero_filled_pages();
goto zero_fill;
}
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v4 8/8] staging: zcache: clean TODO list
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (6 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 7/8] staging: zcache: introduce zero-filled page stat count Wanpeng Li
@ 2013-03-19 9:25 ` Wanpeng Li
2013-03-19 23:34 ` [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Ric Mason
8 siblings, 0 replies; 14+ messages in thread
From: Wanpeng Li @ 2013-03-19 9:25 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel,
Wanpeng Li
Cleanup TODO list since support zero-filled pages more efficiently has
already done by this patchset.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
drivers/staging/zcache/TODO | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/zcache/TODO b/drivers/staging/zcache/TODO
index ec9aa11..d0c18fa 100644
--- a/drivers/staging/zcache/TODO
+++ b/drivers/staging/zcache/TODO
@@ -61,5 +61,4 @@ ZCACHE FUTURE NEW FUNCTIONALITY
A. Support zsmalloc as an alternative high-density allocator
(See https://lkml.org/lkml/2013/1/23/511)
-B. Support zero-filled pages more efficiently
-C. Possibly support three zbuds per pageframe when space allows
+B. Possibly support three zbuds per pageframe when space allows
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently
2013-03-19 9:25 [PATCH v4 0/8] staging: zcache: Support zero-filled pages more efficiently Wanpeng Li
` (7 preceding siblings ...)
2013-03-19 9:25 ` [PATCH v4 8/8] staging: zcache: clean TODO list Wanpeng Li
@ 2013-03-19 23:34 ` Ric Mason
8 siblings, 0 replies; 14+ messages in thread
From: Ric Mason @ 2013-03-19 23:34 UTC (permalink / raw)
To: Wanpeng Li
Cc: Greg Kroah-Hartman, Andrew Morton, Dan Magenheimer, Seth Jennings,
Konrad Rzeszutek Wilk, Minchan Kim, linux-mm, linux-kernel
On 03/19/2013 05:25 PM, Wanpeng Li wrote:
> Hi Greg,
>
> Since you have already merge 1/8, feel free to merge 2/8~8/8, I have already
> rebased against staging-next.
>
> Changelog:
> v3 -> v4:
> * handle duplication in page_is_zero_filled, spotted by Bob
> * fix zcache writeback in dubugfs
> * fix pers_pageframes|_max isn't exported in debugfs
> * fix static variable defined in debug.h but used in multiple C files
> * rebase on Greg's staging-next
> v2 -> v3:
> * increment/decrement zcache_[eph|pers]_zpages for zero-filled pages, spotted by Dan
> * replace "zero" or "zero page" by "zero_filled_page", spotted by Dan
> v1 -> v2:
> * avoid changing tmem.[ch] entirely, spotted by Dan.
> * don't accumulate [eph|pers]pageframe and [eph|pers]zpages for
> zero-filled pages, spotted by Dan
> * cleanup TODO list
> * add Dan Acked-by.
>
> Motivation:
>
> - Seth Jennings points out compress zero-filled pages with LZO(a lossless
> data compression algorithm) will waste memory and result in fragmentation.
> https://lkml.org/lkml/2012/8/14/347
> - Dan Magenheimer add "Support zero-filled pages more efficiently" feature
> in zcache TODO list https://lkml.org/lkml/2013/2/13/503
>
> Design:
>
> - For store page, capture zero-filled pages(evicted clean page cache pages and
> swap pages), but don't compress them, set pampd which store zpage address to
> 0x2(since 0x0 and 0x1 has already been ocuppied) to mark special zero-filled
> case and take advantage of tmem infrastructure to transform handle-tuple(pool
> id, object id, and an index) to a pampd. Twice compress zero-filled pages will
> contribute to one zcache_[eph|pers]_pageframes count accumulated.
> - For load page, traverse tmem hierachical to transform handle-tuple to pampd
> and identify zero-filled case by pampd equal to 0x2 when filesystem reads
> file pages or a page needs to be swapped in, then refill the page to zero
> and return.
>
> Test:
>
> dd if=/dev/zero of=zerofile bs=1MB count=500
> vmtouch -t zerofile
> vmtouch -e zerofile
>
> formula:
> - fragmentation level = (zcache_[eph|pers]_pageframes * PAGE_SIZE - zcache_[eph|pers]_zbytes)
> * 100 / (zcache_[eph|pers]_pageframes * PAGE_SIZE)
> - memory zcache occupy = zcache_[eph|pers]_zbytes
>
> Result:
>
> without zero-filled awareness:
> - fragmentation level: 98%
> - memory zcache occupy: 238MB
> with zero-filled awareness:
> - fragmentation level: 0%
> - memory zcache occupy: 0MB
>
> Wanpeng Li (8):
> introduce zero filled pages handler
> zero-filled pages awareness
> handle zcache_[eph|pers]_pages for zero-filled page
> fix pers_pageframes|_max aren't exported in debugfs
> fix zcache writeback in debugfs
> fix static variables are defined in debug.h but use in multiple C files
> introduce zero-filled page stat count
> clean TODO list
You can add Reviewed-by: Ric Mason <ric.masonn@gmail.com> to this patchset.
>
> drivers/staging/zcache/TODO | 3 +-
> drivers/staging/zcache/debug.c | 5 +-
> drivers/staging/zcache/debug.h | 77 +++++++++++++---------
> drivers/staging/zcache/zcache-main.c | 147 ++++++++++++++++++++++++++++++----
> 4 files changed, 185 insertions(+), 47 deletions(-)
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 14+ messages in thread