On Wed, Mar 13, 2013 at 09:42:16AM -0700, Dan Magenheimer wrote: >> From: Wanpeng Li [mailto:liwanp@xxxxxxxxxxxxxxxxxx] >> Sent: Wednesday, March 13, 2013 1:05 AM >> To: Andrew Morton >> Cc: Greg Kroah-Hartman; Dan Magenheimer; Seth Jennings; Konrad Rzeszutek Wilk; Minchan Kim; linux- >> mm@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Wanpeng Li >> Subject: [PATCH 4/4] zcache: add pageframes count once compress zero-filled pages twice > >Hi Wanpeng -- > >Thanks for taking on this task from the drivers/staging/zcache TODO list! > >> Since zbudpage consist of two zpages, two zero-filled pages compression >> contribute to one [eph|pers]pageframe count accumulated. > Hi Dan, >I'm not sure why this is necessary. The [eph|pers]pageframe count >is supposed to be counting actual pageframes used by zcache. Since >your patch eliminates the need to store zero pages, no pageframes >are needed at all to store zero pages, so it's not necessary >to increment zcache_[eph|pers]_pageframes when storing zero >pages. > Great point! It seems that we also don't need to caculate zcache_[eph|pers]_zpages for zero-filled pages. I will fix it in next version. :-) >Or am I misunderstanding your intent? > Regards, Wanpeng Li >Thanks, >Dan > >> Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx> >> --- >> drivers/staging/zcache/zcache-main.c | 25 +++++++++++++++++++++++-- >> 1 files changed, 23 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c >> index dd52975..7860ff0 100644 >> --- a/drivers/staging/zcache/zcache-main.c >> +++ b/drivers/staging/zcache/zcache-main.c >> @@ -544,6 +544,8 @@ static struct page *zcache_evict_eph_pageframe(void); >> static void *zcache_pampd_eph_create(char *data, size_t size, bool raw, >> struct tmem_handle *th) >> { >> + static ssize_t second_eph_zero_page; >> + static atomic_t second_eph_zero_page_atomic = ATOMIC_INIT(0); >> void *pampd = NULL, *cdata = data; >> unsigned clen = size; >> bool zero_filled = false; >> @@ -561,7 +563,14 @@ static void *zcache_pampd_eph_create(char *data, size_t size, bool raw, >> clen = 0; >> zero_filled = true; >> zcache_pages_zero++; >> - goto got_pampd; >> + second_eph_zero_page = atomic_inc_return( >> + &second_eph_zero_page_atomic); >> + if (second_eph_zero_page % 2 == 1) >> + goto got_pampd; >> + else { >> + atomic_sub(2, &second_eph_zero_page_atomic); >> + goto count_zero_page; >> + } >> } >> kunmap_atomic(user_mem); >> >> @@ -597,6 +606,7 @@ static void *zcache_pampd_eph_create(char *data, size_t size, bool raw, >> create_in_new_page: >> pampd = (void *)zbud_create_prep(th, true, cdata, clen, newpage); >> BUG_ON(pampd == NULL); >> +count_zero_page: >> zcache_eph_pageframes = >> atomic_inc_return(&zcache_eph_pageframes_atomic); >> if (zcache_eph_pageframes > zcache_eph_pageframes_max) >> @@ -621,6 +631,8 @@ out: >> static void *zcache_pampd_pers_create(char *data, size_t size, bool raw, >> struct tmem_handle *th) >> { >> + static ssize_t second_pers_zero_page; >> + static atomic_t second_pers_zero_page_atomic = ATOMIC_INIT(0); >> void *pampd = NULL, *cdata = data; >> unsigned clen = size, zero_filled = 0; >> struct page *page = (struct page *)(data), *newpage; >> @@ -644,7 +656,15 @@ static void *zcache_pampd_pers_create(char *data, size_t size, bool raw, >> clen = 0; >> zero_filled = 1; >> zcache_pages_zero++; >> - goto got_pampd; >> + second_pers_zero_page = atomic_inc_return( >> + &second_pers_zero_page_atomic); >> + if (second_pers_zero_page % 2 == 1) >> + goto got_pampd; >> + else { >> + atomic_sub(2, &second_pers_zero_page_atomic); >> + goto count_zero_page; >> + } >> + >> } >> kunmap_atomic(user_mem); >> >> @@ -698,6 +718,7 @@ create_pampd: >> create_in_new_page: >> pampd = (void *)zbud_create_prep(th, false, cdata, clen, newpage); >> BUG_ON(pampd == NULL); >> +count_zero_page: >> zcache_pers_pageframes = >> atomic_inc_return(&zcache_pers_pageframes_atomic); >> if (zcache_pers_pageframes > zcache_pers_pageframes_max) >> -- >> 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>