Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Matthew Wilcox <> | Subject | [PATCH v3 5/7] zram: Convert to using memset_l | Date | Fri, 24 Mar 2017 09:13:16 -0700 |
| |
From: Matthew Wilcox <mawilcox@microsoft.com>
zram was the motivation for creating memset_l(). Minchan Kim sees a 7% performance improvement on x86 with 100MB of non-zero deduplicatable data:
perf stat -r 10 dd if=/dev/zram0 of=/dev/null
vanilla: 0.232050465 seconds time elapsed ( +- 0.51% ) memset_l: 0.217219387 seconds time elapsed ( +- 0.07% )
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Tested-by: Minchan Kim <minchan@kernel.org> --- drivers/block/zram/zram_drv.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index e27d89a36c34..25dcad309695 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -157,20 +157,11 @@ static inline void update_used_max(struct zram *zram, } while (old_max != cur_max); } -static inline void zram_fill_page(char *ptr, unsigned long len, +static inline void zram_fill_page(void *ptr, unsigned long len, unsigned long value) { - int i; - unsigned long *page = (unsigned long *)ptr; - WARN_ON_ONCE(!IS_ALIGNED(len, sizeof(unsigned long))); - - if (likely(value == 0)) { - memset(ptr, 0, len); - } else { - for (i = 0; i < len / sizeof(*page); i++) - page[i] = value; - } + memset_l(ptr, value, len / sizeof(unsigned long)); } static bool page_same_filled(void *ptr, unsigned long *element) @@ -193,7 +184,7 @@ static bool page_same_filled(void *ptr, unsigned long *element) static void handle_same_page(struct bio_vec *bvec, unsigned long element) { struct page *page = bvec->bv_page; - void *user_mem; + char *user_mem; user_mem = kmap_atomic(page); zram_fill_page(user_mem + bvec->bv_offset, bvec->bv_len, element); -- 2.11.0
| ![\](/images/icornerr.gif) |