Messages in this thread Patch in this message | | | From | Sergey Senozhatsky <> | Subject | [PATCH v4 2/2] zram: try vmalloc() after kmalloc() | Date | Tue, 1 Dec 2015 21:36:30 +0900 |
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From: Kyeongdon Kim <kyeongdon.kim@lge.com>
When we're using LZ4 multi compression streams for zram swap, we found out page allocation failure message in system running test. That was not only once, but a few(2 - 5 times per test). Also, some failure cases were continually occurring to try allocation order 3.
In order to make parallel compression private data, we should call kzalloc() with order 2/3 in runtime(lzo/lz4). But if there is no order 2/3 size memory to allocate in that time, page allocation fails. This patch makes to use vmalloc() as fallback of kmalloc(), this prevents page alloc failure warning.
After using this, we never found warning message in running test, also It could reduce process startup latency about 60-120ms in each case.
For reference a call trace :
Binder_1: page allocation failure: order:3, mode:0x10c0d0 CPU: 0 PID: 424 Comm: Binder_1 Tainted: GW 3.10.49-perf-g991d02b-dirty #20 Call trace: [<ffffffc0002069c8>] dump_backtrace+0x0/0x270 [<ffffffc000206c48>] show_stack+0x10/0x1c [<ffffffc000cb51c8>] dump_stack+0x1c/0x28 [<ffffffc0002bbfc8>] warn_alloc_failed+0xfc/0x11c [<ffffffc0002bf518>] __alloc_pages_nodemask+0x724/0x7f0 [<ffffffc0002bf5f8>] __get_free_pages+0x14/0x5c [<ffffffc0002ed6a4>] kmalloc_order_trace+0x38/0xd8 [<ffffffc0005d9738>] zcomp_lz4_create+0x2c/0x38 [<ffffffc0005d78f0>] zcomp_strm_alloc+0x34/0x78 [<ffffffc0005d7a58>] zcomp_strm_multi_find+0x124/0x1ec [<ffffffc0005d7c14>] zcomp_strm_find+0xc/0x18 [<ffffffc0005d8fa0>] zram_bvec_rw+0x2fc/0x780 [<ffffffc0005d9680>] zram_make_request+0x25c/0x2d4 [<ffffffc00040f8ac>] generic_make_request+0x80/0xbc [<ffffffc00040f98c>] submit_bio+0xa4/0x15c [<ffffffc0002e8bb0>] __swap_writepage+0x218/0x230 [<ffffffc0002e8c04>] swap_writepage+0x3c/0x4c [<ffffffc0002c7384>] shrink_page_list+0x51c/0x8d0 [<ffffffc0002c7e88>] shrink_inactive_list+0x3f8/0x60c [<ffffffc0002c86c8>] shrink_lruvec+0x33c/0x4cc [<ffffffc0002c8894>] shrink_zone+0x3c/0x100 [<ffffffc0002c8c10>] try_to_free_pages+0x2b8/0x54c [<ffffffc0002bf308>] __alloc_pages_nodemask+0x514/0x7f0 [<ffffffc0002bf5f8>] __get_free_pages+0x14/0x5c [<ffffffc0003446cc>] proc_info_read+0x50/0xe4 [<ffffffc0002f5204>] vfs_read+0xa0/0x12c [<ffffffc0002f59c8>] SyS_read+0x44/0x74 DMA: 3397*4kB (MC) 26*8kB (RC) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 13796kB
[minchan@kernel.org: change vmalloc gfp and adding comment about gfp] [sergey.senozhatsky@gmail.com: tweak comments and styles] Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> --- drivers/block/zram/zcomp_lz4.c | 23 +++++++++++++++++++++-- drivers/block/zram/zcomp_lzo.c | 23 +++++++++++++++++++++-- 2 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/drivers/block/zram/zcomp_lz4.c b/drivers/block/zram/zcomp_lz4.c index ee44b51..dd60831 100644 --- a/drivers/block/zram/zcomp_lz4.c +++ b/drivers/block/zram/zcomp_lz4.c @@ -10,17 +10,36 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/lz4.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> #include "zcomp_lz4.h" static void *zcomp_lz4_create(void) { - return kzalloc(LZ4_MEM_COMPRESS, GFP_NOIO); + void *ret; + + /* + * This function can be called in swapout/fs write path + * so we can't use GFP_FS|IO. And it assumes we already + * have at least one stream in zram initialization so we + * don't do best effort to allocate more stream in here. + * A default stream will work well without further multiple + * streams. That's why we use NORETRY | NOWARN. + */ + ret = kzalloc(LZ4_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY | + __GFP_NOWARN); + if (!ret) + ret = __vmalloc(LZ4_MEM_COMPRESS, + GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN | + __GFP_ZERO | __GFP_HIGHMEM, + PAGE_KERNEL); + return ret; } static void zcomp_lz4_destroy(void *private) { - kfree(private); + kvfree(private); } static int zcomp_lz4_compress(const unsigned char *src, unsigned char *dst, diff --git a/drivers/block/zram/zcomp_lzo.c b/drivers/block/zram/zcomp_lzo.c index 683ce04..edc5499 100644 --- a/drivers/block/zram/zcomp_lzo.c +++ b/drivers/block/zram/zcomp_lzo.c @@ -10,17 +10,36 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/lzo.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> #include "zcomp_lzo.h" static void *lzo_create(void) { - return kzalloc(LZO1X_MEM_COMPRESS, GFP_NOIO); + void *ret; + + /* + * This function can be called in swapout/fs write path + * so we can't use GFP_FS|IO. And it assumes we already + * have at least one stream in zram initialization so we + * don't do best effort to allocate more stream in here. + * A default stream will work well without further multiple + * streams. That's why we use NORETRY | NOWARN. + */ + ret = kzalloc(LZO1X_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY | + __GFP_NOWARN); + if (!ret) + ret = __vmalloc(LZO1X_MEM_COMPRESS, + GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN | + __GFP_ZERO | __GFP_HIGHMEM, + PAGE_KERNEL); + return ret; } static void lzo_destroy(void *private) { - kfree(private); + kvfree(private); } static int lzo_compress(const unsigned char *src, unsigned char *dst, -- 2.6.2
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