Messages in this thread | | | Subject | Re: Re: [PATCH v3 2/2] zram: try vmalloc() after kmalloc() | From | "kyeongdon.kim" <> | Date | Mon, 30 Nov 2015 19:42:02 +0900 |
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On 2015-11-30 오후 4:10, Minchan Kim wrote: > On Fri, Nov 27, 2015 at 01:10:49PM +0900, Sergey Senozhatsky wrote: >> 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: change vmalloc gfp and adding comment about gfp] >> [sergey: tweak comments and styles] >> Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com> >> Signed-off-by: Minchan Kim <minchan@kernel.org> > > Kyeongdon, Could you test this patch on your device? > > Thanks.
Sorry to have kept you waiting, Obviously, I couldn't see allocation fail message with this patch. But, there is something to make some delay(not sure yet this is normal).
static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp) { <snip>
zstrm->private = comp->backend->create(); ^ // sometimes, return 'null' continually(2-5times)
As you know, if there is 'null' return, this function is called again to get a memory in while() loop. I just checked this one with printk().
If you guys don't mind, I'll test more with trace log to check time delay.
However, If this is fully expectable status to you. I think I don't need to do it.
Thanks, Kyeongdon Kim
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