Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753831AbbK3KmH (ORCPT ); Mon, 30 Nov 2015 05:42:07 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:53484 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753598AbbK3KmF (ORCPT ); Mon, 30 Nov 2015 05:42:05 -0500 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: kyeongdon.kim@lge.com X-Original-SENDERIP: 10.168.83.150 X-Original-MAILFROM: kyeongdon.kim@lge.com Subject: Re: Re: [PATCH v3 2/2] zram: try vmalloc() after kmalloc() To: Minchan Kim , Sergey Senozhatsky References: <1448597449-17579-1-git-send-email-sergey.senozhatsky@gmail.com> <20151130071053.GB3262@bbox> Cc: Andrew Morton , linux-kernel@vger.kernel.org, Sergey Senozhatsky From: "kyeongdon.kim" Message-ID: <565C27FA.407@lge.com> Date: Mon, 30 Nov 2015 19:42:02 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151130071053.GB3262@bbox> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3821 Lines: 90 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 >> >> 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: >> [] dump_backtrace+0x0/0x270 >> [] show_stack+0x10/0x1c >> [] dump_stack+0x1c/0x28 >> [] warn_alloc_failed+0xfc/0x11c >> [] __alloc_pages_nodemask+0x724/0x7f0 >> [] __get_free_pages+0x14/0x5c >> [] kmalloc_order_trace+0x38/0xd8 >> [] zcomp_lz4_create+0x2c/0x38 >> [] zcomp_strm_alloc+0x34/0x78 >> [] zcomp_strm_multi_find+0x124/0x1ec >> [] zcomp_strm_find+0xc/0x18 >> [] zram_bvec_rw+0x2fc/0x780 >> [] zram_make_request+0x25c/0x2d4 >> [] generic_make_request+0x80/0xbc >> [] submit_bio+0xa4/0x15c >> [] __swap_writepage+0x218/0x230 >> [] swap_writepage+0x3c/0x4c >> [] shrink_page_list+0x51c/0x8d0 >> [] shrink_inactive_list+0x3f8/0x60c >> [] shrink_lruvec+0x33c/0x4cc >> [] shrink_zone+0x3c/0x100 >> [] try_to_free_pages+0x2b8/0x54c >> [] __alloc_pages_nodemask+0x514/0x7f0 >> [] __get_free_pages+0x14/0x5c >> [] proc_info_read+0x50/0xe4 >> [] vfs_read+0xa0/0x12c >> [] 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 >> Signed-off-by: Minchan Kim > > 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) { 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/