From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 77ED56B0038 for ; Thu, 27 Apr 2017 14:34:28 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id 194so32352697pfv.11 for ; Thu, 27 Apr 2017 11:34:28 -0700 (PDT) Received: from mail-wr0-x242.google.com (mail-wr0-x242.google.com. [2a00:1450:400c:c0c::242]) by mx.google.com with ESMTPS id l138si3385525wmd.2.2017.04.27.11.34.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Apr 2017 11:34:27 -0700 (PDT) Received: by mail-wr0-x242.google.com with SMTP id v42so4703203wrc.3 for ; Thu, 27 Apr 2017 11:34:27 -0700 (PDT) Subject: Re: [PATCH 0/3 v3] ARM/ARM64: silence large module first time allocation References: <20170427181902.28829-1-f.fainelli@gmail.com> <56EE35F5-97F9-4EA4-894B-581E7AE09A78@linaro.org> From: Florian Fainelli Message-ID: Date: Thu, 27 Apr 2017 11:34:21 -0700 MIME-Version: 1.0 In-Reply-To: <56EE35F5-97F9-4EA4-894B-581E7AE09A78@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org, Russell King , Catalin Marinas , Will Deacon , Andrew Morton , Michal Hocko , zijun_hu , "Kirill A. Shutemov" , Andrey Ryabinin , Chris Wilson , open list , "open list:MEMORY MANAGEMENT" , angus@angusclark.org On 04/27/2017 11:24 AM, Ard Biesheuvel wrote: > >> On 27 Apr 2017, at 19:18, Florian Fainelli wrote: >> >> With kernels built with CONFIG_ARM{,64}_MODULES_PLTS=y, the first allocation >> done from module space will fail, produce a general OOM allocation and also a >> vmap warning. The second allocation from vmalloc space may or may not be >> successful, but is actually the one we are interested about in these cases. >> >> This patch series passed __GFP_NOWARN to silence such allocations from the >> ARM/ARM64 module loader's first time allocation when the MODULES_PLT option is >> enabled, and also makes alloc_vmap_area() react to the caller setting >> __GFP_NOWARN to silence "vmap allocation for size..." messages. >> >> >> Changes in v3: >> - check for __GFP_NOWARN not set where the check for printk_ratelimited() >> is done, add Michal's Acked-by >> >> - use C conditionals and not CPP conditionals for IS_ENABLED(), add Ard's >> Reviewed-by tag >> > > Ok these look fine now. But are you sure that omitting the single pr_warn() gets rid of all of that? > Or do we need more patches on top? Since the caller now set __GFP_NOWARN, this propagates correctly to all functions called from alloc_vmap_area() like kmalloc_node(). With the patches applied, I only get the stuff that I would expect: # echo 8 7 4 1 > /proc/sys/kernel/printk # insmod huge.ko [ 59.285547] huge: loading out-of-tree module taints kernel. [ 59.328553] big_init: I am a big module using 3932160 bytes of data! # > > >> Changes in v2: >> >> - check __GFP_NOWARN out of the printk_ratelimited() check (Michal) >> >> Here is an example of what we would get without these two patches, pretty >> scary huh? >> >> # insmod /mnt/nfs/huge.ko >> [ 22.114143] random: nonblocking pool is initialized >> [ 22.183575] vmap allocation for size 15736832 failed: use vmalloc= to increase size. >> [ 22.191873] vmalloc: allocation failure: 15729534 bytes >> [ 22.197112] insmod: page allocation failure: order:0, mode:0xd0 >> [ 22.203048] CPU: 2 PID: 1506 Comm: insmod Tainted: G O 4.1.20-1.9pre-01082-gbbbff07bc3ce #9 >> [ 22.212536] Hardware name: Broadcom STB (Flattened Device Tree) >> [ 22.218480] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) >> [ 22.226238] [] (show_stack) from [] (dump_stack+0x90/0xa4) >> [ 22.233473] [] (dump_stack) from [] (warn_alloc_failed+0x104/0x144) >> [ 22.241490] [] (warn_alloc_failed) from [] (__vmalloc_node_range+0x170/0x218) >> [ 22.250375] [] (__vmalloc_node_range) from [] (module_alloc+0x50/0xac) >> [ 22.258651] [] (module_alloc) from [] (module_alloc_update_bounds+0xc/0x6c) >> [ 22.267360] [] (module_alloc_update_bounds) from [] (load_module+0x8ec/0x2058) >> [ 22.276329] [] (load_module) from [] (SyS_init_module+0xf0/0x174) >> [ 22.284170] [] (SyS_init_module) from [] (ret_fast_syscall+0x0/0x3c) >> [ 22.292277] Mem-Info: >> [ 22.294567] active_anon:5236 inactive_anon:1773 isolated_anon:0 >> [ 22.294567] active_file:1 inactive_file:3822 isolated_file:0 >> [ 22.294567] unevictable:0 dirty:0 writeback:0 unstable:0 >> [ 22.294567] slab_reclaimable:238 slab_unreclaimable:1594 >> [ 22.294567] mapped:855 shmem:2950 pagetables:36 bounce:0 >> [ 22.294567] free:39031 free_pcp:198 free_cma:3928 >> [ 22.327196] DMA free:156124kB min:1880kB low:2348kB high:2820kB active_anon:20944kB inactive_anon:7092kB active_file:4kB inactive_file:15288kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:262144kB managed:227676kB mlocked:0kB dirty:0kB writeback:0kB mapped:3420kB shmem:11800kB slab_reclaimable:952kB slab_unreclaimable:6376kB kernel_stack:560kB pagetables:144kB unstable:0kB bounce:0kB free_pcp:792kB local_pcp:68kB free_cma:15712kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no >> [ 22.371631] lowmem_reserve[]: 0 0 0 0 >> [ 22.375372] HighMem free:0kB min:128kB low:128kB high:128kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:2883584kB managed:0kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes >> [ 22.416249] lowmem_reserve[]: 0 0 0 0 >> [ 22.419986] DMA: 3*4kB (UEM) 4*8kB (UE) 1*16kB (M) 4*32kB (UEMC) 3*64kB (EMC) 1*128kB (E) 4*256kB (UEMC) 2*512kB (UE) 2*1024kB (MC) 4*2048kB (UEMC) 35*4096kB (MRC) = 156156kB >> [ 22.435922] HighMem: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 0kB >> [ 22.446130] 6789 total pagecache pages >> [ 22.449889] 0 pages in swap cache >> [ 22.453212] Swap cache stats: add 0, delete 0, find 0/0 >> [ 22.458447] Free swap = 0kB >> [ 22.461334] Total swap = 0kB >> [ 22.464222] 786432 pages RAM >> [ 22.467110] 720896 pages HighMem/MovableOnly >> [ 22.471388] 725417 pages reserved >> [ 22.474711] 4096 pages cma reserved >> [ 22.511310] big_init: I am a big module using 3932160 bytes of data! >> >> Florian Fainelli (3): >> mm: Silence vmap() allocation failures based on caller gfp_flags >> ARM: Silence first allocation with CONFIG_ARM_MODULE_PLTS=y >> arm64: Silence first allocation with CONFIG_ARM64_MODULE_PLTS=y >> >> arch/arm/kernel/module.c | 11 +++++++++-- >> arch/arm64/kernel/module.c | 7 ++++++- >> mm/vmalloc.c | 2 +- >> 3 files changed, 16 insertions(+), 4 deletions(-) >> >> -- >> 2.9.3 >> -- Florian -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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