From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15CC9C7EE25 for ; Mon, 12 Jun 2023 08:36:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233017AbjFLIgP (ORCPT ); Mon, 12 Jun 2023 04:36:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232490AbjFLIgI (ORCPT ); Mon, 12 Jun 2023 04:36:08 -0400 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C57910B; Mon, 12 Jun 2023 01:36:00 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R541e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0VkvdYic_1686558955; Received: from 30.240.118.86(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VkvdYic_1686558955) by smtp.aliyun-inc.com; Mon, 12 Jun 2023 16:35:57 +0800 Message-ID: <81e17acb-68ef-c3e5-fb90-de7b3b13dde4@linux.alibaba.com> Date: Mon, 12 Jun 2023 16:35:52 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.11.1 Subject: Re: [PATCH 2/2] perf/ring_buffer: Fix high-order allocations for AUX space with correct MAX_ORDER limit Content-Language: en-US To: Leo Yan Cc: alexander.shishkin@linux.intel.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, mark.rutland@arm.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Baolin Wang References: <20230612052452.53425-1-xueshuai@linux.alibaba.com> <20230612052452.53425-3-xueshuai@linux.alibaba.com> <20230612083025.GC217089@leoy-huanghe.lan> From: Shuai Xue In-Reply-To: <20230612083025.GC217089@leoy-huanghe.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/6/12 16:30, Leo Yan wrote: > On Mon, Jun 12, 2023 at 01:24:52PM +0800, Shuai Xue wrote: >> When perf-record with a large AUX area, e.g 2GB: >> >> #perf record -C 0 -m ,2G -e arm_spe_0// -- sleep 1 >> >> it reveals a WARNING with __alloc_pages: >> >> [ 48.888553] ------------[ cut here ]------------ >> [ 48.888559] WARNING: CPU: 39 PID: 17438 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248 >> [ 48.888569] Modules linked in: ip6table_filter(E) ip6_tables(E) iptable_filter(E) ebtable_nat(E) ebtables(E) vfat(E) fat(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) ghash_ce(E) sm4_ce_cipher(E) sm4(E) sha2_ce(E) sha256_arm64(E) sha1_ce(E) acpi_ipmi(E) sbsa_gwdt(E) sg(E) ipmi_si(E) ipmi_devintf(E) ipmi_msghandler(E) ip_tables(E) sd_mod(E) ast(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) nvme(E) sysimgblt(E) i2c_algo_bit(E) nvme_core(E) drm_shmem_helper(E) ahci(E) t10_pi(E) libahci(E) drm(E) crc64_rocksoft(E) i40e(E) crc64(E) libata(E) i2c_core(E) >> [ 48.888610] CPU: 39 PID: 17438 Comm: perf Kdump: loaded Tainted: G E 6.3.0-rc4+ #56 >> [ 48.888613] Hardware name: Default Default/Default, BIOS 1.2.M1.AL.P.139.00 03/22/2023 >> [ 48.888614] pstate: 23400009 (nzCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) >> [ 48.888616] pc : __alloc_pages+0x1ec/0x248 >> [ 48.888619] lr : rb_alloc_aux_page+0x78/0xe0 >> [ 48.888622] sp : ffff800037c5b9e0 >> [ 48.888623] pmr_save: 000000e0 >> [ 48.888624] x29: ffff800037c5b9e0 x28: ffff00082743b800 x27: 0000000000000000 >> [ 48.888627] x26: 0000000000080000 x25: ffff000000000000 x24: ffff000860b21380 >> [ 48.888629] x23: ffff8000093fd3c0 x22: ffff00081a4a2080 x21: 000000000000000b >> [ 48.888631] x20: 0000000000000000 x19: 000000000000000b x18: 0000000000000020 >> [ 48.888634] x17: 0000000000000000 x16: ffff800008f05be8 x15: ffff00081a4a2610 >> [ 48.888636] x14: 0000000000000000 x13: 323173656761705f x12: ffff00477fffeb90 >> [ 48.888638] x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000083608a0 >> [ 48.888641] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000040 >> [ 48.888643] x5 : 000000000007f400 x4 : 0000000000000000 x3 : 0000000000000000 >> [ 48.888645] x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000012dc0 >> [ 48.888648] Call trace: >> [ 48.888650] __alloc_pages+0x1ec/0x248 >> [ 48.888653] rb_alloc_aux_page+0x78/0xe0 >> [ 48.888654] rb_alloc_aux+0x13c/0x298 >> [ 48.888656] perf_mmap+0x468/0x688 >> [ 48.888659] mmap_region+0x308/0x8a8 >> [ 48.888662] do_mmap+0x3c0/0x528 >> [ 48.888664] vm_mmap_pgoff+0xf4/0x1b8 >> [ 48.888666] ksys_mmap_pgoff+0x18c/0x218 >> [ 48.888668] __arm64_sys_mmap+0x38/0x58 >> [ 48.888671] invoke_syscall+0x50/0x128 >> [ 48.888673] el0_svc_common.constprop.0+0x58/0x188 >> [ 48.888674] do_el0_svc+0x34/0x50 >> [ 48.888676] el0_svc+0x34/0x108 >> [ 48.888679] el0t_64_sync_handler+0xb8/0xc0 >> [ 48.888681] el0t_64_sync+0x1a4/0x1a8 >> [ 48.888686] ---[ end trace 0000000000000000 ]--- >> >> The problem is that the high-order pages for AUX area is allocated with >> an order of MAX_ORDER. Obviously, this is a bogus. >> >> Fix it with an order of MAX_ORDER - 1 at maximum. >> >> Fixes: 0a4e38e64f5e ("perf: Support high-order allocations for AUX space") >> Signed-off-by: Shuai Xue > > LGTM: > > Reviewed-by: Leo Yan Thank you :) Cheers Shuai > >> --- >> kernel/events/ring_buffer.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c >> index 273a0fe..d6bbdb7 100644 >> --- a/kernel/events/ring_buffer.c >> +++ b/kernel/events/ring_buffer.c >> @@ -609,8 +609,8 @@ static struct page *rb_alloc_aux_page(int node, int order) >> { >> struct page *page; >> >> - if (order > MAX_ORDER) >> - order = MAX_ORDER; >> + if (order >= MAX_ORDER) >> + order = MAX_ORDER - 1; >> >> do { >> page = alloc_pages_node(node, PERF_AUX_GFP, order); >> -- >> 1.8.3.1 >>