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 CC50CC4332F for ; Fri, 25 Mar 2022 01:34:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357391AbiCYBgE (ORCPT ); Thu, 24 Mar 2022 21:36:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357357AbiCYBfY (ORCPT ); Thu, 24 Mar 2022 21:35:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A60F01013 for ; Thu, 24 Mar 2022 18:33:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0C50F60B08 for ; Fri, 25 Mar 2022 01:33:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 671E1C340EC; Fri, 25 Mar 2022 01:33:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648171985; bh=wm9Dsfu0HhA1AQRiHi75sYSXCTem54iIxiroJL/8LZ0=; h=Date:To:From:Subject:From; b=q162x2kWm8fdJ1qI96wnOrXJIdbzb3KMUvYIGJnaqALbFpBOnm8KUtYzSG2ef7yXX HDQiTed/fGgRiux12O3mvC/RY9kHiRoDiMr/UHUJFCNAKwVBlfvbS7Ul5zm4WNXaaI pgW8AqqLu0tBrdjuTIGZy/0+dKpUpkIiA40iRn8k= Date: Thu, 24 Mar 2022 18:33:04 -0700 To: mm-commits@vger.kernel.org, wangkefeng.wang@huawei.com, glider@google.com, elver@google.com, dvyukov@google.com, dlatypov@google.com, davidgow@google.com, brendanhiggins@google.com, liupeng256@huawei.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged] kfence-test-try-to-avoid-test_gfpzero-trigger-rcu_stall.patch removed from -mm tree Message-Id: <20220325013305.671E1C340EC@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: kfence: test: try to avoid test_gfpzero trigger rcu_stall has been removed from the -mm tree. Its filename was kfence-test-try-to-avoid-test_gfpzero-trigger-rcu_stall.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Peng Liu Subject: kfence: test: try to avoid test_gfpzero trigger rcu_stall When CONFIG_KFENCE_NUM_OBJECTS is set to a big number, kfence kunit-test-case test_gfpzero will eat up nearly all the CPU's resources and rcu_stall is reported as the following log which is cut from a physical server. rcu: INFO: rcu_sched self-detected stall on CPU rcu: 68-....: (14422 ticks this GP) idle=6ce/1/0x4000000000000002 softirq=592/592 fqs=7500 (t=15004 jiffies g=10677 q=20019) Task dump for CPU 68: task:kunit_try_catch state:R running task stack: 0 pid: 9728 ppid: 2 flags:0x0000020a Call trace: dump_backtrace+0x0/0x1e4 show_stack+0x20/0x2c sched_show_task+0x148/0x170 ... rcu_sched_clock_irq+0x70/0x180 update_process_times+0x68/0xb0 tick_sched_handle+0x38/0x74 ... gic_handle_irq+0x78/0x2c0 el1_irq+0xb8/0x140 kfree+0xd8/0x53c test_alloc+0x264/0x310 [kfence_test] test_gfpzero+0xf4/0x840 [kfence_test] kunit_try_run_case+0x48/0x20c kunit_generic_run_threadfn_adapter+0x28/0x34 kthread+0x108/0x13c ret_from_fork+0x10/0x18 To avoid rcu_stall and unacceptable latency, a schedule point is added to test_gfpzero. Link: https://lkml.kernel.org/r/20220309083753.1561921-4-liupeng256@huawei.com Signed-off-by: Peng Liu Reviewed-by: Marco Elver Tested-by: Brendan Higgins Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Wang Kefeng Cc: Daniel Latypov Cc: David Gow Signed-off-by: Andrew Morton --- mm/kfence/kfence_test.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/kfence/kfence_test.c~kfence-test-try-to-avoid-test_gfpzero-trigger-rcu_stall +++ a/mm/kfence/kfence_test.c @@ -627,6 +627,7 @@ static void test_gfpzero(struct kunit *t kunit_warn(test, "giving up ... cannot get same object back\n"); return; } + cond_resched(); } for (i = 0; i < size; i++) _ Patches currently in -mm which might be from liupeng256@huawei.com are