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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 02072CAC5B9 for ; Tue, 30 Sep 2025 00:49:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5E0678E000B; Mon, 29 Sep 2025 20:49:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B8168E0002; Mon, 29 Sep 2025 20:49:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4F4938E000B; Mon, 29 Sep 2025 20:49:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 3FA7D8E0002 for ; Mon, 29 Sep 2025 20:49:13 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id BDA6113B3B7 for ; Tue, 30 Sep 2025 00:49:12 +0000 (UTC) X-FDA: 83944082544.14.285E221 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf03.hostedemail.com (Postfix) with ESMTP id 0CF8720010 for ; Tue, 30 Sep 2025 00:49:10 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=QhK76q+a; spf=pass (imf03.hostedemail.com: domain of sj@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1759193351; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=9P8i0lPxwdWcH06Qu/q8Q7cHVskIwe2qq5Z3Y/6PcLs=; b=2p6c3mwwIHMj+a/jB6GBU734BLcAm164HCTqRYFcriTJtAEaYFk2LV88IJAKZX7/A+6Dmy E4O3MpwxGQyP3hvuJ31Qblz7c8w3Z6IdtlT2UP4IKy3bLE6nBmPZTf4Y1AyPqUgsFhX3AF qIwmruXsS9jRwsODDss1mfEwMzWaQMY= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=QhK76q+a; spf=pass (imf03.hostedemail.com: domain of sj@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1759193351; a=rsa-sha256; cv=none; b=VgEHCr87h1PRWFsF3WDpe023/81MKsjbXPEwHVXyF1Ut/070b3hhrJHaz/vW+JAyC13JHg 2XXfGaLc5L0ZC/4yldfypn+wfAGg1V3IoLu35A1RRz4z3lE/opVy4tLjQnYByOlONP5lXa qKrshc8YjJg6WVdeuwUA/A5YQRwtgkc= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id A7A60433CB; Tue, 30 Sep 2025 00:49:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6388CC4CEF4; Tue, 30 Sep 2025 00:49:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759193349; bh=Dmx25bmLQf6ATWT8g8tetZDOFF0vBbRp6vW8hTDcyvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QhK76q+aJngACoGRYQpbuwf9uBLxE7n+FfDFAI6Bz7CRfp9ohr/mdN6MzNy4Y+cbF PJP3xHR20cu+BzyuUy7Gl3Qq82r3fg7EjaQpikJUEUz5+5xCPugK97xs6t9FDM0xyY Hd+vzUifNrzATwg4X9wlRNkTkZm/oMoYzEk7KqYkK9Y6hICU0FW4U7iL6UfuxGRsHK wdZSrpIjBc+gy+9jQDWi0BHwdvjG4pGW4CoT5SkisCEv+htE+KSj5g3N+hDZapdrKc /pSALxpvqkak+zEX88oxB+WXrJ9oaDh9IV3eztg7ZJzgtaHheTeX3az3YS6ksRPxUh ZV/EXsYxjXcrw== From: SeongJae Park To: Xinyu Zheng Cc: SeongJae Park , Andrew Morton , "Paul E . McKenney" , Peter Zijlstra , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, zouyipeng@huawei.com, Hugh Dickins Subject: Re: [BUG REPORT] mm/damon: softlockup when kdamond walk page with cpu hotplug Date: Mon, 29 Sep 2025 17:49:07 -0700 Message-Id: <20250930004907.55388-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 0CF8720010 X-Stat-Signature: tnnah655u7iirbpntuhhybce5tujnq1m X-HE-Tag: 1759193350-398143 X-HE-Meta: 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 rXZ7gtqc Wv5uzzt5YlkZFY6J95VDANNUR+rkJHv3O6kaefHLhtwrR3/oYLhwcbqBfNfhWdFrRK/g50aBwdZe2d028D/5SPS5pv4zj0lZa8FS2mn7azqw4SfnRWc1ZvAdqTahWateiLoUyFegT+dQ/+Hezlg2sEUp0BhpafwPHdxauM4LcwHcv4pLGpi7IUD8PGH8/F8UMBLbvdOX7xjV90uPXcGCoh5aIwB4UE9RWsCLMEBmUp8AwuO6FOQKkVSty19L1r6XHxLGEUi0brtYGxYpvPOuZ3cOmqQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 25 Sep 2025 19:11:13 +0800 Xinyu Zheng wrote: > > > On 9/20/2025 6:42 PM, SeongJae Park wrote: > > On Fri, 19 Sep 2025 20:56:56 -0700 (PDT) Hugh Dickins wrote: > > > >> On Thu, 18 Sep 2025, SeongJae Park wrote: > >> > >>> Hello, > >>> > >>> On Thu, 18 Sep 2025 03:00:29 +0000 Xinyu Zheng wrote: > >>> > >>>> A softlockup issue was found with stress test: [...] > > Xinyu, could you please test if the below attached patch fixes your issue and > > let us know the result? > > > > If Xinyu confirms the validity of the fix and no one objects to the above plan, > > I will post the fix as a formal one with a better commit message. > > > > Hi, SJ. The below attached patch is works! > > These days, I reproduced the same softlockup scenario for three times. > It can be reproduced around an hour when I increase the memory pressure. > Then I patched the below fix, and ran the same testcase whole day, > softlock didn't trigger again. > > Sorry for the long wait. Thanks again for your solution and explanation! Sorry for late response, and thank you for confirming that the fix works. I just posted it as a formal patch: https://lore.kernel.org/20250930004410.55228-1-sj@kernel.org Thanks, SJ [...]