From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F1297606A8AE for ; Thu, 12 Nov 2026 08:42:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=O/G0E/GO Received: by kanga.kvack.org (Postfix) id 16DE56B05CE; Thu, 12 Nov 2026 03:42:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 11EB76B05CF; Thu, 12 Nov 2026 03:42:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 035266B05D1; Thu, 12 Nov 2026 03:42:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id D18886B05CE for ; Thu, 12 Nov 2026 03:42:19 -0500 (EST) Received: from smtpin18.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6857F160478 for ; Thu, 12 Nov 2026 08:42:19 +0000 (UTC) X-FDA: 85425825198.18.386C478 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf10.hostedemail.com (Postfix) with ESMTP id CDDABC0006 for ; Thu, 12 Nov 2026 08:42:17 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="O/G0E/GO"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sashiko-bot@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1794472937; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ial8iAsSa5eOrYsCj4SMZLA9EuKpEQEbZW4C+PxDTJA=; b=ycbssD4yBbAJr3XPptxMifhTpYZQk1oKDKML9dEEpwSfuwBfnvow3iU5MivrmRyue/t3b6 Une+XTQ4gIZQU1CUC03Q0uszwtPuAI+tWgyRQgPBdeUSPPEHTtW7pcw2oBvu0is2vg+2uS 8aRY4sYAdfLsY2u/Iqf9vmpf8s63/nw= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="O/G0E/GO"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of sashiko-bot@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=sashiko-bot@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1794472937; b=1epOQ4lUor3fTCnPvHcijKr5RngeEDAqfRQHa+4LqqYZx72h5rktARPdvZGclyI+akPNRs pW2EarmM8mJHnyEjGYrp9qNrVzT5p7tuFUb7nCTNArUBKWtLlR1FqkUGQ21fGv+p5zULqQ 7e8IS177TW7OvJzIe5yTDR8EcZuItTc= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 2A8F641450; Thu, 12 Nov 2026 08:42:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E7D31F00A05; Thu, 12 Nov 2026 08:42:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794472937; bh=ial8iAsSa5eOrYsCj4SMZLA9EuKpEQEbZW4C+PxDTJA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=O/G0E/GOhzhWvj3+aPjuf/R81zEodFSmOd/3hcJXfsGxzBO9PPKa9mlTwPJcax3iB OdVCU1tSe9ntSNCMaNVqhAKbp00jbrwhPiLDlraF8pCZsdU08OTlvBi2e/a1g26EZb 959/ReDHNObr+I8FCl+MWYtz9BJ+FZIllaNxscVo9Z/V3p8sLQx+aaN9ITpw347yhS qPSC7uFh8akjso25gvhq3e10LYYf3z4Vlcq2hPhORVs68vxkSyaGUhwfD+kbHW2fSO rFnl+8q2KMWAH5ZzLblj2XKbL3h7faSTarrZrWPG1dLixZjTGLEgdnnvgpAVgTMt0u Xn0VDYHJDiHBw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] mm/compaction: Mark concurrent compact_considered accesses Reply-To: sashiko-reviews@lists.linux.dev To: "Zhu Jun" , akpm@linux-foundation.org Cc: vbabka@kernel.org, hannes@cmpxchg.org, ziy@nvidia.com, rostedt@goodmis.org, mhiramat@kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, syzbot+212c2d1f47994035cf7f@syzkaller.appspotmail.com In-Reply-To: <20261111084205.80997-1-zhujun2@cmss.chinamobile.com> References: <20261111084205.80997-1-zhujun2@cmss.chinamobile.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 12 Nov 2026 08:42:16 +0000 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: CDDABC0006 X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Stat-Signature: bih6333qoaoq87h14ogjbcq9e3caq7b7 X-HE-Tag: 1794472937-790951 X-HE-Meta: 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 oJXwlxbx 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: Thank you for your contribution! Sashiko AI review found no new issues in this patch, but noticed 1 related pre-existing issue it does not introduce: - [Medium] mm: data race in compaction_deferred() [1] -- commit 065fba640e4d4df80527a642f4adcbe5f31c8683 Author: Zhu Jun mm/compaction: Mark concurrent compact_considered accesses This commit marks concurrent reads and writes to zone->compact_considered with READ_ONCE() and WRITE_ONCE() to avoid KCSAN data race reports. > diff --git a/mm/compaction.c b/mm/compaction.c > index a049415512c67..2ac6af7c1ee59 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -126,7 +126,7 @@ static unsigned long release_free_list(struct list_he= ad *freepages) > */ > static void defer_compaction(struct zone *zone, int order) > { > - zone->compact_considered =3D 0; > + WRITE_ONCE(zone->compact_considered, 0); > zone->compact_defer_shift++; > =20 > if (order < zone->compact_order_failed) > @@ -142,15 +142,16 @@ static void defer_compaction(struct zone *zone, int= order) > static bool compaction_deferred(struct zone *zone, int order) > { > unsigned long defer_limit =3D 1UL << zone->compact_defer_shift; [Severity: Medium] This problem wasn't introduced by this patch, but should concurrent accesses to zone->compact_defer_shift also be marked to avoid a data race [1]? Multiple CPUs performing page allocations under memory pressure call defer_compaction(), compaction_deferred(), compaction_defer_reset(), and compaction_restarting() concurrently without a common lock, reading and updating zone->compact_defer_shift via plain C accesses. This causes KCSAN warnings and can corrupt compaction deferral limits. [1] https://sashiko.dev/#/bug/linux-b61fd78e-8874-42f5-bbe1-bcd3914879cc --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261111084205.8099= 7-1-zhujun2@cmss.chinamobile.com?part=3D1