From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 43F44341650 for ; Thu, 16 Jul 2026 03:12:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784171543; cv=none; b=uSfItTGok6MBon3XYNGUt3WfU4DTJaeCWafdr4Gh99wsoluz3AFA7Pq9/qXyfwyPirqQC3TLhz3Ywhqax2ZxKj0/VsCaXhLOeXMM9Dz6aJpM7Y1hmbFtJBVe2gAYp8pXl61fkJH1bR/Toc1hKu1OG0m4drvmXwH+hnqCLbp3Q08= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784171543; c=relaxed/simple; bh=osdlP8fRTmDlri6Xp8ao4snWGd/hojSgNbhOchXZ0GI=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=oBZXn1niDsaIks6uti8/bjdU2RJr0NKG8wOKn4NY0iIBBYeyq6RuoKH3XO0prQWQz0HEVZyc6dbukd30pMwqeGQeHSHUGd0/cW09Zzt3gI5+7eBEvTa+w1IO5+DtpCBURdrJdQ/hXEwiCiOEtGgbHtriAz5xobrwjMrhphysxCQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PLJ48lCH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PLJ48lCH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 569981F000E9; Thu, 16 Jul 2026 03:12:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784171541; bh=osdlP8fRTmDlri6Xp8ao4snWGd/hojSgNbhOchXZ0GI=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=PLJ48lCHUks6sn1lwp4QMchtKWccfUE4O/a4CkqT9dMPEgYs47/rxVnL+NHJKeZyK 5O//Mw7t6rwM8Nu7MO4dsH9ROipg00drH0OlYcC5Y+fdVI4sy01u1skZVmC89vADRR rYo1UQJDfhupePqvVk40+Bc2FC/xD3HZRciw47tj1qYfOi63b+zYguBkeiPRd0z8z1 SEJOUFKOFinrvBbpm51LIN/1QbUMLzYBEiilTfEApFq/dV9bny5Nr1X3uATa6er9be R0aN/VhgFXT7uqBWJMzB9OOgF9itOC6ISfFAU5q7YgNIpDiH4tWNf7WP34OLi2RJTP NPk8H+BI2uqiA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v8 9/9] selftests: ftrace: Add wprobe trigger testcase Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TWFzYW1pIEhpcmFtYXRzdSAoR29vZ2xlKQ==?= Cc: linux-perf-users@vger.kernel.org In-Reply-To: <178417043960.209165.373192587945789724.stgit@devnote2> References: <178417033089.209165.16717079876036408877.stgit@devnote2> <178417043960.209165.373192587945789724.stgit@devnote2> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 16 Jul 2026 03:12:20 +0000 Message-Id: <20260716031221.569981F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] The selftest incorrectly assumes that unlinking a file (`rm`) wi= ll synchronously trigger `dentry_kill()`. This only works on filesystems th= at do not cache negative dentries (like `tmpfs`). On standard disk filesyst= ems (like `ext4`), the test will fail. -- --- Patch [9]: [PATCH v8 9/9] selftests: ftrace: Add wprobe trigger testcas= e --- commit 02c2b6c1500ba6cce360f9d5447d679e62801d61 Author: Masami Hiramatsu (Google) selftests: ftrace: Add wprobe trigger testcase This commit adds a testcase for checking wprobe triggers. It sets set_wprobe and clear_wprobe triggers on fprobe events to watch dentry access. > diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe= .tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe.tc > new file mode 100644 > index 0000000000000..5ffe43f886d1a > --- /dev/null > +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-wprobe.tc [ ... ] > +:;: "Start test workload" ;: > +echo 1 >> tracing_on > + > +echo aaa > $TMPDIR/hoge > +echo bbb > $TMPDIR/hoge > +echo ccc > $TMPDIR/hoge > +rm $TMPDIR/hoge > + > +:;: "Check trace results" ;: > +cat trace | grep watch > + > +:;: "Ensure wprobe becomes disabled again" ;: > +cat events/wprobes/watch/enable | grep 0 [Severity: Medium] Will this regression cause the test to fail when $TMPDIR is on a standard d= isk filesystem? This selftest appears to rely on rm synchronously triggering dentry_kill() = to fire the clear_wprobe trigger. While this works on memory-backed filesystems like tmpfs that do not cache negative dentries (their d_delete operation immediately leads to dentry_kil= l()), standard disk filesystems like ext4, xfs, or btrfs cache negative dentries = to optimize subsequent lookups.=20 On those filesystems, unlinking the file leaves the dentry hashed on the dc= ache LRU list, deferring dentry_kill() until memory pressure or a manual eviction occurs. This would cause the test to fail when checking if the wprobe is disabled. Does this need to trigger a manual cache eviction or ensure the test runs o= n a tmpfs mount to avoid failing? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/178417033089.209165= .16717079876036408877.stgit@devnote2?part=3D9