From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793908690; b=ItB3KUwITY0j9GIm/RJiiG1EAfCW4ayyErDlLNBuXd1Pa2hQeq+zpAEmmjRQEXQdGQBC dhZJDQ1mBO6BuRlb+UHMKnLbLrypvVaG7yveBbBc/ZVZOnwjX2bmfrGpSOFC0PVxRqfub 5oZOOxyjXk0Z5vsyvCxRRB1Rlm1BdhfOsKeGtTrOPJD346KNfflJ+M+SPq8zQ9fwT0kEm CqUNitCyRLrVov1vrzAdgJrxGYFRLo78wj0OXRtnca4oPoG/aEKUDSLYvMmBoQrV9o1o2 ka4ulNrISUMi/Zn+guvaYgoNY2OO9i2uYvVApINzBgCUVulbJZlqk2oLgM32VcNj7bg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793908690; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=qyGxYG8j9RHg2vyof7KTGe46hg815xlN1LVcZ72aA7U=; b=GU+/C2kdK/7hAkEfJ94Bb9mAVC8Jez8BF0ffTlwOiakL0PDvCyiH1nApsV8OR2EFkUyz bjFa/NJOZHzsGBdRzRIpJ9+dbOlw6E7M3gR4h/hAKQtgZdQxIVC3YFbrU8FSugfYZAGxT Ocgofe1lndPzOQRJ9+249X1KBxUp6EDyRODbLNycWra6juDLWkFWiGDyBxOsBFtJELK5s AolKXefItYwBTo/JoUnQ8dPuJqi/sytzdcmPYxuXhwhJaUWiTic2t2yXRVbjZG07TrhxK FIohBzfeJuCgqcAKYb26/OlUlXn21FfDFdPN4OPcIJkd9uPNgDWFhdXaygoQoJswzpg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bTpjODs1; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51B2C606D815; Thu, 5 Nov 2026 19:58:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bTpjODs1 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D5791F0089F; Thu, 5 Nov 2026 19:58:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793908689; bh=qyGxYG8j9RHg2vyof7KTGe46hg815xlN1LVcZ72aA7U=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=bTpjODs1yFu6YRN5fmCYLdyRvgUUVxxbu846Aeqw4iGqXmWrXiCiCnYZPXasoab4i WJUixvU6EfxiEGSTH8p5m6geOsF2FwabLkl8QCKrLRihS90PkxPQvXsImqBoq6fFpI zXPjdUBvvvwz66/+OxS1xiVA7RcTezVhvc4GfvsAwAc8LsSQy1bEWSsOcEBB4lRmfo ocuNeivszTUjoQ2nmvR7p2FOnQgUPyilwusfSiwQhItw9JJ51vQ6W5SqV4sXQcDH2n B5Og2Tn/U2epxnQVrz5GgRaNh5DnwOIPoDojQJuxrNePqy32coheNJG3FyfeA33AJQ zsiW5uI6//0Dw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RESEND v2 19/30] sched/psi: mark the pressure files permanent Reply-To: sashiko-reviews@lists.linux.dev To: "Christian Brauner" Cc: "Linus Torvalds" , "Jann Horn" , "Josef Bacik" , "Chris Mason" , "Jeff Layton" , NeilBrown , "Eric Dumazet" , "Thomas Gleixner" , "Al Viro" , "Jonathan Corbet" , "Christoph Hellwig" , "Greg Kroah-Hartman" , "Joel Granados" , "Kees Cook" , "Jan Kara" , "Jan Kara" , linux-s390@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, linux-m68k@lists.linux-m68k.org, linux-serial@vger.kernel.org, "Takashi Iwai" , linux-ext4@vger.kernel.org, "Chuck Lever" , tytso@mit.edu, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261104-work-procfs-fs-v2-19-319e0f9a8aae@kernel.org> References: <20261104-work-procfs-fs-v2-0-319e0f9a8aae@kernel.org> <20261104-work-procfs-fs-v2-19-319e0f9a8aae@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 19:58:05 +0000 X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > /proc/pressure/* are created when psi initializes and never removed. > Say so with PROC_ENTRY_PERMANENT, procfs then calls into them without > pinning them, like it does for /proc/profile. >=20 > That also takes care of a rule the files bent. psi_write() takes the > seq_file's lock to serialize the triggers. A reader holds that lock > while it copies to userspace, and now that procfs owns the seq_file it > does that with the entry unpinned. So nothing that runs with the entry > pinned may wait for that lock, and psi_write() ran pinned. Nothing ever > waited for it since the files are never removed, but with the files > permanent nothing runs pinned at all. >=20 > Signed-off-by: Christian Brauner (Amutable) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261104-work-procf= s-fs-v2-0-319e0f9a8aae@kernel.org?part=3D19