From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D52F72046A2 for ; Wed, 22 Jan 2025 09:09:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737536997; cv=none; b=Ep4AYelN/M1i7pJNR4fo2kgzCS76uXe0qrqv39lpgBLzYHX+WZTUDBjWU1TJGEoDNawPvVXyHFw7xVTqy6l09CNg4CKyr1I7k5I5wRT7mV+YSo76h4wMvAHnLFYeUk3iUOOEA3yGkonIDjtPRs+Tkl0ktDu873yJEH1XQ73PRuM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737536997; c=relaxed/simple; bh=VtXv6DLbXfaDyqUNqHj2wss1bquCwsI/gBTXMJPeteg=; h=Content-Type:MIME-Version:In-Reply-To:References:Subject:From:Cc: To:Date:Message-ID; b=qOVD7xjkkd9Krw8cVxsEYETONFH/efjUpWNTYGu8Q11MGjupnPZtBcqHd7f/goFmgSvXqghtRzJDMAXkEvVknYtz6Y76+QzROl+FeQprMR8+uQctkoPqrG5h5uR4vqqAdrHmKvSuZKWUVCFu40xoogOxT6HPwfbszFQzeReqms4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aZ7BUFyJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aZ7BUFyJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6378C4CED6; Wed, 22 Jan 2025 09:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737536997; bh=VtXv6DLbXfaDyqUNqHj2wss1bquCwsI/gBTXMJPeteg=; h=In-Reply-To:References:Subject:From:Cc:To:Date:From; b=aZ7BUFyJ4bD/DsP68dlsM7++Lh0dpclm0+mapCZOkdREAgFp3nyWY/87lVuCYikWk d054XMqpYYSfaRKsM0aSZiruilcSzLir73/Trkkrs1uNDyWWVPHMLWX2RKWg2uhZXH IlsBOSo14WSUZIgaoeWGI1zhp9S2GEvcXnyfN+gRlH2z9vO7TzuOAc9xUXk4UQZeHY i4zMzCa04StFq3KeVNF1406CFOJk+ytjlr3XcNtFsrW8q6ia8k2AUWvxXUkhPXi026 dDrcwbnmnQeqGUo63lNpxdM3k5pnBO/kqHlQu2sx10vl+z29CRgXIiGdjbzVCh8Mnk XBTKms9oKC5Mw== Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20250122095024.35c78381@device-291.home> References: <20250117102612.132644-1-atenart@kernel.org> <20250122095024.35c78381@device-291.home> Subject: Re: [PATCH net-next 0/4] net-sysfs: remove the rtnl_trylock/restart_syscall construction From: Antoine Tenart Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, stephen@networkplumber.org, gregkh@linuxfoundation.org, netdev@vger.kernel.org, Christophe Leroy To: Maxime Chevallier Date: Wed, 22 Jan 2025 10:09:54 +0100 Message-ID: <173753699410.42919.17052319601873170277@kwain> Quoting Maxime Chevallier (2025-01-22 09:50:24) > On Fri, 17 Jan 2025 11:26:07 +0100 > Antoine Tenart wrote: >=20 > > The series initially aimed at improving spins (and thus delays) while > > accessing net sysfs under rtnl lock contention[1]. The culprit was the > > trylock/restart_syscall constructions. There wasn't much interest at the > > time but it got traction recently for other reasons (lowering the rtnl > > lock pressure). > >=20 > > Since the RFC[1]: > >=20 > > - Limit the breaking of the sysfs protection to sysfs_rtnl_lock() only > > as this is not needed in the whole rtnl locking section thanks to the > > additional check on dev_isalive(). This simplifies error handling as > > well as the unlocking path. > > - Used an interruptible version of rtnl_lock, as done by Jakub in > > his experiments. > > - Removed a WARN_ONCE_ONCE call [Greg]. > > - Removed explicit inline markers [Stephen]. > >=20 > > Most of the reasoning is explained in comments added in patch 1. This > > was tested by stress-testing net sysfs attributes (read/write ops) while > > adding/removing queues and adding/removing veths, all in parallel. I > > also used an OCP single node cluster, spawning lots of pods. > >=20 > > Thanks, > > Antoine > >=20 > > [1] https://lore.kernel.org/all/20231018154804.420823-1-atenart@kernel.= org/T/ >=20 > Thanks for that work, it looks like this would address this problem > faced recently by Christophe (in CC) : >=20 > https://lore.kernel.org/netdev/d416a14ec38c7ba463341b83a7a9ec6ccc435246.1= 734419614.git.christophe.leroy@csgroup.eu/ That's likely given the diff, I actually wanted to Cc him here but looks like I forgot... Thanks for doing so.