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 046A64C98 for ; Sat, 1 Mar 2025 00:19:09 +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=1740788350; cv=none; b=bqoEAOMsgo1y3cpb6MTuCWLIS7TsWIi9DIT2ktrVMbAa9YPXwEPz4WsPxLAfuWUprodrU4urnnyGm7YxWpB+2MyLYRnWFaoK+aLLEsEIRSXFQHDthaSHcK0jdCebKHBZH5Pcla1kiFQVy1q8q4JIW+2ZYiLPuKH6W+yNixJnNzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740788350; c=relaxed/simple; bh=dPdLstrfbT7/S+KIZ0mekeNancQ5apILDGFFLCPIHBQ=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=t7IqedzG0/iOL2TqDltdPgh4xinXbAp8EQOcBRsLPyTWarsSiHmHA5eaMqYbnvZ7WBlbuxK+tOjYpfUvJPgah3+FguvKQXczXfXauImR/OVOTL9owAzezhwmhxAt8pt9O5FhAjji6lWOmahAjAt3tGgiuS4CHJ4/F6HX9Bqv1yY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PMhBQ3hf; 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="PMhBQ3hf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50B10C4CED6; Sat, 1 Mar 2025 00:19:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740788349; bh=dPdLstrfbT7/S+KIZ0mekeNancQ5apILDGFFLCPIHBQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PMhBQ3hfOF8bxEHjokK0+pWsCK/8EohL1rQM68MLmtHUzsmbMwnAaOpx3fesyOvKH u4D7JSrRj5i1Zb8CmLmhe8EB10I6eRVU/atdX4B5V6nUDSV+Zhf1siqEDe0CGbGNqF b/ZkrH/d7spGFpWappAXcYL52yjH7Eew11M3MY1P+n1u05sBLfpR8W4kF7EU9sSuQ3 4hA2edSGyt3thDeiOTxxxFgu9+B56pED4vn50FDch8EdTL+yftHd0lY5/pN+fDwImb HNM2XoMczWcseNdiAqQnRFq2h0cExHvHoNb3qP0MdNEuL13KZTnF/2rvSnj+INMisa VE7JMu7cvOWKA== Date: Fri, 28 Feb 2025 16:19:08 -0800 From: Jakub Kicinski To: allison.henderson@oracle.com Cc: netdev@vger.kernel.org Subject: Re: [PATCH 1/6] net/rds: Avoid queuing superfluous send and recv work Message-ID: <20250228161908.3d7c997c@kernel.org> In-Reply-To: <20250227042638.82553-2-allison.henderson@oracle.com> References: <20250227042638.82553-1-allison.henderson@oracle.com> <20250227042638.82553-2-allison.henderson@oracle.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 26 Feb 2025 21:26:33 -0700 allison.henderson@oracle.com wrote: > + /* clear_bit() does not imply a memory barrier */ > + smp_mb__before_atomic(); > + clear_bit(RDS_SEND_WORK_QUEUED, &cp->cp_flags); > + /* clear_bit() does not imply a memory barrier */ > + smp_mb__after_atomic(); I'm guessing the comments were added because checkpatch asked for them. The comments are supposed to indicate what this barrier pairs with. I don't see the purpose of these barriers, please document..