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 0AC1A16DED5; Tue, 10 Sep 2024 17:19:33 +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=1725988774; cv=none; b=spN6539eVio1XJGdYfSvlkymvgoisIJ4OrICJOalA9I30sAmMqh2oL6Ma/LxBkILoBx+k2FEEHYMHUvejAPn5grp6p3CUbruSjR5A3eOF1VsWao7ujyKzHXUqu2NFf0J+8W/Svr+Fn4qVQnxh/cev8KdnbGqS2Bq0OX87Nb6nMs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725988774; c=relaxed/simple; bh=Jc2puORiYOo6/PGjGJmiUGrpWVJCAW6zaHCUDlRoGBY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Hh2LkETeYIM1DYd2XglQWR94N4l8PJ5JrVryaeV7jpI5T1lnmHnolwh+NFnbn7wq2BgBElWAeD+AAPObHwjRLYs5kfQIjdeyE7rXp4lvuMWw6lSOAC1bDuRny0YJIH4yvt0awhwRuqFHYWneOpL7atzBw2KPBlmtVvQfVxVNV6o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YranuHzJ; 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="YranuHzJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5B28C4CEC3; Tue, 10 Sep 2024 17:19:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725988773; bh=Jc2puORiYOo6/PGjGJmiUGrpWVJCAW6zaHCUDlRoGBY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YranuHzJ9O+PkhMM3y3l1AnOorUXlqQcyQwRVZS/I2MXrKLTxkSEksGcflLatAMsC 4/kt+ZrS9ugZZ9yVCSCvuhUSfP0poZrCz3oE97PAhK2UkTim4klKquEY+Kx01d9X9P MvCOFl3/enrM4UlnoDdDOSM9NgREXE+5+P7lrmPf/5NK5SLZsdp+OL80v9z7QjeYgd M85c3CEG05kKH67y3PR4hAuE1wgiEMe8n3A2InyDWc/2cno2zny4TBHcSFAzSp+RPw qv2w+atYYdvYmpvf4/NkCptgGCEREaftSw2v9ngdba8BKIEDs4cwpRrqe0+7h6BlnY ghHs1MsCCVZVQ== Date: Tue, 10 Sep 2024 11:19:30 -0600 From: Keith Busch To: Christoph Hellwig Cc: Keith Busch , axboe@kernel.dk, martin.petersen@oracle.com, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, sagi@grimberg.me Subject: Re: [PATCHv3 09/10] blk-integrity: consider entire bio list for merging Message-ID: References: <20240904152605.4055570-1-kbusch@meta.com> <20240904152605.4055570-10-kbusch@meta.com> <20240910154843.GI23805@lst.de> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240910154843.GI23805@lst.de> On Tue, Sep 10, 2024 at 05:48:43PM +0200, Christoph Hellwig wrote: > On Wed, Sep 04, 2024 at 08:26:04AM -0700, Keith Busch wrote: > > From: Keith Busch > > > > If a bio is merged to a req, the entire bio list is merged, so don't > > temporarily unchain it when counting segments for consideration. > > As far as I can tell we never do merge decisions on bio lists. If > bi_next is non-NULL here it probably is due to scheduler lists or > something like it. I think bi_next is always NULL, so the unlinking should be a no-op. But just in case it isn't, the current unlinking will get the wrong segment count from the resulting merge.