From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C4C222D948A; Mon, 22 Sep 2025 18:33:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758566038; cv=none; b=EXN6wRfeyhYUUoTw6ZecWT936zEfecLUtDZk6oilERgGMN06LXGrYQvUFRER2aRwP7zmQGrsVx7dHi6pEZhsNGY4pQCCVFY3O8BysGH0qxJ7c4O2zuoufxgWm4QOakDsoEjbPOo6XUtfkkZDjqLOSkW63DTh+s8ZZ9l7/IxsJ0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758566038; c=relaxed/simple; bh=7f6X9BK45s8s/WWNImS47ZKqL25dfIRyq6yzpkvPLqU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XinDM+98GjGfAWU1B9Inr3drcQGfjuXIS/tKeI3FeofAJR2s6p3KzFIKMguSC2MHWQCjqQHoPxe/Q8OvLs4MfDTadfXF2wdE90XjNpohmHQGGiBO1FH5XY0zsI65VkUy9hRZgbACGxZIfh5t3eUkdm9emETi1upHONDwhJ4zAdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=f1iGZvsI; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="f1iGZvsI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Pk0qXAy77S9S9BN6W/egzghhkLeJ2kMDcymJHNW+Geo=; b=f1iGZvsI7MMMKm6AlFSw/0gMvE 4kXNPJt5mE/WQfL5BfjwBu3uKLri5sv1tm7/Z22oRirtItJW4IDW9fNBItMCI4/xFMmQb0r23sMBs DXihmc7jXuoRR4WLkdIZZT9pnUhnFRJpeELTmHe8Vkc72WbpFYLQyxeAZxE290/KrSOOwX794+06w SXMUlvRPSC+q6DXiXaqZ2N6J4ihxbCdjzzjKxuxjp0kDrVtgKMiXc11Nl5f4z8026GSLnl8nfNVm0 OsqTc9nDq1piwbGGfv/lZYpnDroXXhMfxjZ0ZR9+YcoJyGXaW0tCo856iVH3VkeP0scpzGAj+Lwal CILooQbw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v0lMI-0000000BFwN-46U7; Mon, 22 Sep 2025 18:33:54 +0000 Date: Mon, 22 Sep 2025 11:33:54 -0700 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Joanne Koong , brauner@kernel.org, miklos@szeredi.hu, hch@infradead.org, hsiangkao@linux.alibaba.com, linux-block@vger.kernel.org, gfs2@lists.linux.dev, linux-fsdevel@vger.kernel.org, kernel-team@meta.com, linux-xfs@vger.kernel.org, linux-doc@vger.kernel.org, Ritesh Harjani , Matthew Wilcow Subject: Re: [PATCH v3 10/15] iomap: add bias for async read requests Message-ID: References: <20250916234425.1274735-1-joannelkoong@gmail.com> <20250916234425.1274735-11-joannelkoong@gmail.com> <20250918223018.GY1587915@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20250918223018.GY1587915@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Thu, Sep 18, 2025 at 03:30:18PM -0700, Darrick J. Wong wrote: > > + iomap_start_folio_read(folio, 1); > > I wonder, could you achieve the same effect by elevating > read_bytes_pending by the number of bytes that we think we have to read, > and subtracting from it as the completions come in or we decide that no > read is necessary? Weren't we going to look into something like that anyway to stop the read code from building bios larger than the map to support the extN boundary conditions? I'm trying to find the details of that, IIRC willy suggested it. Because once we touch this area for non-trivial changes it might be a good idea to get that done, or at least do the prep work.