From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 E3FDD34C155 for ; Wed, 22 Oct 2025 14:23:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761143013; cv=none; b=XTmGJf14kBYWl3cjptvS0qTPFSlCGUS8/QZTkpg5VEx7riMqkpTamXJYX3XT1A++nkghhRHBPR6BeHY4c01YPzAf9eiUT6kfaUQPNtEeLudTnKp3Vi5MKDgDHR9C/OT1IKZTRFyNLp2mGyMwTyhIXcW7Obs1GBo2VgqDwVVuuEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761143013; c=relaxed/simple; bh=BXbtN2v+8Pnm026y/5JZIdZbNLt1pmFAnwtqv3iUwp8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=o3Fy7YxnvQku8SUXM5shzo4lhTL0DGD7WiCIJW1jcFW1h1lH8bi8NtSATeNXqoW9+31NX4mI4QKiV6GDDFfaxij2brEbt+GnbtW8QUlClfeQilFjtDfEUeSzRdRc8PuKU5Z2xL82MEABsPP1qgT5YN40nfCAe1M6pJ9oA33P6oQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=jODtkpJk; arc=none smtp.client-ip=90.155.50.34 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=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="jODtkpJk" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=8hEdEufKYDlpmRclgwdd1f0mWWuBZqislf9kgj2GKYM=; b=jODtkpJkkWgioRSQsFrDCrEmXF ag0RXtocfkrzgRIZizkNDfQ9dco/iRIcm0ZIfTmNAtQBKbLKwSgOHqFK0Rrj70flsQmfLawIVEKMi GKF/ZKwhyVIf7dRV4SEol0V8X80L9hQ79yjUyKMvTzf1dXJBDZrT5v70IuBLjVWzoJunT1lOHCp1i gqMibQMl46mvkWg7WZ4aQc73I9p/OdC3DbaX6JkjjHJPzD5Kfpj0UFuX74XclOB9r9HVUuudkegUq 5f7hJliVsGVV3abCVspk0+UbdxxLiXcn+yToJdnS5GiC+9cbw8UZCZDPE/0XDsIpURBOyQxLQfuJc s6ox3pUA==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vBZkI-00000007lOE-1nE5; Wed, 22 Oct 2025 14:23:23 +0000 Date: Wed, 22 Oct 2025 15:23:22 +0100 From: Matthew Wilcox To: Joanne Koong Cc: brauner@kernel.org, djwong@kernel.org, hch@infradead.org, bfoster@redhat.com, linux-fsdevel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v2 3/8] iomap: optimize pending async writeback accounting Message-ID: References: <20251021164353.3854086-1-joannelkoong@gmail.com> <20251021164353.3854086-4-joannelkoong@gmail.com> 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: <20251021164353.3854086-4-joannelkoong@gmail.com> On Tue, Oct 21, 2025 at 09:43:47AM -0700, Joanne Koong wrote: > static int iomap_writeback_range(struct iomap_writepage_ctx *wpc, > struct folio *folio, u64 pos, u32 rlen, u64 end_pos, > - bool *wb_pending) > + unsigned *bytes_pending) This makes me nervous. You're essentially saying "we'll never support a folio larger than 2GiB" and I disagree. I think for it to become a practical reality to cache files in 4GiB or larger chunks, we'll need to see about five more doublings in I/O bandwidth. Looking at the progression of PCIe recently that's only about 15 years out. I'd recommend using size_t here to match folio_size().