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 9837214A619; Wed, 22 Jan 2025 06:08:11 +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=1737526093; cv=none; b=BKA6bSlJnUC9tKDLMXKvzKiMjTwKHFuFeveg8zh9OMgLibaVWHKbpQzGjYWxuyoLg7rL2XR55KNBcmryQYt06BsKuA0fxFayYO/sQUjCboejY1/kWhddu4+G4jo37E74BiWcJe+rznuCPQV8thorUveRMRHF7onRSIW9/OUBv2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737526093; c=relaxed/simple; bh=KjJMs8fHVwKHv6OEfexa9LSO1lfvBeAQDSndd5UClnU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Sjz1lFrdk9L1z0IcgPzdI4QvjcDQ6EJUh6VY9Acj3Tz2nBDOS7Pqw9yKYze0rdEDzWZx7GO5JaJ+NfSixWcjQolnTOh6gkvORuRoms76soo6V4dBvcjF1YF088MNxWD8uOPM0+i6FgQgjwCel9vkGYzJMJWBP0ncakTnKMVBbZU= 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=lGzK/p2a; 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="lGzK/p2a" 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=esCE0uoIt2v9CGg9foXrw4Ks2MQtiIQdLM2LCx2319Y=; b=lGzK/p2ahqdQfJRAUt7dvNrjBT EE99qi+u4vGdUSqzRVDlyfSdNdrsE5XWjNtTrt9jMn0FKoxFo4yhnWHD9tH6vTkftD5fKyGfD5t4W wN90pWOopUXJlQda8fnOAFANxzYGUqSCGImm3zFWR2mKHjsg+Sl0fiDsKj+vf4xbjSKRN/Kmmv4JQ 6DBURcXUYx5d1FyDzDs0T3vzM3F07HKxaWCkc3+L4AGr83PC8UxNomi8PR81qwdbeKNX8twJsCZoe xvx2SwgvJrne01qzvO3mleqSkGCwCYgiVojWtN+pKO8ZNvSJe7Ps5LDlB+rDHLH/371/kBjj4E8fB IVeTEPAg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1taTuM-00000009STs-08pS; Wed, 22 Jan 2025 06:08:10 +0000 Date: Tue, 21 Jan 2025 22:08:10 -0800 From: Christoph Hellwig To: Dave Chinner Cc: Amir Goldstein , Christoph Hellwig , Brian Foster , "Darrick J. Wong" , Chi Zhiling , cem@kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, Chi Zhiling , John Garry Subject: Re: [PATCH] xfs: Remove i_rwsem lock in buffered read Message-ID: References: <20250108173547.GI1306365@frogsfrogsfrogs> <20250113024401.GU1306365@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-kernel@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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Sat, Jan 18, 2025 at 09:19:15AM +1100, Dave Chinner wrote: > And, quite frankly, the fact the bcachefs solution also covers AIO > DIO in flight (which i_rwsem based locking does not!) means it is a > more robust solution than trying to rely on racy i_dio_count hacks > and folio residency in the page cache... The original i_rwsem (still i_iolock then) scheme did that, but the core locking maintainers asked us to remove the non-owner unlocks, so I did that. It turns out later we got officially sanctioned non-owner unlocks, so we could have easily add this back. I did that 5 years ago, but reception was lukewarm: http://git.infradead.org/?p=users/hch/xfs.git;a=shortlog;h=refs/heads/i_rwsem-non_owner