From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: O_DIRECT on tmpfs (again) Date: Fri, 30 Nov 2012 14:39:40 -0500 Message-ID: References: <50B6830A.20308@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dave Kleikamp , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Richard W.M. Jones" To: Hugh Dickins Return-path: In-Reply-To: (Hugh Dickins's message of "Thu, 29 Nov 2012 17:32:14 -0800 (PST)") Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Hugh Dickins writes: > I've not been entirely convinced that tmpfs needs direct_IO either; > but your links from back then show a number of people who feel that > direct_IO had become mainstream enough to deserve the appearance of > support by tmpfs. One other thing that occurs to me is that, if we fake O_DIRECT, then io_submit will block until the I/O is complete. It shouldn't block for long, sure, but it will still block. I can't say I'm happy about that, given that many applications mix aio+dio, and will now run into some odd behaviour when run against tmpfs. Cheers, Jeff -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org