From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Moyer Subject: Re: [HELP]: about aio+dio Date: Wed, 27 Aug 2014 09:38:03 -0400 Message-ID: References: <6AA21C22F0A5DA478922644AD2EC308C8B7D05@SHSMSX101.ccr.corp.intel.com> <20140820184346.GK429@lenny.home.zabbo.net> <6AA21C22F0A5DA478922644AD2EC308C8B8016@SHSMSX101.ccr.corp.intel.com> <20140821165846.GB7116@lenny.home.zabbo.net> <6AA21C22F0A5DA478922644AD2EC308C8B850F@SHSMSX101.ccr.corp.intel.com> <20140826185218.GA12827@lenny.home.zabbo.net> <6AA21C22F0A5DA478922644AD2EC308C8B8D17@SHSMSX101.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Zach Brown , "viro\@zeniv.linux.org.uk" , Sage Weil , Mark Kirkwood , "linux-aio\@kvack.org" , "linux-fsdevel\@vger.kernel.org" To: "Ma\, Jianpeng" Return-path: In-Reply-To: <6AA21C22F0A5DA478922644AD2EC308C8B8D17@SHSMSX101.ccr.corp.intel.com> (Jianpeng Ma's message of "Wed, 27 Aug 2014 00:34:44 +0000") Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org "Ma, Jianpeng" writes: > For aio+directio: > After io_submit, the content in request-queue of block-device. Maybe. It might be in the per-cpu plug list, or in the elevator's queues. > In blkdev_fsync(), it will cal blkdev_issue_flush. This operation make > all request to disk. blkdev_issue_flush send a FLUSH to the device. It does nothing to re-order existing requests in the queue. Thus, as Zach said, if you want to ensure data is on stable media, then you should wait for the I/O to complete and then issue the fsync. Cheers, Jeff -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org