From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: Issue with 252c651a4c85 ("blk-cgroup: stop using seq_get_buf") Date: Tue, 17 May 2022 08:11:52 +0200 Message-ID: <20220517061152.GA4789@lst.de> References: Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Khazhy Kumykov Cc: Tejun Heo , Jens Axboe , Christoph Hellwig , linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, w.bumiller-YTcQvvOqK21BDgjK7y7TUQ@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Thu, May 12, 2022 at 03:42:54PM -0700, Khazhy Kumykov wrote: > I can see in the latest tip, if we have devices with no statistics, > we'll print the maj:min and then nothing else, which can end up > looking weird, (e.g. like below.) I see that in older kernels, we > avoided printing the device name at all if there were no stats, and it > looks like this behavior was silently broken by 252c651a4c85 > ("blk-cgroup: stop using seq_get_buf"), where before we prepared the > whole line then decided at the end whether to commit it or not. > > I do see a patch "blk-cgroup: always terminate io.stat lines" that > addresses this by just unconditionally printing the newline (though it > looks like that patch never landed). It should really go in, I just sent a ping for it.