From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Beshers Date: Wed, 02 May 2007 21:39:48 +0000 Subject: Re: udevd on very large systems: again Message-Id: <46390524.8060305@sgi.com> List-Id: References: <4637D051.7060103@sgi.com> In-Reply-To: <4637D051.7060103@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org Kay Sievers wrote: > On 5/2/07, Kay Sievers wrote: >> On 5/2/07, George Beshers wrote: >> > >> > After some testing the following patch seems safe for dealing with >> computers >> > with more than 500 processors. It occurred to me that it might be >> > easier and >> > just as useful to note when udev is running on a large computer >> (e.g., >= 8p >> > and >= 16Gb of memory) and simply not worry about throttling at >> that point. >> > >> > The patch should apply cleanly against udev-110. >> > >> > Comments welcome. >> >> Looks fine so far, but I still don't see how reading a seq-proc-file >> could miss entries. Are you expecting this to happen? Did you ever see >> this for any of these files? > > If I read linux/fs/proc/proc_misc.c correctly, /proc/stat fills a > buffer of 128kB in one call and passes the data to the file. > > I wonder how long it will take, that you guys hit the 128k limit. :) > > Thanks, > Kay Hmmm... well on the 128p system where I did my testing the size of /proc/stat ranged from 5317 to 5451 (that was with 151 active procs). At that scale 2048 should be OK. BTW. I should have said that the log was generated with a kernel build (make -j 128 or something like that) going. George ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel