From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1ZsXqp-0003aR-9n for user-mode-linux-devel@lists.sourceforge.net; Sat, 31 Oct 2015 15:13:51 +0000 Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1ZsXqn-0001UB-Bg for user-mode-linux-devel@lists.sourceforge.net; Sat, 31 Oct 2015 15:13:51 +0000 References: <1445416947-824802-1-git-send-email-aivanov@brocade.com> <562D236E.7020108@kot-begemot.co.uk> <562DFC90.9030308@nod.at> <5631BB4E.4010301@kot-begemot.co.uk> <1446304232.3238.8.camel@m3y3r.de> From: Richard Weinberger Message-ID: <5634DAA4.70308@nod.at> Date: Sat, 31 Oct 2015 16:13:40 +0100 MIME-Version: 1.0 In-Reply-To: <1446304232.3238.8.camel@m3y3r.de> List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net Subject: Re: [uml-devel] [PATCH v3] um: Switch clocksource to hrtimers To: Thomas Meyer , Richard Weinberger , Anton Ivanov Cc: "user-mode-linux-devel@lists.sourceforge.net" Am 31.10.2015 um 16:10 schrieb Thomas Meyer: > Am Samstag, den 31.10.2015, 14:54 +0100 schrieb Richard Weinberger: >> On Thu, Oct 29, 2015 at 7:23 AM, Anton Ivanov >> wrote: >>> I got the first patchset to build, it works very well on a single >>> core >>> host or with CPU pinning of the UML - the performance gain is > >>> 25%. >>> >>> However, I introduced a race somewhere along the way - it crashes >>> UML >>> reliably if you do not pin CPUs. >> >> How does the crash look like? >> I see also an issue with that patch, after UML has an uptime of a few >> minutes >> a task which does nanosleep() will never wake up. >> >> [<000000006001a29d>] __switch_to+0x53/0x82 >> [<00000000602995d2>] __schedule+0x2f4/0x3f7 >> [<0000000060299751>] schedule+0x7c/0x95 >> [<000000006029b871>] do_nanosleep+0x8b/0x134 >> [<0000000060068a41>] hrtimer_nanosleep+0xb2/0x15a >> [<0000000060068b90>] SyS_nanosleep+0xa7/0xbf >> [<000000006001d492>] handle_syscall+0x6a/0x84 >> [<00000000600304a8>] userspace+0x3d8/0x463 >> [<000000006001a180>] fork_handler+0x85/0x87 >> [] 0xffffffffffffffff >> > > Hi, > > is this crash/hang about the "switch clocksource to hrtimers" patch or > about the next patch that improves UBD improvements? Whoops. Forgot to mention. "switch clocksource to hrtimers" is the bad one. So far I can trigger the issue only by starting UML and waiting some time. Thanks, //richard ------------------------------------------------------------------------------ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel