From: "Rafael J. Wysocki" <rafael@kernel.org> To: Peter Zijlstra <peterz@infradead.org> Cc: "Singh, Balbir" <sblbir@amazon.com>, "Valentin, Eduardo" <eduval@amazon.com>, "boris.ostrovsky@oracle.com" <boris.ostrovsky@oracle.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "Agarwal, Anchal" <anchalag@amazon.com>, "Woodhouse, David" <dwmw@amazon.co.uk>, "vkuznets@redhat.com" <vkuznets@redhat.com>, "sstabellini@kernel.org" <sstabellini@kernel.org>, "tglx@linutronix.de" <tglx@linutronix.de>, "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, "Woodhouse@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com" <Woodhouse@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "jgross@suse.com" <jgross@suse.com>, "pavel@ucw.cz" <pavel@ucw.cz>, "axboe@kernel.dk" <axboe@kernel.dk>, "x86@kernel.org" <x86@kernel.org>, "roger.pau@citrix.com" <roger.pau@citrix.com>, "hpa@zytor.com" <hpa@zytor.com>, "rjw@rjwysocki.net" <rjw@rjwysocki.net>, "mingo@redhat.com" <mingo@redhat.com>, "Kamata, Munehisa" <kamatam@amazon.com>, "bp@alien8.de" <bp@alien8.de>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "konrad.wilk@oracle.co" <konrad.wilk@oracle.co>, "len.brown@intel.com" <len.brown@intel.com>, "davem@davemloft.net" <davem@davemloft.net>, "fllinden@amaozn.com" <fllinden@amaozn.com>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org> Subject: Re: [RFC PATCH V2 11/11] x86: tsc: avoid system instability in hibernation Date: Mon, 13 Jan 2020 22:50:59 +0100 [thread overview] Message-ID: <CAJZ5v0jv+5aLY3N4wFSitu61o9S8tJWEWGGn1Xyw-P82_TwFdQ@mail.gmail.com> (raw) In-Reply-To: <20200113124247.GG2827@hirez.programming.kicks-ass.net> On Mon, Jan 13, 2020 at 1:43 PM Peter Zijlstra <peterz@infradead.org> wrote: > > On Mon, Jan 13, 2020 at 11:43:18AM +0000, Singh, Balbir wrote: > > For your original comment, just wanted to clarify the following: > > > > 1. After hibernation, the machine can be resumed on a different but compatible > > host (these are VM images hibernated) > > 2. This means the clock between host1 and host2 can/will be different > > > > In your comments are you making the assumption that the host(s) is/are the > > same? Just checking the assumptions being made and being on the same page with > > them. > > I would expect this to be the same problem we have as regular suspend, > after power off the TSC will have been reset, so resume will have to > somehow bridge that gap. I've no idea if/how it does that. In general, this is done by timekeeping_resume() and the only special thing done for the TSC appears to be the tsc_verify_tsc_adjust(true) call in tsc_resume(). > I remember some BIOSes had crazy TSC ideas for suspend2ram, and we grew > tsc_restore_sched_clock_state() for it. > > Playing crazy games like what you're doing just isn't it though. Right.
WARNING: multiple messages have this Message-ID (diff)
From: "Rafael J. Wysocki" <rafael@kernel.org> To: Peter Zijlstra <peterz@infradead.org> Cc: "konrad.wilk@oracle.co" <konrad.wilk@oracle.co>, "Valentin, Eduardo" <eduval@amazon.com>, "len.brown@intel.com" <len.brown@intel.com>, "x86@kernel.org" <x86@kernel.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "pavel@ucw.cz" <pavel@ucw.cz>, "hpa@zytor.com" <hpa@zytor.com>, "boris.ostrovsky@oracle.com" <boris.ostrovsky@oracle.com>, "sstabellini@kernel.org" <sstabellini@kernel.org>, "fllinden@amaozn.com" <fllinden@amaozn.com>, "Kamata, Munehisa" <kamatam@amazon.com>, "mingo@redhat.com" <mingo@redhat.com>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>, "Singh, Balbir" <sblbir@amazon.com>, "axboe@kernel.dk" <axboe@kernel.dk>, "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>, "Agarwal, Anchal" <anchalag@amazon.com>, "bp@alien8.de" <bp@alien8.de>, "tglx@linutronix.de" <tglx@linutronix.de>, "jgross@suse.com" <jgross@suse.com>, "netdev@vger.kernel.org" <netdev@vger.kernel.org>, "Woodhouse@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com" <Woodhouse@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com>, "rjw@rjwysocki.net" <rjw@rjwysocki.net>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "vkuznets@redhat.com" <vkuznets@redhat.com>, "davem@davemloft.net" <davem@davemloft.net>, "Woodhouse, David" <dwmw@amazon.co.uk>, "roger.pau@citrix.com" <roger.pau@citrix.com> Subject: Re: [Xen-devel] [RFC PATCH V2 11/11] x86: tsc: avoid system instability in hibernation Date: Mon, 13 Jan 2020 22:50:59 +0100 [thread overview] Message-ID: <CAJZ5v0jv+5aLY3N4wFSitu61o9S8tJWEWGGn1Xyw-P82_TwFdQ@mail.gmail.com> (raw) In-Reply-To: <20200113124247.GG2827@hirez.programming.kicks-ass.net> On Mon, Jan 13, 2020 at 1:43 PM Peter Zijlstra <peterz@infradead.org> wrote: > > On Mon, Jan 13, 2020 at 11:43:18AM +0000, Singh, Balbir wrote: > > For your original comment, just wanted to clarify the following: > > > > 1. After hibernation, the machine can be resumed on a different but compatible > > host (these are VM images hibernated) > > 2. This means the clock between host1 and host2 can/will be different > > > > In your comments are you making the assumption that the host(s) is/are the > > same? Just checking the assumptions being made and being on the same page with > > them. > > I would expect this to be the same problem we have as regular suspend, > after power off the TSC will have been reset, so resume will have to > somehow bridge that gap. I've no idea if/how it does that. In general, this is done by timekeeping_resume() and the only special thing done for the TSC appears to be the tsc_verify_tsc_adjust(true) call in tsc_resume(). > I remember some BIOSes had crazy TSC ideas for suspend2ram, and we grew > tsc_restore_sched_clock_state() for it. > > Playing crazy games like what you're doing just isn't it though. Right. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2020-01-13 21:51 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-07 23:45 [RFC PATCH V2 11/11] x86: tsc: avoid system instability in hibernation Anchal Agarwal 2020-01-07 23:45 ` [Xen-devel] " Anchal Agarwal 2020-01-08 10:50 ` Peter Zijlstra 2020-01-08 10:50 ` [Xen-devel] " Peter Zijlstra 2020-01-10 15:35 ` Eduardo Valentin 2020-01-10 15:35 ` [Xen-devel] " Eduardo Valentin 2020-01-13 10:16 ` Peter Zijlstra 2020-01-13 10:16 ` [Xen-devel] " Peter Zijlstra 2020-01-13 11:43 ` Singh, Balbir 2020-01-13 11:43 ` [Xen-devel] " Singh, Balbir 2020-01-13 11:43 ` Singh, Balbir 2020-01-13 11:48 ` Rafael J. Wysocki 2020-01-13 11:48 ` [Xen-devel] " Rafael J. Wysocki 2020-01-13 11:48 ` Rafael J. Wysocki 2020-01-13 12:42 ` Peter Zijlstra 2020-01-13 12:42 ` [Xen-devel] " Peter Zijlstra 2020-01-13 12:42 ` Peter Zijlstra 2020-01-13 21:50 ` Rafael J. Wysocki [this message] 2020-01-13 21:50 ` [Xen-devel] " Rafael J. Wysocki 2020-01-13 21:50 ` Rafael J. Wysocki 2020-01-13 23:30 ` Rafael J. Wysocki 2020-01-13 23:30 ` [Xen-devel] " Rafael J. Wysocki 2020-01-13 23:30 ` Rafael J. Wysocki 2020-01-14 19:29 ` Anchal Agarwal 2020-01-14 19:29 ` [Xen-devel] " Anchal Agarwal 2020-01-22 20:07 ` Anchal Agarwal 2020-01-22 20:07 ` [Xen-devel] " Anchal Agarwal 2020-01-23 16:27 ` Boris Ostrovsky 2020-01-23 16:27 ` [Xen-devel] " Boris Ostrovsky 2020-01-13 13:01 ` Andrew Cooper 2020-01-13 13:01 ` Andrew Cooper 2020-01-13 13:01 ` Andrew Cooper 2020-01-13 13:54 ` David Woodhouse 2020-01-13 13:54 ` David Woodhouse 2020-01-13 13:54 ` David Woodhouse 2020-01-13 15:02 ` Singh, Balbir 2020-01-13 15:02 ` Singh, Balbir 2020-01-13 15:02 ` Singh, Balbir
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