From: Peter Zijlstra <peterz@infradead.org>
To: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Cc: Stephane Eranian <eranian@google.com>,
linux-kernel@vger.kernel.org, mingo@elte.hu, ak@linux.intel.com,
jolsa@redhat.com, zheng.z.yan@intel.com
Subject: Re: [PATCH 5/9] perf/x86: implement cross-HT corruption bug workaround
Date: Thu, 5 Jun 2014 16:14:25 +0200 [thread overview]
Message-ID: <20140605141425.GB3588@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20140605141150.GL6758@twins.programming.kicks-ass.net>
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On Thu, Jun 05, 2014 at 04:11:50PM +0200, Peter Zijlstra wrote:
> > > x86_schedule_event()
> > > ->start_scheduling()
> > > spin_lock()
> > > ->get_event_constraints()
> > > intel_get_excl_constraints()
> > > kmalloc(.gfp=GFP_KERNEL)
> > >
> > > How can that ever work?
>
> > Are you saying it is illegal to call kmalloc() from
> > this context?
>
> Nobody will come and arrest you for it, so no. Broken though. GFP_KERNEL
> will attempt to sleep to wait for reclaim, and you're holding a
> spinlock.
Furthermore, even GFP_ATOMIC shouldn't be used because these are/should
be raw_spinlocks and the zone->lock is a regular spinlock.
So please look into the preallocation thing.
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next prev parent reply other threads:[~2014-06-05 14:14 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-04 21:34 [PATCH 0/9] perf/x86: implement HT counter corruption workaround Stephane Eranian
2014-06-04 21:34 ` [PATCH 1/9] perf,x86: rename er_flags to flags Stephane Eranian
2014-06-04 21:34 ` [PATCH 2/9] pref/x86: vectorize cpuc->kfree_on_online Stephane Eranian
2014-06-04 21:34 ` [PATCH 3/9] perf/x86: add 3 new scheduling callbacks Stephane Eranian
2014-06-04 21:34 ` [PATCH 4/9] perf/x86: add cross-HT counter exclusion infrastructure Stephane Eranian
2014-06-05 7:47 ` Peter Zijlstra
2014-06-05 10:51 ` Stephane Eranian
2014-06-05 8:04 ` Peter Zijlstra
2014-06-05 13:36 ` Maria Dimakopoulou
2014-06-05 8:29 ` Peter Zijlstra
2014-06-05 21:33 ` Andi Kleen
2014-06-05 21:38 ` Stephane Eranian
2014-06-10 11:53 ` Stephane Eranian
2014-06-10 12:26 ` Peter Zijlstra
2014-06-04 21:34 ` [PATCH 5/9] perf/x86: implement cross-HT corruption bug workaround Stephane Eranian
2014-06-05 13:38 ` Peter Zijlstra
2014-06-05 13:42 ` Peter Zijlstra
2014-06-05 13:48 ` Peter Zijlstra
2014-06-05 14:01 ` Maria Dimakopoulou
2014-06-05 14:04 ` Borislav Petkov
2014-06-05 14:11 ` Peter Zijlstra
2014-06-05 14:14 ` Peter Zijlstra [this message]
2014-06-05 14:24 ` Maria Dimakopoulou
2014-06-05 14:04 ` Peter Zijlstra
2014-06-05 14:15 ` Stephane Eranian
2014-06-05 14:21 ` Peter Zijlstra
2014-06-05 14:26 ` Stephane Eranian
2014-06-05 14:31 ` Peter Zijlstra
2014-06-05 15:31 ` Stephane Eranian
2014-06-04 21:34 ` [PATCH 6/9] perf/x86: enforce HT bug workaround for SNB/IVB/HSW Stephane Eranian
2014-06-04 21:34 ` [PATCH 7/9] perf/x86: enforce HT bug workaround with PEBS " Stephane Eranian
2014-06-04 21:34 ` [PATCH 8/9] perf/x86: fix intel_get_event_constraints() for dynamic constraints Stephane Eranian
2014-06-04 21:34 ` [PATCH 9/9] perf/x86: add syfs entry to disable HT bug workaround Stephane Eranian
2014-06-05 8:32 ` Matt Fleming
2014-06-05 9:29 ` Stephane Eranian
2014-06-05 10:01 ` Matt Fleming
2014-06-05 10:19 ` Stephane Eranian
2014-06-05 11:16 ` Matt Fleming
2014-06-05 12:02 ` Stephane Eranian
2014-06-05 13:27 ` Borislav Petkov
2014-06-05 13:42 ` Stephane Eranian
2014-06-05 14:03 ` Borislav Petkov
2014-06-05 14:45 ` Maria Dimakopoulou
2014-06-05 15:17 ` Borislav Petkov
2014-06-05 16:39 ` Maria Dimakopoulou
2014-06-05 16:47 ` Stephane Eranian
2014-06-05 16:52 ` Borislav Petkov
2014-06-05 18:00 ` Maria Dimakopoulou
2014-06-05 23:29 ` Andi Kleen
2014-06-06 8:28 ` Matt Fleming
2014-06-05 12:50 ` Peter Zijlstra
2014-06-05 12:55 ` Stephane Eranian
2014-06-05 12:59 ` Peter Zijlstra
2014-06-05 13:16 ` Stephane Eranian
2014-06-05 13:26 ` Peter Zijlstra
2014-06-05 13:19 ` Peter Zijlstra
2014-06-05 13:26 ` Stephane Eranian
2014-06-04 22:28 ` [PATCH 0/9] perf/x86: implement HT counter corruption workaround Andi Kleen
2014-06-05 12:45 ` Stephane Eranian
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