From: Jim Keniston <jkenisto@linux.vnet.ibm.com>
To: Josh Stone <jistone@redhat.com>
Cc: Mark Wielaard <mjw@redhat.com>,
systemtap@sourceware.org, dsmith@redhat.com
Subject: Re: Fixed PR13146 by not allowing memory allocations to sleep (Was: [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-1.6-151-g8e794e9)
Date: Tue, 27 Sep 2011 23:01:00 -0000 [thread overview]
Message-ID: <1317164453.3979.9.camel@localhost> (raw)
In-Reply-To: <4E82481E.8060502@redhat.com>
On Tue, 2011-09-27 at 15:03 -0700, Josh Stone wrote:
> On 09/27/2011 07:52 AM, Mark Wielaard wrote:
> > Hi David,
> >
> > On Thu, 2011-09-01 at 14:39 +0000, dsmith@sourceware.org wrote:
> >> commit 8e794e9dfeea5a48b84442b92dea6c17b9ef75d1
> >> Author: David Smith <dsmith@redhat.com>
> >> Date: Thu Sep 1 09:39:15 2011 -0500
> >>
> >> Fixed PR13146 by not allowing memory allocations to sleep.
> >>
> >> * runtime/alloc.c: Turn off __GFP_WAIT when allocating memory.
> >> * runtime/transport/ring_buffer.c (__stp_alloc_ring_buffer): Ditto.
> >> * runtime/counter.c (_stp_counter_init): Handles memory allocation failure
> >> better.
> >> * runtime/task_finder.c (__stp_call_mmap_callbacks_with_addr): Better
> >> cleanup if memory allocation fails.
> >
> > Sorry for the late reply. But I am suspecting this commit of causing
> > accasional (though not very frequent) test failures that say:
> > ERROR: context (size 8352) allocation failed
> >
> > I suspect that is caused because the context is one of the larger
> > allocations at systemtap_module_init time. And because we are no longer
> > allowed to GFP_WAIT it is more likely to fail now. Would it be
> > possible/make sense to allow GFP_WAIT for allocations made from context
> > like systemtap_module_init() that may sleep because they are made from
> > user context?
>
> I agree, those contexts which can sleep, should. Not only does this
> make it more likely we'll get the memory we want, but also makes us
> better citizens with the rest of the kernel.
>
> Josh
>
I haven't seen this explicitly mentioned wrt this thread or PR13146, but
uprobes and uretprobe handlers (which are called from the utrace
report_signal callback) can sleep.
Jim
next prev parent reply other threads:[~2011-09-27 23:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110901143940.13672.qmail@sourceware.org>
2011-09-27 14:52 ` Mark Wielaard
2011-09-27 22:03 ` Josh Stone
2011-09-27 23:01 ` Jim Keniston [this message]
2011-09-28 12:12 ` Mark Wielaard
2011-10-05 13:44 ` David Smith
2011-10-05 13:47 ` David Smith
2011-10-05 15:24 ` Jim Keniston
2011-10-05 16:00 ` Ananth N Mavinakayanahalli
2011-10-25 12:07 ` Fixed PR13146 by not allowing memory allocations to sleep Frank Ch. Eigler
2011-10-25 12:19 ` Mark Wielaard
2011-10-31 10:26 ` Mark Wielaard
2011-10-31 15:19 ` Frank Ch. Eigler
2011-10-31 15:30 ` Mark Wielaard
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