lkml.org 
[lkml]   [2011]   [Jan]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: percpu related boot crash on x86
Hello,

On Thu, Jan 20, 2011 at 12:12:47PM +0100, Eric Dumazet wrote:
> Le jeudi 20 janvier 2011 à 11:47 +0100, Peter Zijlstra a écrit :
> > On Thu, 2011-01-20 at 10:31 +0200, Pekka Enberg wrote:
> > > if (!irqs_disabled())
> > >
> > > guard around the debugging code to make vfree() always work with IRQs
> > > disabled.
> >
> > That won't be sufficient, __purge_vmap_area_lazy() needs to call
> > flush_tlb_kernel_range() occasionally.
> >
> > There really is a good reason vmalloc()/vfree() don't work with
> > interrupts disabled.
>
> Hmm, I would try to increase PERCPU_DYNAMIC_RESERVE, or pcpu_mem_alloc()
> could try to use kzalloc() even for allocations bigger than one PAGE,
> and fallback to vzalloc().

It already handles all those stuff. As I wrote in the other message,
I don't think this problem has much to do with percpu allocator
itself.

> We have more alloc_percpu() uses, we also should try to use first chunk
> if possible.

Yeah, but that's true. It's probably too small at this point. Maybe
there should be a way to monitor percpu memory status, a proc entry or
something so that we can have more data on sizing.

Thanks.

--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-01-20 12:21    [W:0.067 / U:16.220 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site