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* Block layer still stack abuser?
@ 2007-02-16 11:57 Pierre Ossman
  2007-02-22  2:48 ` Neil Brown
  0 siblings, 1 reply; 5+ messages in thread
From: Pierre Ossman @ 2007-02-16 11:57 UTC (permalink / raw)
  To: LKML

I was wondering if the block layer has been changed into a more serialized
manner yet? I've been trying to google this, but so far no luck. I know there
was some talk about removing the stack based approach, but I can't find any
information about where this went.

If it is currently fixed, a pointer to from which version would be nice.

Rgds
-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  PulseAudio, core developer          http://pulseaudio.org
  rdesktop, core developer          http://www.rdesktop.org

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Block layer still stack abuser?
  2007-02-16 11:57 Block layer still stack abuser? Pierre Ossman
@ 2007-02-22  2:48 ` Neil Brown
  2007-02-22  3:44   ` Christoph Hellwig
  2007-02-22  5:44   ` Pierre Ossman
  0 siblings, 2 replies; 5+ messages in thread
From: Neil Brown @ 2007-02-22  2:48 UTC (permalink / raw)
  To: Pierre Ossman; +Cc: LKML

On Friday February 16, drzeus-list@drzeus.cx wrote:
> I was wondering if the block layer has been changed into a more serialized
> manner yet? I've been trying to google this, but so far no luck. I know there
> was some talk about removing the stack based approach, but I can't find any
> information about where this went.
> 
> If it is currently fixed, a pointer to from which version would be nice.

Might this:
   http://lkml.org/lkml/2007/2/10/22

relate to your question?
If you are talking about stacking block device (via dm or md), then a
patch to fix this in in -mm but there are or were some potential
issues in dm that seem to be holding it up.

NeilBrown

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Block layer still stack abuser?
  2007-02-22  2:48 ` Neil Brown
@ 2007-02-22  3:44   ` Christoph Hellwig
  2007-02-22  3:46     ` Neil Brown
  2007-02-22  5:44   ` Pierre Ossman
  1 sibling, 1 reply; 5+ messages in thread
From: Christoph Hellwig @ 2007-02-22  3:44 UTC (permalink / raw)
  To: Neil Brown; +Cc: Pierre Ossman, LKML, schwidefsky

On Thu, Feb 22, 2007 at 01:48:00PM +1100, Neil Brown wrote:
> Might this:
>    http://lkml.org/lkml/2007/2/10/22
> 
> relate to your question?
> If you are talking about stacking block device (via dm or md), then a
> patch to fix this in in -mm but there are or were some potential
> issues in dm that seem to be holding it up.

What are the current blocking issues?  There are a lot of users of dm/md
double-stacking (e.g. mirroring + multipath) that are in deep trouble
currently and could be helped greatly with this patch.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Block layer still stack abuser?
  2007-02-22  3:44   ` Christoph Hellwig
@ 2007-02-22  3:46     ` Neil Brown
  0 siblings, 0 replies; 5+ messages in thread
From: Neil Brown @ 2007-02-22  3:46 UTC (permalink / raw)
  To: Christoph Hellwig; +Cc: Pierre Ossman, LKML, schwidefsky

On Thursday February 22, hch@infradead.org wrote:
> On Thu, Feb 22, 2007 at 01:48:00PM +1100, Neil Brown wrote:
> > Might this:
> >    http://lkml.org/lkml/2007/2/10/22
> > 
> > relate to your question?
> > If you are talking about stacking block device (via dm or md), then a
> > patch to fix this in in -mm but there are or were some potential
> > issues in dm that seem to be holding it up.
> 
> What are the current blocking issues?  There are a lot of users of dm/md
> double-stacking (e.g. mirroring + multipath) that are in deep trouble
> currently and could be helped greatly with this patch.

All I know is what is in that mail message that I linked to.

NeilBrown

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Block layer still stack abuser?
  2007-02-22  2:48 ` Neil Brown
  2007-02-22  3:44   ` Christoph Hellwig
@ 2007-02-22  5:44   ` Pierre Ossman
  1 sibling, 0 replies; 5+ messages in thread
From: Pierre Ossman @ 2007-02-22  5:44 UTC (permalink / raw)
  To: Neil Brown; +Cc: LKML

Neil Brown wrote:
> On Friday February 16, drzeus-list@drzeus.cx wrote:
>   
>> I was wondering if the block layer has been changed into a more serialized
>> manner yet? I've been trying to google this, but so far no luck. I know there
>> was some talk about removing the stack based approach, but I can't find any
>> information about where this went.
>>
>> If it is currently fixed, a pointer to from which version would be nice.
>>     
>
> Might this:
>    http://lkml.org/lkml/2007/2/10/22
>
> relate to your question?
> If you are talking about stacking block device (via dm or md), then a
> patch to fix this in in -mm but there are or were some potential
> issues in dm that seem to be holding it up.
>
>   

Yes, I am. I know there has been general work to reduce stack usage here
and there, but the final suggested solution was to serialize all the
block subsystems so that only one was present on the stack at any given
time.

I was constantly hitting this problem a few years ago when I was running
md+xfs+nfs. The fix was in -mm back then as well. ;)

Rgds

-- 
     -- Pierre Ossman

  Linux kernel, MMC maintainer        http://www.kernel.org
  PulseAudio, core developer          http://pulseaudio.org
  rdesktop, core developer          http://www.rdesktop.org


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2007-02-22  5:44 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-02-16 11:57 Block layer still stack abuser? Pierre Ossman
2007-02-22  2:48 ` Neil Brown
2007-02-22  3:44   ` Christoph Hellwig
2007-02-22  3:46     ` Neil Brown
2007-02-22  5:44   ` Pierre Ossman

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