Re: [PATCH] delay accounting taskstats interface: send tgid once locking fix

Hi,

On 27/06/06, Shailabh Nagar <[email protected]> wrote:

Use irqsave variants of spin_lock for newly introduced tsk->signal->stats_lock
The lock is nested within tasklist_lock as part of release_task() and hence
there is possibility of a AB-BA deadlock if a timer interrupt occurs while
stats_lock is held.

Thanks to Arjan van de Ven for pointing out the lock bug.
The patch conservatively converts all use of stats_lock to irqsave variant
rather than only the call within taskstats_tgid_free which is the function
called within tasklist_lock protection.

Signed-off-by: Shailabh Nagar <[email protected]>

Problem solved, thanks.

Regards,
Michal

--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/wiki/)
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---

• References:
  • Re: + delay-accounting-taskstats-interface-send-tgid-once.patch added to -mm tree
    • From: Arjan van de Ven <[email protected]>
  • Re: + delay-accounting-taskstats-interface-send-tgid-once.patch added to -mm tree
    • From: Shailabh Nagar <[email protected]>
  • Re: + delay-accounting-taskstats-interface-send-tgid-once.patch added to -mm tree
    • From: Shailabh Nagar <[email protected]>
  • [PATCH] delay accounting taskstats interface: send tgid once locking fix
    • From: Shailabh Nagar <[email protected]>

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