Messages in this thread | | | Date | Wed, 9 Mar 2005 03:28:32 -0800 | From | Andrew Morton <> | Subject | Re: aio stress panic on 2.6.11-mm1 |
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Arjan van de Ven <arjan@infradead.org> wrote: > > On Wed, 2005-03-09 at 16:34 +0530, Suparna Bhattacharya wrote: > > Any sense of how costly it is to use spin_lock_irq's vs spin_lock > > (across different architectures) > > on x86 it makes a difference of maybe a few cycles. At most. > However please consider using spin_lock_irqsave(); the _irq() variant, > while it can be used correctly, is a major source of bugs since it > unconditionally enables interrupts on unlock. >
spin_lock_irq() is OK for down_*(), since down() can call schedule() anyway.
spin_lock_irqsave() should be used in up_*() and I guess down_*_trylock(), although the latter shouldn't need to go into the slowpath anyway.
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