Messages in this thread | | | Subject | Re: [RFC 4/9] Atomic reclaim: Save irq flags in vmscan.c | From | Andi Kleen <> | Date | 14 Aug 2007 22:02:23 +0200 |
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Christoph Lameter <clameter@sgi.com> writes:
> Reclaim can be called with interrupts disabled in atomic reclaim. > vmscan.c is currently using spinlock_irq(). Switch to spin_lock_irqsave().
I like the idea in principle. If this fully works out we could potentially keep less memory free by default which would be a good thing in general: free memory is bad memory.
But would be interesting to measure what the lock changes do to interrupt latency. Probably nothing good.
A more benign alternative might be to just set a per CPU flag during these critical sections and then only do atomic reclaim on a local interrupt when the flag is not set. That would make it a little less reliable, but much less intrusive and with some luck still give many of the benefits.
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