Messages in this thread | | | From | Andi Kleen <> | Subject | Re: Some interesting observations when trying to optimize vmstat handling | Date | Fri, 9 Nov 2007 00:07:42 +0100 |
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> There is an interrupt enable overhead of 48 cycles that would be good to > be able to eliminate (Kernel code usually moves counter increments into > a neighboring interrupt disable section so that __ function can be used).
Replace the push flags ; popf with test $IFMASK,flags ; jz 1f; sti ; 1: That will likely make it much faster (but also bigger)
The only problem is that there might be some code who relies on restore_flags() restoring other flags that IF, but at least for interrupts and local_irq_save/restore it should be fine to change.
-Andi
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