Re: Some interesting observations when trying to optimize vmstat handling

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To: Christoph Lameter <clameter@...>
Cc: <linux-kernel@...>, <linux-mm@...>, Mathieu Desnoyers <mathieu.desnoyers@...>
Date: Thursday, November 8, 2007 - 7:07 pm

> There is an interrupt enable overhead of 48 cycles that would be good to

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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Messages in current thread:
Re: Some interesting observations when trying to optimize vm..., Andi Kleen, (Thu Nov 8, 7:07 pm)
Re: Some interesting observations when trying to optimize vm..., Jeremy Fitzhardinge, (Thu Nov 8, 8:19 pm)