Messages in this thread | | | Date | Tue, 26 Oct 2004 16:15:00 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] faster signal handling on x86 |
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On Tue, 26 Oct 2004, Zachary Amsden wrote: > > I noticed an unneeded write to dr7 in the signal handling path for x86. > We only need to write to dr7 if there is a breakpoint to re-enable, and > MOVDR is a serializing instruction, which is expensive. Getting rid of > it gets a 33% faster signal delivery path (at least on Xeon - I didn't > test other CPUs, so your gain may vary).
I'm suprised it is _that_ slow, but sure, no problem, the patch just makes it match all the other paths.
I suspect Xeon is alone in being _that_ slow - I bet Netburst flushes the whole trace cache on db7 writes.
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