cvs commit: src/sys/vm vm_contig.c vm_page.c vm_pageq.c
alc at cs.rice.edu
Wed Feb 7 05:46:32 UTC 2007
Robert Watson wrote:
> On Mon, 5 Feb 2007, Alan Cox wrote:
>> alc 2007-02-05 06:02:55 UTC
>> FreeBSD src repository
>> Modified files:
>> sys/vm vm_contig.c vm_page.c vm_pageq.c
>> Change the free page queue lock from a spin mutex to a default
>> mutex. With the demise of Alpha support, there is no longer a
>> reason for
>> it to be a spin mutex.
> Is there any measurable performance change from this? In the past,
> I've observed significantly higher cost for acquiring spin mutexes vs.
> sleep mutexes in micro-benchmarking. The change was most striking on
> Intel Xeon P4 hardware with an SMP kernel, and quite a bit less so on
> other platforms.
I didn't notice any difference for buildworld on a 4-way Opteron.
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