Messages in this thread | | | From | "Oberman, Laurence (HAS GSE)" <> | Date | Fri, 14 Oct 2011 14:48:15 +0100 | Subject | RE: Regression in reading /proc/stat in the newer kernels with large SMP and NUMA configurations |
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Hi Eric, I am preparing for that test. Need to stage a full RHEL6. I had only updated the kernel on an existing SLES10. Standby and I will run the tests for you.
Thanks Laurence
-----Original Message----- From: Eric Dumazet [mailto:eric.dumazet@gmail.com] Sent: Friday, October 14, 2011 9:47 AM To: Seger, Mark Cc: Oberman, Laurence (HAS GSE); linux-kernel@vger.kernel.org; Cabaniols, Sebastien Subject: RE: Regression in reading /proc/stat in the newer kernels with large SMP and NUMA configurations
Le vendredi 14 octobre 2011 à 14:36 +0100, Seger, Mark a écrit :
> For me the easiest reproducer, which admittedly doesn't show any > deeper analysis, is to just run "cat /proc/stat>/dev/null" in a loop > and time it.
OK, but you already provided a global number.
We would like to check where in kernel cpu time is consumed. Maybe something really obvious could pop out.
"perf" is provided in kernel sources, and really is a piece of cake.
cd tools/perf ; make
2x4x2 means : Two sockets, 4 cores per physical package, 2 threads per core.
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