Messages in this thread | | | Date | Wed, 17 May 2006 13:25:00 +1000 | From | Nick Piggin <> | Subject | Re: [patch 00/14] remap_file_pages protection support |
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Andreas Mohr wrote:
>Hi, > >On Tue, May 16, 2006 at 09:31:12AM -0700, Valerie Henson wrote: > >>On Tue, May 16, 2006 at 03:51:35PM +0200, Andreas Mohr wrote: >> >>>I cannot offer much other than some random confirmation that from my own >>>oprofiling, whatever I did (often running a load test script consisting of >>>launching 30 big apps at the same time), find_vma basically always showed up >>>very prominently in the list of vmlinux-based code (always ranking within the >>>top 4 or 5 kernel hotspots, such as timer interrupts, ACPI idle I/O etc.pp.). >>>call-tracing showed it originating from mmap syscalls etc., and AFAIR quite >>>some find_vma activity from oprofile itself. >>> >>This is important: Which kernel? >> > >I had some traces still showing find_vma prominently during a profiling run >just yesterday, with a very fresh 2.6.17-rc4-ck1 (IOW, basically 2.6.17-rc4). >I added some cache prefetching in the list traversal a while ago, and IIRC >that improved profiling times there, but cache prefetching is very often >a bandaid in search for a real solution: a better data-handling algorithm. >
If you want to try out the patch and see what it does for you, that would be interesting. I'll repost a slightly cleaned up version in a couple of hours.
Nick --
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