Messages in this thread | | | Subject | Re: Serious Kernel slowdown with HIMEM (4Gig) in 2.6.7 | Date | Mon, 16 Aug 2004 09:23:40 -0400 | From | "Lawrence E. Freil" <> |
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Iteresting idea, here is the /proc/mtrr output:
reg00: base=0x00000000 ( 0MB), size= 512MB: write-back, count=1 reg01: base=0x20000000 ( 512MB), size= 256MB: write-back, count=1 reg02: base=0x30000000 ( 768MB), size= 128MB: write-back, count=1 reg03: base=0x38000000 ( 896MB), size= 64MB: write-back, count=1 reg04: base=0x3c000000 ( 960MB), size= 32MB: write-back, count=1 reg05: base=0x3e000000 ( 992MB), size= 16MB: write-back, count=1 reg06: base=0xf0000000 (3840MB), size= 2MB: write-combining, count=1
The memory in question is the block from 896 to 1Gig. Looks pretty normal.
At this point I need to recompile "ls" with full profiling and time it with and without extended memory. I have a suspicion that it is related to "mmap" on data in a high memory buffer. It does not effect actual file read/write. Performance on that is pretty much the same.
>On Sat, Aug 14, 2004 at 12:43:11PM -0400, Lawrence E. Freil wrote: >> Though there is a consistant sys component that is slightly higher. I ran >> profiles three times for "fast" and three times for "slow". Here they are > >Try cat /proc/mtrr. I bet your system isn't marking some of its RAM >cachable in the MTRRs. > > -ben
-- Lawrence Freil Email:lef@freil.com 1768 Old Country Place Phone:(770) 667-9274 Woodstock, GA 30188
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