Messages in this thread | | | Date | Mon, 6 Dec 2004 17:43:31 -0200 | From | Marcelo Tosatti <> | Subject | Re: HIGHMEM=4G slows down ps2pdf with 2.4.28 |
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On Mon, Dec 06, 2004 at 04:41:18PM -0200, Marcelo Tosatti wrote: > On Fri, Dec 03, 2004 at 09:58:19PM +0100, Alain Tesio wrote: > > On Thu, 2 Dec 2004 17:08:15 -0200 > > Marcelo Tosatti <marcelo.tosatti@cyclades.com> wrote: > > > > > On Wed, Dec 01, 2004 at 11:25:22PM +0100, Alain Tesio wrote: > > > > Hi, > > > > > > > > With a 2.4.28 kernel, 1.5 Go RAM and nothing exotic, everything works fine > > > > with CONFIG_HIGHMEM4G and CONFIG_HIGHMEM=y except that > > > > ps2pdf is about 30 times slower > > > > > How does /proc/mtrr look like? > > > > > > Maybe some of your memory is configured as uncacheable. > > > > reg00: base=0x00000000 ( 0MB), size=1024MB: write-back, count=1 > > reg01: base=0x40000000 (1024MB), size= 256MB: write-back, count=1 > > reg02: base=0x50000000 (1280MB), size= 128MB: write-back, count=1 > > reg03: base=0x58000000 (1408MB), size= 64MB: write-back, count=1 > > reg04: base=0x5c000000 (1472MB), size= 32MB: write-back, count=1 > > reg05: base=0x5e000000 (1504MB), size= 16MB: write-back, count=1 > > > > I don't think that the hosting company played with the bios settings, > > and I don't do anything special with memory. > > Alain, > > All memory is correctly configured in MTRR it seems (all of it is write-back cacheable). > > Do you have CONFIG_HIGHIO=y ? That might help a lot. The kernel has to use > bounce buffers for IO otherwise.
However you report 30x slower without HIGHMEM - thats a bit too much for the added overhead of bounce buffers. Anyway, try CONFIG_HIGHIO=y if you dont have it configured this way. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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