Messages in this thread | | | From | Denis Vlasenko <> | Subject | Re: [RESEND] tuning linux for high network performance? | Date | Thu, 24 Oct 2002 14:22:25 -0200 |
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On 23 October 2002 11:36, Roy Sigurd Karlsbakk wrote: > > > 905182 total 0.4741 > > > 121426 csum_partial_copy_generic 474.3203 > > > > Well, maybe take a look at this func and try to optimize it? > > I don't know assembly that good - sorry.
Well, I like it. Maybe I can look into it. Feel free to bug me :-)
> > > 93633 default_idle 1800.6346 > > > 74665 do_wp_page 111.1086 > > > > What's this? > > do_wp_page is Defined as a function in: mm/memory.c > > comments from the file: > [snip]
Please delete memory.o, rerun make bzImage, capture gcc command used for compiling memory.c, modify it:
gcc ... -o memory.o -> gcc ... -S -o memory.s ...
and examine assembler code. Maybe something will stick out (or use objdump to disassemble memory.o, I recall nice option to produce assembler output with C code intermixed as comments!) (send disasmed listing to me offlist).
> > > 65857 ide_intr 184.9916 > > > > You have 1 ide_intr per 2 csum_partial_copy_generic... hmmm... > > how large is your readahead? I assume you'd like to fetch > > more sectors from ide per interrupt. (I hope you do DMA ;) > > doing DMA - RAID-0 with 1MB chunk size on 4 disks.
You should aim at maxing out IDE performance. Please find out how many sectors you read in one go. Maybe:
# cat /proc/interrupts # dd bs=1m count=1 if=/dev/hda of=/dev/null # cat /proc/interrupts
and calculate how many IDE interrupts happened. (1mb = 2048 sectors) -- vda - 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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