On Mon, 18 Mar 2002, Martin J. Bligh wrote:
> OK, I finally got the -aa kernel series running in conjunction with the
> NUMA-Q discontigmem stuff. For some reason which I haven't debugged
> yet 2.4.19-pre3-aa2 won't boot on the NUMA-Q even without the discontigmem
> stuff in ... so I went back to 2.4.19-pre1-aa1, which I knew worked from
> last time around (thanks again for that patch).
>
> So just comparing aa+discontigmem to standard 2.4.18+discontigmem, I see
> kernel compile times are about 35s vs 26.5s ....
That's probably Andrea's pte-highmem code, which uses the
global kmap pool instead of doing cpu-local atomic kmaps.
He's been told about this becoming a scalability problem
but didn't believe it since I didn't have any numbers for
him. Maybe he believes it now since you've measured it ;)
> standard:
>
> 23991 total 0.0257
> 7679 default_idle 147.6731
> 3044 _text_lock_dcache 8.7221
> 2340 _text_lock_swap 43.3333
> 1160 do_anonymous_page 3.4940
> ...
> 109 kmap_high 0.3028
> 46 _text_lock_highmem 0.4071
>
> andrea:
> 38549 total 0.0405
> 13102 _text_lock_highmem 108.2810
> 8627 default_idle 165.9038
> 2578 kunmap_high 14.3222
> 2556 kmap_high 6.0857
> 1242 do_anonymous_page 3.2684
> 1052 _text_lock_swap 22.8696
> Andrea - is this your new highmem pte stuff doing this?
> Or is that not even in your tree as yet? Would be a shame if that's
> the problem as I really want to get the highmem pte stuff - allows
> me to put processes pagetables on their own nodes ....
You really want the pte-highmem by Arjan and Ingo, which uses
kmap_atomic (which is CPU-local and doesn't suffer the same
scalability problem as the global kmap pool).
regards,
Rik
-- <insert bitkeeper endorsement here>http://www.surriel.com/ http://distro.conectiva.com/
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This archive was generated by hypermail 2b29 : Sat Mar 23 2002 - 22:00:17 EST