lkml.org 
[lkml]   [1999]   [May]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: hinting system for poll (was Re: /dev/poll vs. aio_)
In message <199905212222.PAA03854@pizda.davem.net>, "David S. Miller" writes:
>Run 2.2.9, this tcp_tw_deschedule bogosity will go away.
I just ported the hinting system over to 2.2.9 and things look nicer
now.

I just did a very quick benchmark. The outputs of readprofile are
probably biased in favor of the unmodified system because lacking file
descriptors it skipped about 600,000 requests (see the difference in
generic_copy_from_user).

httperf on local system 1,000,000 requests with rate 1200 r/s:

no hinting: min 0.0 avg 419.1 max 1104.6 stddev 168.2 (177 samples)
hinting: min 829.8 avg 1197.3 max 1252.2 stddev 37.4 (167 samples)

And the readprofile output is:

non-hinting:
18132 sock_poll 453.3000
13874 inet_poll 315.3182
3933 synchronize_irq 196.6500
15200 tcp_poll 63.3333
18830 do_select 32.6910
1162 sock_close 19.3667
1279 tcp_write_space 15.2262
1146 synchronize_bh 15.0789
894 __generic_copy_from_user 14.9000
496 system_call 8.8571

hinting:
6080 synchronize_irq 304.0000
2090 __generic_copy_from_user 34.8333
34394 do_select 30.5996
1577 system_call 28.1607
1981 synchronize_bh 26.0658
140 ret_with_reschedule 8.7500
973 do_gettimeofday 8.1083
816 __wake_up 7.8462
183 signal_return 7.6250
241 sock_wfree 7.5312
[...]
126 inet_poll 2.2500
105 sock_poll 2.1875
417 tcp_poll 1.0322

Well, nontheless, I hope you find this interesting.

Greetings,
Niels.

--
Niels Provos <provos@citi.umich.edu> finger provos@umich.edu for pgp info

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:51    [W:0.296 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site