Re: [PATCH] backing dev unplugging

Andrew Morton
2004-03-10T23:52:36Z

jbarnes@sgi.com (Jesse Barnes) wrote:
>
> -------------------------------------
> w/Jens' patch: ~47149 I/Os per second

Happier.

> [root@revenue sio]# readprofile -m /root/System.map | sort -nr +2 | head -20
> 181993 default_idle 5687.2812
> 624772 snidle 1627.0104
> 209129 cpu_idle 435.6854
> 4755 dio_bio_end_io 12.3828
> 6593 scsi_end_request 12.1195
> 435 ia64_spinlock_contention 6.7969
> 2959 sn_dma_flush 4.4033

Do you know where that spinlock contention is coming from?

(We have a little patch for x86 which places the spinning code inline in the
caller of spin_lock() so it appears nicely in profiles.)