Re: io_request_lock and system performance (can it be replaced?)

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Thu Mar 23 2000 - 09:15:23 EST


> This may not be the best example, but the point is that reqeusts
> to different devices on different CPUs will cause lots of spin
> lock contention. Is this what would happen or am I completely
> missunderstanding the implementation? Would it be better for
> performance to have a request_lock associated with each device's
> request_queue_t so blocking only occurs when the same queue might
> be touched by two CPUs? Please enlighten me if I've totally missed
> the mark on this.

In part the lock should only be held very briefly so it shouldnt be that
contented. As a whole you are right. Historically we had one request
queue for the system. The locking reflects that state of affairs. It would
not be wise to change it for 2.4

-
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/



This archive was generated by hypermail 2b29 : Thu Mar 23 2000 - 21:00:38 EST