Re: Disabling interrupts before block device request call
Jens Axboe (axboe@suse.de)
Sat, 26 May 2001 00:01:19 +0200
On Fri, May 25 2001, Alexandr Andreev wrote:
> Hi, list
> In ll_rw_block.c, before calling block device specific request function
> ( i mean do_hd_request, do_ftl_request, ... ) the io_request_lock is
> locking, and all interrupts are disabling. I know, that request handler
> routine have to be atomic, but when we read data from a flash device (
> for example ) we use a timeouts. Where do we have to enable timer
> interrupts, or should we disable all interrupts?
Even with dropping io_request_lock, it's not recommended to sleep inside
the request_fn. WIth plugging, you are basically preventing the other
plugged queues from being run until you return.
You could use a timer or similar to call you on a specified timeout
instead.
--
Jens Axboe
-
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/