Re: Disabling interrupts before block device request call

[Jens Axboe <axboe@suse.de>]

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