Messages in this thread | | | Date | Wed, 24 Jul 2002 14:49:18 +0200 (MET DST) | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: please DON'T run 2.5.27 with IDE! |
| |
On Wed, 24 Jul 2002, Jens Axboe wrote:
> On Wed, Jul 24 2002, Bartlomiej Zolnierkiewicz wrote: > > > void blk_start_queue(request_queue_t *q) > > > { > > > if (test_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)) { > > > unsigned long flags; > > > > > > ================== possigle race here for qeue_flags BTW. > > > > > > spin_lock_irqsave(q->queue_lock, flags); > > > clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags); > > > > > > if (!elv_queue_empty(q)) > > > q->request_fn(q); > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > If we call it from within request_fn then if this isn't recursion on the > > > kernel stack then I don't know... > > > > You really don't know. > > > > And funny thing is I have diffirent blk_start_queue() function in my tree > > (2.5.27) ? Without described above race and without possibilty of > > recursion... > > > > 2.5.27:drivers/block/ll_rw_blk.c > > void blk_start_queue(request_queue_t *q) > > { > > if (test_and_clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags)) { > > unsigned long flags; > > > > spin_lock_irqsave(q->queue_lock, flags); > > if (!elv_queue_empty(q)) > > q->request_fn(q); > > spin_unlock_irqrestore(q->queue_lock, flags); > > } > > } > > Yep, the version Martin posted must be really old.
It's worst. Martin's version exists only in his tree (mind?). I checked back revision and blk_start_queue() was inroduced in 2.5.19 and it was the correct one.
> -- > 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/
| |