> We could check ctx->reqs_active before scheduling to determine whether
> or not we are waiting for I/O, but this would require taking the
> context lock in order to be accurate. Given that the test would be
> only for the sake of book keeping, it might be okay to do it outside
> of the lock.
>
> Zach, what are your thoughts on this?
I agree that it'd be OK to test it outside the lock, though we'll want
some commentary:
/* Try to only show up in io wait if there are ops in flight */
if (ctx->reqs_active)
io_schedule();
else
schedule();
It's cheap, safe, and accurate the overwhelming majority of the time :).
We only need it in read_events(). The other two io_schedule() calls are
only reached to wait on pending reqs specifically.
It still won't make sense for iocbs which aren't performing IO, but I
guess that's one more bridge to cross when we come to it.
Do you want to throw this tiny patch together and submit it?
- z
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
