| Message ID | 1458660792-3035-2-git-send-email-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 03/22/2016 09:33 AM, Kevin Wolf wrote: > We had to disable I/O throttling with synchronous requests because we > didn't use to run timers in nested event loops when the code was > introduced. This isn't true any more, and throttling works just fine > even when using the synchronous API. > > The removed code is in fact dead code since commit a8823a3b ('block: Use > blk_co_pwritev() for blk_write()') because I/O throttling can only be > set on the top layer, but BlockBackend always uses the coroutine > interface now instead of using the sync API emulation in block.c. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > block/io.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/block/io.c b/block/io.c > index cce508a..e4438da 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -561,17 +561,6 @@ static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, > .flags = flags, > }; > > - /** > - * In sync call context, when the vcpu is blocked, this throttling timer > - * will not fire; so the I/O throttling function has to be disabled here > - * if it has been enabled. > - */ > - if (bs->io_limits_enabled) { > - fprintf(stderr, "Disabling I/O throttling on '%s' due " > - "to synchronous I/O.\n", bdrv_get_device_name(bs)); And we get rid of an fprintf(). Nice bonus. Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/block/io.c b/block/io.c index cce508a..e4438da 100644 --- a/block/io.c +++ b/block/io.c @@ -561,17 +561,6 @@ static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, .flags = flags, }; - /** - * In sync call context, when the vcpu is blocked, this throttling timer - * will not fire; so the I/O throttling function has to be disabled here - * if it has been enabled. - */ - if (bs->io_limits_enabled) { - fprintf(stderr, "Disabling I/O throttling on '%s' due " - "to synchronous I/O.\n", bdrv_get_device_name(bs)); - bdrv_io_limits_disable(bs); - } - if (qemu_in_coroutine()) { /* Fast-path if already in coroutine context */ bdrv_rw_co_entry(&rwco);
We had to disable I/O throttling with synchronous requests because we didn't use to run timers in nested event loops when the code was introduced. This isn't true any more, and throttling works just fine even when using the synchronous API. The removed code is in fact dead code since commit a8823a3b ('block: Use blk_co_pwritev() for blk_write()') because I/O throttling can only be set on the top layer, but BlockBackend always uses the coroutine interface now instead of using the sync API emulation in block.c. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block/io.c | 11 ----------- 1 file changed, 11 deletions(-)