diff options
| author | Tejun Heo <tj@kernel.org> | 2010-07-02 10:03:52 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-07-02 10:59:24 +0200 |
| commit | ad72cf9885c536e3adae03f8337557ac9dd1e4bb (patch) | |
| tree | e93af7f241987ffe365792c0130d182b0ac890d1 /include/linux/libata.h | |
| parent | d313dd85ad846bc768d58e9ceb28588f917f4c9a (diff) | |
libata: take advantage of cmwq and remove concurrency limitations
libata has two concurrency related limitations.
a. ata_wq which is used for polling PIO has single thread per CPU. If
there are multiple devices doing polling PIO on the same CPU, they
can't be executed simultaneously.
b. ata_aux_wq which is used for SCSI probing has single thread. In
cases where SCSI probing is stalled for extended period of time
which is possible for ATAPI devices, this will stall all probing.
#a is solved by increasing maximum concurrency of ata_wq. Please note
that polling PIO might be used under allocation path and thus needs to
be served by a separate wq with a rescuer.
#b is solved by using the default wq instead and achieving exclusion
via per-port mutex.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Diffstat (limited to 'include/linux/libata.h')
| -rw-r--r-- | include/linux/libata.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/libata.h b/include/linux/libata.h index b85f3ff34d7..f010f18a0f8 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -751,6 +751,7 @@ struct ata_port { struct ata_host *host; struct device *dev; + struct mutex scsi_scan_mutex; struct delayed_work hotplug_task; struct work_struct scsi_rescan_task; |