driver core: check bus->match without holding device lock
This patch moves bus->match out from driver_probe_device and
does not hold device lock to check the match between a device
and a driver.
The idea has been verified by the commit 6cd495860901,
which leads to a faster boot. But the commit 6cd495860901 has
the following drawbacks: 1),only does the quick check in
the path of __driver_attach->driver_probe_device, not in other
paths; 2),for a matched device and driver, check the same match
twice. It is a waste of cpu ,especially for some drivers with long
device id table (eg. usb-storage driver).
This patch adds a helper of driver_match_device to check the match
in all paths, and testes the match only once.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 83f32b8..8547b78 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -198,7 +198,7 @@
int err = -ENODEV;
dev = bus_find_device_by_name(bus, NULL, buf);
- if (dev && dev->driver == NULL) {
+ if (dev && dev->driver == NULL && driver_match_device(drv, dev)) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
down(&dev->sem);