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 6cd4958609,
which leads to a faster boot. But the commit 6cd4958609 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>
This commit is contained in:
Ming Lei
2009-01-21 23:27:47 +08:00
committed by Greg Kroah-Hartman
parent 4a67a1bc0b
commit 49b420a13f
3 changed files with 13 additions and 13 deletions

View File

@@ -86,6 +86,11 @@ extern void bus_remove_driver(struct device_driver *drv);
extern void driver_detach(struct device_driver *drv);
extern int driver_probe_device(struct device_driver *drv, struct device *dev);
static inline int driver_match_device(struct device_driver *drv,
struct device *dev)
{
return drv->bus->match && drv->bus->match(dev, drv);
}
extern void sysdev_shutdown(void);