driver core: check bus->match without holding device lock
commit49b420a13ff95b449947181190b08367348e3e1b
authorMing Lei <tom.leiming@gmail.com>
Wed, 21 Jan 2009 15:27:47 +0000 (21 23:27 +0800)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 24 Mar 2009 23:38:24 +0000 (24 16:38 -0700)
tree5feec1d1eac071e46c9aacec4255d891fa4f7ed2
parent4a67a1bc0b3a0db017b560cee27370d141c58e25
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>
drivers/base/base.h
drivers/base/bus.c
drivers/base/dd.c