From: Arjan van de Ven Date: Sun, 14 Sep 2008 15:32:06 +0000 (-0700) Subject: device model: Do a quickcheck for driver binding before doing an expensive check X-Git-Tag: v2.6.28-rc1~284^2~17 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6cd49586090187a2a145bb6570fb2392f121aa22;p=pandora-kernel.git device model: Do a quickcheck for driver binding before doing an expensive check This patch adds a quick check for the driver<->device match before taking the locks and doin gthe expensive checks. Taking the lock hurts in asynchronous boot context where the device lock gets hit; one of the init functions takes the lock and goes to do an expensive hardware init; the other init functions walk the same PCI list and get stuck on the lock as a result. For the common case, we can know there's no chance whatsoever of a match if the device isn't in the drivers ID table... so this patch does that check as a best-effort-avoid-the-lock approach. Bootcharts for before and after can be seen at http://www.fenrus.org/before.svg http://www.fenrus.org/after.svg Note the long time "agp_ali_init" takes in the first graph; my laptop doesn't even have an ALI chip in it! (the bootgraphs look a bit dissimilar, but that's the point, the first one has a bunch of arbitrary delays in it that cause it to look very different) This reduces my kernel boot time by about 20% Signed-off-by: Arjan van de Ven Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed