From: Kay Sievers Date: Mon, 9 Mar 2009 13:18:52 +0000 (+0100) Subject: vcs: hook sysfs devices into object lifetime instead of "binding" X-Git-Tag: v2.6.30-rc1~671^2~10 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4995f8ef9d3aac72745e12419d7fbaa8d01b1d81;p=pandora-kernel.git vcs: hook sysfs devices into object lifetime instead of "binding" During bootup performance tracing I noticed many occurrences of vca* device creation and removal, leading to the usual userspace uevent processing, which are, in this case, rather pointless. A simple test showing the kernel timing (not including all the work userspace has to do), gives us these numbers: $ time for i in `seq 1000`; do echo a > /dev/tty2; done real 0m1.142s user 0m0.015s sys 0m0.540s If we move the hook for the vcs* driver core devices from the tty "binding" to the vc allocation/deallocation, which is what the vcs* devices represent, we get the following numbers: $ time for i in `seq 1000`; do echo a > /dev/tty2; done real 0m0.152s user 0m0.030s sys 0m0.072s Cc: Alan Cox Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed