Commit 4995f8ef authored by Committed by Greg Kroah-HartmanBrowse files
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 <email@example.com> Signed-off-by: Kay Sievers <firstname.lastname@example.org> Signed-off-by: Greg Kroah-Hartman <email@example.com>
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