From: Anton Blanchard Date: Mon, 4 Jun 2012 16:02:22 +0000 (+0000) Subject: powerpc: Optimise the 64bit optimised __clear_user X-Git-Tag: v3.6-rc1~132^2~51 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf8fb5533f35709ba7e31560264b565a9c7a090f;p=pandora-kernel.git powerpc: Optimise the 64bit optimised __clear_user I blame Mikey for this. He elevated my slightly dubious testcase: to benchmark status. And naturally we need to be number 1 at creating zeros. So lets improve __clear_user some more. As Paul suggests we can use dcbz for large lengths. This patch gets the destination cacheline aligned then uses dcbz on whole cachelines. Before: 10485760000 bytes (10 GB) copied, 0.414744 s, 25.3 GB/s After: 10485760000 bytes (10 GB) copied, 0.268597 s, 39.0 GB/s 39 GB/s, a new record. Signed-off-by: Anton Blanchard Tested-by: Olof Johansson Acked-by: Olof Johansson Signed-off-by: Benjamin Herrenschmidt --- Reading git-diff-tree failed