From: Daniel Vetter Date: Sun, 25 Mar 2012 17:47:34 +0000 (+0200) Subject: drm/i915: don't call shmem_read_mapping unnecessarily X-Git-Tag: v3.5-rc1~83^2~140^2~63 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=692a576b9ddf8006f1559e14a5022c0a100440f1;p=pandora-kernel.git drm/i915: don't call shmem_read_mapping unnecessarily This speeds up pwrite and pread from ~120 µs ro ~100 µs for reading/writing 1mb on my snb (if the backing storage pages are already pinned, of course). v2: Chris Wilson pointed out a glaring page reference bug - I've unconditionally dropped the reference. With that fixed (and the associated reduction of dirt in dmesg) it's now even a notch faster. v3: Unconditionaly grab a page reference when dropping dev->struct_mutex to simplify the code-flow. Tested-by: Chris Wilson Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed