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Chris Wilson authored
Whilst inspecting the asm for clflush_cache_range() and some perf profiles that required extensive flushing of single cachelines (from part of the intel-gpu-tools GPU benchmarks), we noticed that gcc was reloading boot_cpu_data.x86_clflush_size on every iteration of the loop. We can manually hoist that read which perf regarded as taking ~25% of the function time for a single cacheline flush. Signed-off-by:
Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by:
"H. Peter Anvin" <hpa@zytor.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Borislav Petkov <bp@suse.de> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com> Link: http://lkml.kernel.org/r/1452246933-10890-1-git-send-email-chris@chris-wilson.co.ukSigned-off-by:
Thomas Gleixner <tglx@linutronix.de>
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