Messages in this thread | | | From | Mel Gorman <> | Subject | [PATCH 0/3] Reduce length of the eagerfpu path during x86 context switches | Date | Wed, 6 Aug 2014 13:55:22 +0100 |
| |
Eager FPU switching is used on CPUs that support xsave on the grounds that CPUs that support it can optimise the switch with xsaveopt and xrstor instead of serialising by updating cr0.TS which has serialising semantics.
The path for eagerfpu is fatter than it needs to be because it still maintains the fpu_counter for lazy FPU switches even though the information is never used. This patch splits the paths optimises the eagerfpu path a little. The benefit is marginal, it was just noticed when looking at why integer-only workloads were spending time saving/restoring FPU states.
arch/x86/include/asm/fpu-internal.h | 46 +++++++++++++++++++++++++++++-------- arch/x86/kernel/process_32.c | 2 +- arch/x86/kernel/process_64.c | 2 +- 3 files changed, 38 insertions(+), 12 deletions(-)
-- 1.8.4.5
| |