[PATCH 0/7] [RESEND][v4] x86: rework tlb range flushing code

From: Dave Hansen
Date: Tue Jul 01 2014 - 12:51:10 EST


x86 Maintainers,

Could this get picked up in to the x86 tree, please? That way,
it will get plenty of time to bake before the 3.17 merge window.

Changes from v3:
* Include the patch I was using to gather detailed statistics
about the length of the ranged TLB flushes
* Fix some documentation typos
* Add a patch to rework the remote tlb flush code to plumb the
tracepoints in easier, and add missing tracepoints
* use __print_symbolic() for the human-readable tracepoint
descriptions
* change an int to bool in patch 1
* Specifically call out that we removed itlb vs. dtlb logic

Changes from v2:
* Added a brief comment above the ceiling tunable
* Updated the documentation to mention large pages and say
"individual flush" instead of invlpg in most cases.

I guess the x86 tree is probably the right place to queue this
up.

I've run this through a variety of systems in the LKP harness,
as well as running it on my desktop for a few days. I'm yet to
see an to see if any perfmance regressions (or gains) show up.

Without the last (instrumentation/debugging) patch:

arch/x86/include/asm/mmu_context.h | 6 ++
arch/x86/include/asm/processor.h | 1
arch/x86/kernel/cpu/amd.c | 7 --
arch/x86/kernel/cpu/common.c | 13 ----
arch/x86/kernel/cpu/intel.c | 26 ---------
arch/x86/mm/tlb.c | 106 ++++++++++++++++++-------------------
include/linux/mm_types.h | 8 ++
7 files changed, 68 insertions(+), 99 deletions(-)
[davehans@viggo linux.git]$

--

I originally went to look at this becuase I realized that newer
CPUs were not present in the intel_tlb_flushall_shift_set() code.

I went to try to figure out where to stick newer CPUs (do we
consider them more like SandyBridge or IvyBridge), and was not
able to repeat the original experiments.

Instead, this set does:
1. Rework the code a bit to ready it for tracepoints
2. Add tracepoints
3. Add a new tunable and set it to a sane value
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/