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Re: [Qemu-devel] [PATCH 0/2] Reduce lock contention on TCG hot-path
From: |
Emilio G. Cota |
Subject: |
Re: [Qemu-devel] [PATCH 0/2] Reduce lock contention on TCG hot-path |
Date: |
Fri, 1 Jul 2016 20:52:29 -0400 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Fri, Jul 01, 2016 at 17:16:08 +0100, Alex Bennée wrote:
(snip)
> run 1: ret=0 (PASS), time=4.755824 (1/1)
> run 2: ret=0 (PASS), time=4.756076 (2/2)
> run 3: ret=0 (PASS), time=4.755916 (3/3)
> run 4: ret=0 (PASS), time=4.755853 (4/4)
> run 5: ret=0 (PASS), time=4.755929 (5/5)
> Results summary:
> 0: 5 times (100.00%), avg time 4.755920 (0.000000 deviation)
(snip)
> run 1: ret=0 (PASS), time=9.761559 (1/1)
> run 2: ret=0 (PASS), time=9.511616 (2/2)
> run 3: ret=0 (PASS), time=9.761713 (3/3)
> run 4: ret=0 (PASS), time=10.262504 (4/4)
> run 5: ret=0 (PASS), time=9.762059 (5/5)
> Results summary:
> 0: 5 times (100.00%), avg time 9.811890 (0.060150 deviation)
This is a needless diversion, but I was explaining this stuff today
to a student so couldn't help but notice.
The computed deviations seem overly small. For instance, the corrected sample
standard deviation ( https://en.wikipedia.org/wiki/Standard_deviation )
(which is usually referred to as "standard deviation", or "error")
for the last test should be 0.2742 instead of 0.06.
How are they being computed? I tried to find the source of your script
(in the kvm-unit-tests repo) but couldn't find it.
Thanks,
Emilio
- Re: [Qemu-devel] [PATCH 2/2] cpu-exec: remove tb_lock from the hot-path, (continued)
[Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Alex Bennée, 2016/07/01
- Re: [Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Richard Henderson, 2016/07/01
- Re: [Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Emilio G. Cota, 2016/07/01
- Re: [Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Alex Bennée, 2016/07/02
- Re: [Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Emilio G. Cota, 2016/07/04
- Re: [Qemu-devel] [PATCH 1/2] tcg: Ensure safe tb_jmp_cache lookup out of 'tb_lock', Paolo Bonzini, 2016/07/05
Re: [Qemu-devel] [PATCH 0/2] Reduce lock contention on TCG hot-path,
Emilio G. Cota <=