DescriptionCreate a field trial to test if we can detect good QPC implementations.
We'd like to use QPC (TimeTicks::HighResNow) for all uses of TimeTicks. It's
likely this will only work on some subset of Windows systems. This field trial
is meant to determine if an implementation is good and if our heuristics are
able to detect a good implementation.
This particular CL checks for an Intel CPU parameter that indicates rdtsc is
consistently incremented. Firefox uses the same check. I hope to determine that
this is in fact correct and on which versions of Windows QPC calls rdtsc
directly.
We can add more heuristics later.
BUG=158234
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=197431
Patch Set 1 #
Total comments: 4
Patch Set 2 : Add histograms #Patch Set 3 : Really add histograms #
Total comments: 6
Patch Set 4 : Try to force a core change #
Total comments: 6
Patch Set 5 : Rename to experiment #
Total comments: 2
Patch Set 6 : Skip XP #Patch Set 7 : Dynamically find GetCurrentProcessorNumber function #
Total comments: 3
Patch Set 8 : Restore affinity at the end #
Total comments: 2
Patch Set 9 : Use chrome namespace #Patch Set 10 : Fix win64 #Patch Set 11 : Revert histogram fix #Patch Set 12 : Rebase #
Messages
Total messages: 29 (0 generated)
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