tsdb: more efficient sorting of postings read from WAL at startup#10500
Merged
codesome merged 2 commits intoprometheus:mainfrom Mar 30, 2022
Merged
tsdb: more efficient sorting of postings read from WAL at startup#10500codesome merged 2 commits intoprometheus:mainfrom
codesome merged 2 commits intoprometheus:mainfrom
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This is pulling the `seriesRefSlice` out of the loop, so the compiler doesn't allocate a new one on the heap every time. Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
As noted by staticcheck, Pool prefers the objects in the pool to have pointer type. This is a little more fiddly to code, but avoids allocation of a wrapper object every time a slice is put into the pool. Removed a comment that said fixing this has a performance penalty: not borne out by benchmarks. Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
codesome
approved these changes
Mar 30, 2022
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/prombench v2.34.0 |
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This PR has the memory leak apparently. I am checking if it is the first one. |
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It seems to take several hours to kick in, which is interesting if it's caused by a change that only runs during startup.
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/prombench cancel |
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Benchmark cancel is in progress. |
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This was something I noticed in passing.
Benchmark stats:
Most of the benefit comes from avoiding slice-to-interface allocation, by pulling the
seriesRefSliceout of the loop, so the compiler doesn't allocate a new one on the heap every time.The second commit to use a pointer type in the
Poolreduces allocations two more orders of magnitude: this is almost invisible in benchmark timings after the first commit, but I couldn't leave it with a staticcheck warning :-)Removed a comment that said fixing this has a performance penalty: not borne out by benchmarks.
Since
benchstatrounded the numbers, the first commit goes to 987 allocs/iter, and the second to 9.