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| author | Arthur Hanson Rasmusson <arthur@vgpu.io> | 2026-09-29 14:47:17 -0400 |
|---|---|---|
| committer | Arthur Hanson Rasmusson <arthur@vgpu.io> | 2026-09-29 14:47:17 -0400 |
| commit | fdeb1d4ba62283210dc259141da4da024bd1cc77 (patch) | |
| tree | 830c3b759238d37eeb24d2bde22454f5e70acaa2 /tools/guest-diag/semfix_watch.py | |
| parent | a83a42df71c235c5f9f8eaeb3b62053a75fe30c7 (diff) | |
| download | open-iov-fdeb1d4ba62283210dc259141da4da024bd1cc77.tar.gz open-iov-fdeb1d4ba62283210dc259141da4da024bd1cc77.zip | |
guest-diag: cheaper trace read, optional push sampler, bigger pagemap batches
Under load the semfix poll grepped the whole (growing) trace file and the
track_waits push block spawned three guest processes per sample, both of
which slowed the pin path into the client's failure window. The trace read
now tails 128 KB; track_waits.sh gates the push dump behind PUSH=0; the
pagemap helper reads 32 KB chunks.
Diffstat (limited to 'tools/guest-diag/semfix_watch.py')
| -rw-r--r-- | tools/guest-diag/semfix_watch.py | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/guest-diag/semfix_watch.py b/tools/guest-diag/semfix_watch.py index 400fafe..347da5e 100644 --- a/tools/guest-diag/semfix_watch.py +++ b/tools/guest-diag/semfix_watch.py @@ -145,7 +145,8 @@ def guest_trace(): Read *before* clearing: the create-time probes fire once per client and would be wiped by a clear that races them. """ - inner = ("grep -E \"uvmt|uvch|uvbp|uvpbf\" /sys/kernel/tracing/trace " + inner = ("tail -c 131072 /sys/kernel/tracing/trace " + "| grep -E \"uvmt|uvch|uvbp|uvpbf\" " "| tail -400") if not os.environ.get("KEEP_TRACE"): inner += "; echo > /sys/kernel/tracing/trace" |