From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>
A major speed regression in trace-cmd v2.8 is reported by Johannes Berg
when parsing a huge trace.dat file:
"I have a ~1.7G file with just under 620k events (not exactly big by our standards),
and parsing speed (with -N to disable plugins) goes from ~4.5 seconds on commit
1ad32c24746 to >>4.5 minutes (I aborted there) on master.
I was talking to Steven about another issue, and he pointed me to
commit c2fc2bc296f7. Reverting that on master makes it take ~2 seconds,
so that'd actually be an improvement."
Proposed solution: do not free pages from "struct page **pages" lookup table
in struct cpu_data, in case a trace file is loaded. This reverts the behavior
for this use case, as it was before commit c2fc2bc296f7.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203411
Fixes: c2fc2bc296f7 ("trace-cmd: Fix crash when trace-cmd is executed with args profile -F sleep 1")
Reported-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
lib/trace-cmd/trace-input.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 7acecf3..32af20c 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -987,15 +987,17 @@ static void __free_page(struct tracecmd_input *handle, struct page *page)
free(page);
- for (index = cpu_data->nr_pages - 1; index > 0; index--)
- if (cpu_data->pages[index])
- break;
- if (index < (cpu_data->nr_pages - 1)) {
- pages = realloc(cpu_data->pages, (index + 1) * sizeof(*cpu_data->pages));
- if (!pages)
- return;
- cpu_data->pages = pages;
- cpu_data->nr_pages = index + 1;
+ if (handle->use_pipe) {
+ for (index = cpu_data->nr_pages - 1; index > 0; index--)
+ if (cpu_data->pages[index])
+ break;
+ if (index < (cpu_data->nr_pages - 1)) {
+ pages = realloc(cpu_data->pages, (index + 1) * sizeof(*cpu_data->pages));
+ if (!pages)
+ return;
+ cpu_data->pages = pages;
+ cpu_data->nr_pages = index + 1;
+ }
}
}
--
2.21.0
|