From: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
Add some global trace2 statistics for the number of fsyncs performed
during the lifetime of a Git process.
These stats are printed as part of trace2_cmd_exit_fl, which is
presumably where we might want to print any other cross-cutting
statistics.
Signed-off-by: Neeraj Singh <neerajsi@xxxxxxxxxxxxx>
---
trace2: add stats for fsync operations
Add some global trace2 statistics for the number of fsyncs performed
during the lifetime of a Git process.
These stats are printed as part of trace2_cmd_exit_fl, which is
presumably where we might want to print any other cross-cutting
statistics.
Signed-off-by: Neeraj Singh neerajsi@xxxxxxxxxxxxx
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1192%2Fneerajsi-msft%2Fns%2Ftrace2-fsync-stats-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1192/neerajsi-msft/ns/trace2-fsync-stats-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1192
git-compat-util.h | 5 +++++
t/t0211/scrub_perf.perl | 4 ++++
trace2.c | 1 +
wrapper.c | 12 ++++++++++++
4 files changed, 22 insertions(+)
diff --git a/git-compat-util.h b/git-compat-util.h
index 0892e209a2f..4d444dca274 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -1281,6 +1281,11 @@ enum fsync_action {
*/
int git_fsync(int fd, enum fsync_action action);
+/*
+ * Writes out trace statistics for fsync using the trace2 API.
+ */
+void trace_git_fsync_stats(void);
+
/*
* Preserves errno, prints a message, but gives no warning for ENOENT.
* Returns 0 on success, which includes trying to unlink an object that does
diff --git a/t/t0211/scrub_perf.perl b/t/t0211/scrub_perf.perl
index d164b750ff7..299999f0f89 100644
--- a/t/t0211/scrub_perf.perl
+++ b/t/t0211/scrub_perf.perl
@@ -59,6 +59,10 @@ while (<>) {
# and highly variable. Just omit them.
goto SKIP_LINE;
}
+ if ($tokens[$col_category] =~ m/fsync/) {
+ # fsync events aren't interesting for the test
+ goto SKIP_LINE;
+ }
}
# t_abs and t_rel are either blank or a float. Replace the float
diff --git a/trace2.c b/trace2.c
index 179caa72cfe..e01cf77f1a8 100644
--- a/trace2.c
+++ b/trace2.c
@@ -214,6 +214,7 @@ int trace2_cmd_exit_fl(const char *file, int line, int code)
if (!trace2_enabled)
return code;
+ trace_git_fsync_stats();
trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
tr2main_exit_code = code;
diff --git a/wrapper.c b/wrapper.c
index 354d784c034..f512994690b 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -4,6 +4,9 @@
#include "cache.h"
#include "config.h"
+static intmax_t count_fsync_writeout_only;
+static intmax_t count_fsync_hardware_flush;
+
#ifdef HAVE_RTLGENRANDOM
/* This is required to get access to RtlGenRandom. */
#define SystemFunction036 NTAPI SystemFunction036
@@ -564,6 +567,7 @@ int git_fsync(int fd, enum fsync_action action)
{
switch (action) {
case FSYNC_WRITEOUT_ONLY:
+ count_fsync_writeout_only += 1;
#ifdef __APPLE__
/*
@@ -595,6 +599,8 @@ int git_fsync(int fd, enum fsync_action action)
return -1;
case FSYNC_HARDWARE_FLUSH:
+ count_fsync_hardware_flush += 1;
+
/*
* On macOS, a special fcntl is required to really flush the
* caches within the storage controller. As of this writing,
@@ -610,6 +616,12 @@ int git_fsync(int fd, enum fsync_action action)
}
}
+void trace_git_fsync_stats(void)
+{
+ trace2_data_intmax("fsync", the_repository, "fsync/writeout-only", count_fsync_writeout_only);
+ trace2_data_intmax("fsync", the_repository, "fsync/hardware-flush", count_fsync_hardware_flush);
+}
+
static int warn_if_unremovable(const char *op, const char *file, int rc)
{
int err;
base-commit: c54b8eb302ffb72f31e73a26044c8a864e2cb307
--
gitgitgadget
