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@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Neeraj Singh 2022-03-30 05:06:40 +00:00 committed by Junio C Hamano
parent 805e0a6808
commit 9a4987677d
4 changed files with 22 additions and 0 deletions

View File

@ -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

View File

@ -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

View File

@ -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;

View File

@ -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;