wrapper: use trace2 counters to collect fsync stats
As mentioned in the thread starting at [1], trace2 counters should be used to count events instead of ad-hoc static variables. Convert the two fsync static variables to trace2 counters, reducing the coupling between wrapper.c and the trace2 subsystem. Adjust t/t5351 to match the trace2 counter output format. The counters are not per-thread because the ones being replaced also were not. [1] https://lore.kernel.org/git/20230627195251.1973421-2-calvinwan@google.com/ Signed-off-by: Beat Bolli <dev+git@drbeat.li> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Beat Bolli committed
Jul 20, 2023 at 18:48 UTC
a27eecea75b3858b4052b191143f144a7e966869
6 files changed
+19
-26
t/t5351-unpack-large-objects.sh
+3
-3
@@ -55,7 +55,7 @@ check_fsync_events () {
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cat >expect &&
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sed -n \
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- -e '/^{"event":"data",.*"category":"fsync",/ {
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+ -e '/^{"event":"counter",.*"category":"fsync",/ {
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s/.*"category":"fsync",//;
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s/}$//;
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p;
@@ -78,8 +78,8 @@ test_expect_success 'unpack big object in stream (core.fsyncmethod=batch)' '
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flush_count=1
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fi &&
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check_fsync_events trace2.txt <<-EOF &&
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- "key":"fsync/writeout-only","value":"6"
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- "key":"fsync/hardware-flush","value":"$flush_count"
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+ "name":"writeout-only","count":6
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+ "name":"hardware-flush","count":$flush_count
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EOF
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test_dir_is_empty dest.git/objects/pack &&
trace2.c
-1
@@ -276,7 +276,6 @@ void trace2_cmd_exit_fl(const char *file, int line, int code)
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if (!trace2_enabled)
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return;
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- trace_git_fsync_stats();
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trace2_collect_process_info(TRACE2_PROCESS_INFO_EXIT);
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tr2main_exit_code = code;
trace2.h
+4
@@ -552,6 +552,10 @@ enum trace2_counter_id {
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TRACE2_COUNTER_ID_TEST1 = 0, /* emits summary event only */
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TRACE2_COUNTER_ID_TEST2, /* emits summary and thread events */
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+ /* counts number of fsyncs */
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+ TRACE2_COUNTER_ID_FSYNC_WRITEOUT_ONLY,
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+ TRACE2_COUNTER_ID_FSYNC_HARDWARE_FLUSH,
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+
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/* Add additional counter definitions before here. */
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TRACE2_NUMBER_OF_COUNTERS
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};
trace2/tr2_ctr.c
+10
@@ -27,6 +27,16 @@ static struct tr2_counter_metadata tr2_counter_metadata[TRACE2_NUMBER_OF_COUNTER
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.name = "test2",
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.want_per_thread_events = 1,
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},
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+ [TRACE2_COUNTER_ID_FSYNC_WRITEOUT_ONLY] = {
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+ .category = "fsync",
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+ .name = "writeout-only",
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+ .want_per_thread_events = 0,
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+ },
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+ [TRACE2_COUNTER_ID_FSYNC_HARDWARE_FLUSH] = {
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+ .category = "fsync",
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+ .name = "hardware-flush",
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+ .want_per_thread_events = 0,
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+ },
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/* Add additional metadata before here. */
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};
wrapper.c
+2
-17
@@ -10,9 +10,6 @@
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#include "strbuf.h"
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#include "trace2.h"
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-static intmax_t count_fsync_writeout_only;
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-static intmax_t count_fsync_hardware_flush;
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-
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#ifdef HAVE_RTLGENRANDOM
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/* This is required to get access to RtlGenRandom. */
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#define SystemFunction036 NTAPI SystemFunction036
@@ -551,7 +548,7 @@ int git_fsync(int fd, enum fsync_action action)
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{
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switch (action) {
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case FSYNC_WRITEOUT_ONLY:
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- count_fsync_writeout_only += 1;
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+ trace2_counter_add(TRACE2_COUNTER_ID_FSYNC_WRITEOUT_ONLY, 1);
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#ifdef __APPLE__
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/*
@@ -583,7 +580,7 @@ int git_fsync(int fd, enum fsync_action action)
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return -1;
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case FSYNC_HARDWARE_FLUSH:
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- count_fsync_hardware_flush += 1;
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+ trace2_counter_add(TRACE2_COUNTER_ID_FSYNC_HARDWARE_FLUSH, 1);
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/*
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* On macOS, a special fcntl is required to really flush the
@@ -600,18 +597,6 @@ int git_fsync(int fd, enum fsync_action action)
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}
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}
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-static void log_trace_fsync_if(const char *key, intmax_t value)
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-{
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- if (value)
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- trace2_data_intmax("fsync", the_repository, key, value);
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-}
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-
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-void trace_git_fsync_stats(void)
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-{
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- log_trace_fsync_if("fsync/writeout-only", count_fsync_writeout_only);
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- log_trace_fsync_if("fsync/hardware-flush", count_fsync_hardware_flush);
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-}
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-
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static int warn_if_unremovable(const char *op, const char *file, int rc)
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{
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int err;
wrapper.h
-5
@@ -87,11 +87,6 @@ enum fsync_action {
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*/
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int git_fsync(int fd, enum fsync_action action);
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-/*
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- * Writes out trace statistics for fsync using the trace2 API.
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- */
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-void trace_git_fsync_stats(void);
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-
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/*
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* Preserves errno, prints a message, but gives no warning for ENOENT.
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* Returns 0 on success, which includes trying to unlink an object that does