On 7/18/22 12:46 PM, Teng Long wrote:
When we specify GIT_TRACE2_CONFIG_PARAMS or trace2.configparams,
trace2 will prints "interesting" config values to log. Sometimes,
when a config set in multiple scope files, the following output
looks like (the irrelevant fields are omitted here as "..."):
...| def_param | ... | core.multipackindex:false
...| def_param | ... | core.multipackindex:false
...| def_param | ... | core.multipackindex:false
As the log shows, even each config in different scope is dumped, but
we don't know which scope it comes from. Therefore, it's better to
add the scope names as well to make them be more recognizable. For
example, when execute:
$ GIT_TRACE2_PERF=1 \
> GIT_TRACE2_CONFIG_PARAMS=core.multipackIndex \
> git rev-list --test-bitmap HEAD"
The following is the ouput (the irrelevant fields are omitted here
as "..."):
Format normal:
... git.c:461 ... def_param scope:system core.multipackindex=false
... git.c:461 ... def_param scope:global core.multipackindex=false
... git.c:461 ... def_param scope:local core.multipackindex=false
Format perf:
... | def_param | ... | scope:system | core.multipackindex:false
... | def_param | ... | scope:global | core.multipackindex:false
... | def_param | ... | scope:local | core.multipackindex:false
Format event:
{"event":"def_param", ... ,"scope":"system","param":"core.multipackindex","value":"false"}
{"event":"def_param", ... ,"scope":"global","param":"core.multipackindex","value":"false"}
{"event":"def_param", ... ,"scope":"local","param":"core.multipackindex","value":"false"}
Signed-off-by: Teng Long <dyroneteng@xxxxxxxxx>
---
Documentation/technical/api-trace2.txt | 45 ++++++++++++++++++++++++++
trace2/tr2_tgt_event.c | 3 ++
trace2/tr2_tgt_normal.c | 5 ++-
trace2/tr2_tgt_perf.c | 9 ++++--
4 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index bb13ca3db8..48205a5ac5 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -1207,6 +1207,51 @@ at offset 508.
This example also shows that thread names are assigned in a racy manner
as each thread starts and allocates TLS storage.
+Print Configs::
+
+ Dump "interesting" config values to trace2 log.
++
+The environment variable `GIT_TRACE2_CONFIG_PARAMS` and configuration
+`trace2.configparams` can be used to output config values which you care
+about. For example, assume that we want to config different `color.ui`
+values in multiple scopes, such as:
++
+----------------
+$ git config --system color.ui never
+$ git config --global color.ui always
+$ git config --local color.ui auto
+$ git config --list --show-scope | grep 'color.ui'
+system color.ui=never
+global color.ui=always
+local color.ui=auto
+----------------
++
+Then, mark the config `color.ui` as "interesting" config with
+`GIT_TRACE2_CONFIG_PARAMS`:
++
+----------------
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
+$ export GIT_TRACE2_CONFIG_PARAMS=color.ui
+$ git version
+...
+$ cat ~/log.perf
+d0 | main | version | | | | | ...
+d0 | main | start | | 0.000284 | | | /opt/git/master/bin/git version
+d0 | main | cmd_ancestry | | | | | ancestry:[bash sshd sshd sshd systemd]
+d0 | main | cmd_name | | | | | version (version)
+d0 | main | exit | | 0.000419 | | | code:0
+d0 | main | atexit | | 0.000426 | | | code:0
+d0 | main | version | | | | | ...
+d0 | main | start | | 0.000275 | | | /opt/git/master/bin/git version
+d0 | main | cmd_ancestry | | | | | ancestry:[bash sshd sshd sshd systemd]
+d0 | main | cmd_name | | | | | version (version)
+d0 | main | def_param | | | | | color.ui:never
+d0 | main | def_param | | | | | color.ui:always
+d0 | main | def_param | | | | | color.ui:auto
shouldn't this example in the docs have the scope value in the
next to last column as you noted in the cover letter ?
+d0 | main | exit | | 0.000543 | | | code:0
+d0 | main | atexit | | 0.000549 | | | code:0
+----------------
== Future Work
...
Otherwise, this all LGTM.
Thanks
Jeff
