On Tue, Dec 06 2022, Derrick Stolee wrote: > On 12/1/2022 7:25 AM, Tao Klerks wrote: >> But my *question* is: Does anyone know where I could/should look to >> understand why the GC was happening in the foreground, even though the >> message says it will run in the background? > > On Windows, Git's foreground process cannot complete without also > killing the background process. I'm not sure on the concrete details, > but the lack of a background "git gc --auto" here is deliberate for > that platform. > >> I don't know how to create the conditions for the auto-GC on demand >> (how to create lots of loose objects??), so I don't know how to verify >> whether it ever runs in the background on Windows, or what that might >> depend on. I saw some discussions in 2016, but I can't tell what the >> conclusion was; is it simply the case that git has been "lying" about >> running GC in the background, on windows, for all these years? Or is >> there something specific going on in this user's environment? > > Instead, the modern recommendation for repositories where "git gc --auto" > would be slow is to run "git maintenance start" which will schedule > background maintenance jobs with the Windows scheduler. Those processes > are built to do updates that are non-invasive to concurrent foreground > processes. It also sets config to avoid "git gc --auto" commands at the > end of foreground Git processes. > > See [1] for more details. > > [1] https://git-scm.com/docs/git-maintenance That's good advice, but Tao is pointing out that the message we emit is buggy here, which is a correct. The problem is just that on Windows we always fail to daemonize(), but didn't correct the bits that know that to the bits that emit the message. I think this should fix it: diff --git a/builtin/gc.c b/builtin/gc.c index 02455fdcd73..a5f599ebff0 100644 --- a/builtin/gc.c +++ b/builtin/gc.c @@ -623,9 +623,11 @@ int cmd_gc(int argc, const char **argv, const char *prefix) if (!need_to_gc()) return 0; if (!quiet) { +#ifndef NO_POSIX_GOODIES if (detach_auto) fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n")); else +#endif fprintf(stderr, _("Auto packing the repository for optimum performance.\n")); fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n")); } Tao: If you're interested do you mind carrying that (or some other similar) patch forward? The above is: Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
