On February 18, 2019 15:47, I wrote: > On February 18, 2019 15:41, Johannes Schindelin wrote: > > On Thu, 14 Feb 2019, Randall S. Becker wrote: > > > > > On February 14, 2019 17:39, Junio C Hamano wrote: > > > > To: Randall S. Becker <rsbecker@xxxxxxxxxxxxx> > > > > Cc: 'Johannes Schindelin via GitGitGadget' > > > > <gitgitgadget@xxxxxxxxx>; git@xxxxxxxxxxxxxxx; 'Max Kirillov' > > > > <max@xxxxxxxxxx> > > > > Subject: Re: [PATCH 0/1] Fix hang in t5562, introduced in > > > > v2.21.0-rc1 > > > > > > > > "Randall S. Becker" <rsbecker@xxxxxxxxxxxxx> writes: > > > > > > > > > Unfortunately, subtest 13 still hangs on NonStop, even with this > > > > > patch, so our Pipeline still hangs. I'm glad it's better on > > > > > Azure, but I don't think this actually addresses the root cause > > > > > of the > hang. > > > > > > > > Sigh. > > > > > > > > > possible this is not the test that is failing, but actually the > > > > > git-http-backend? The code is not in a loop, if that helps. It > > > > > is not consuming any significant cycles. I don't know that part > > > > > of the code at all, sadly. The code is here: > > > > > > > > > > * in the operating system from here up * > > > > > cleanup_children + 0x5D0 (UCr) > > > > > cleanup_children_on_exit + 0x70 (UCr) > > > > > git_atexit_dispatch + 0x200 (UCr) > > > > > __process_atexit_functions + 0xA0 (DLL zcredll) > > > > > CRE_TERMINATOR_ + 0xB50 (DLL zcredll) > > > > > exit + 0x2A0 (DLL zcrtldll) > > > > > die_webcgi + 0x240 (UCr) > > > > > die_errno + 0x360 (UCr) > > > > > write_or_die + 0x1C0 (UCr) > > > > > end_headers + 0x1A0 (UCr) > > > > > die_webcgi + 0x220 (UCr) > > > > > die + 0x320 (UCr) > > > > > inflate_request + 0x520 (UCr) > > > > > run_service + 0xC20 (UCr) > > > > > service_rpc + 0x530 (UCr) > > > > > cmd_main + 0xD00 (UCr) > > > > > main + 0x190 (UCr) > > > > > > > > > > Best guess is that a signal (SIGCHLD?) is possibly getting eaten > > > > > or neglected somewhere between the test, perl, and git-http- > backend. > > > > > > > > So we are trying to die(), which actually happens in die_webcgi(), > > > > and > > > then try > > > > to write some message _but_ notice an error inside > > > > write_or_dir() and try to exit because we do not want to recurse > > > > forever trying to die, giving a message to say how/why we died, > > > > and die because failing to give that message, forever. > > > > > > > > But in our attempt to exit(), we try to "cleanup children" and > > > > that is > > > what gets > > > > stuck. > > > > > > > > One big difference before and after the /dev/zero change is that > > > > the > > > process > > > > is now on a downstream of the pipe. If we prepare a large file > > > > with a > > > finite > > > > size full of NULs and replace /dev/null with it, instead of > > > > feeding NULs > > > from > > > > the pipe, would it change the equation? > > > > > > Doubtful. The processes are still around, and are waiting on read > > > but not actively reading (CPU time is not going up, so we're not > > > reading an infinite stream). To me, this is a pipe situation where > > > there is simply nothing waiting on the pipe (maybe a flush > > > missing?). I'm grasping are straws without knowing the actual > > > process architecture of > the > > test to debug it. > > > > So could you try with this patch? > > > > -- snipsnap -- > > diff --git a/http-backend.c b/http-backend.c index > > d5cea0329a..7c1b4a2555 > > 100644 > > --- a/http-backend.c > > +++ b/http-backend.c > > @@ -427,6 +427,7 @@ static void inflate_request(const char *prog_name, > > int out, int buffer_input, ss > > > > done: > > git_inflate_end(&stream); > > + close(0); > > close(out); > > free(full_request); > > } > > In isolation or with the other fixes associated with t5562? Or, which baseline > commit should I use? 8989e1950a or d92031209a or some other? It works fine based off of d92031209a - the test actually runs a bit faster based on the wall clock.
