http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60295
--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
lto_wpa_write_files has
for (i = 0; i < n_sets; i++)
{
...
stream_out (temp_filename, part->encoder, i == n_sets - 1);
...
}
n_sets is 32 when bootstrapping GCC. With parallel build, we
may build cc1, cc1plus, f951, cc1obj at the same time. If machine
is under heavy load, we may start 4*32 == 128 lto1-wpa-stream
processes at the same time with -flto=jobserver. This patch:
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index c676d79..4023036 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -3219,9 +3219,7 @@ do_whole_program_analysis (void)
lto_parallelism = 1;
/* TODO: jobserver communicatoin is not supported, yet. */
- if (!strcmp (flag_wpa, "jobserver"))
- lto_parallelism = -1;
- else
+ if (strcmp (flag_wpa, "jobserver"))
{
lto_parallelism = atoi (flag_wpa);
if (lto_parallelism <= 0)
limits lto1-wpa-stream process to 1 if -flto=jobserver is used.
