xmmap: inform Linux users of tuning knobs on ENOMEM

Linux users may benefit from additional information on how to
avoid ENOMEM from mmap despite the system having enough RAM to
accomodate them.  We can't reliably unmap pack windows to work
around the issue since malloc and other library routines may
mmap without our knowledge.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/config.c b/config.c
index f9c400ad30..79ae9f2dea 100644
--- a/config.c
+++ b/config.c
@@ -3051,7 +3051,8 @@ int git_config_set_multivar_in_file_gently(const char *config_filename,
 		if (contents == MAP_FAILED) {
 			if (errno == ENODEV && S_ISDIR(st.st_mode))
 				errno = EISDIR;
-			error_errno(_("unable to mmap '%s'"), config_filename);
+			error_errno(_("unable to mmap '%s'%s"),
+					config_filename, mmap_os_err());
 			ret = CONFIG_INVALID_FILE;
 			contents = NULL;
 			goto out_free;