[lttng-dev] [PATCH lttng-tools v2] Fix: COMPAT_EPOLL_PROC_PATH is available from Linux 2.6.28

Jonathan Rajotte jonathan.rajotte-julien at efficios.com
Tue May 9 19:46:35 UTC 2017


v2: Typo in commit message "per see" -> "per se"

Failing on opening [1] is not an error per se. [1] was
introduced in Linux 2.6.28 but epoll is available since
2.5.44. Hence, goto end and set a default value without
setting error return value.

[1] /proc/sys/fs/epoll/max_user_watches

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
---
 src/common/compat/compat-epoll.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/common/compat/compat-epoll.c b/src/common/compat/compat-epoll.c
index dbaf6823..6a781c7a 100644
--- a/src/common/compat/compat-epoll.c
+++ b/src/common/compat/compat-epoll.c
@@ -301,7 +301,15 @@ int compat_epoll_set_max_size(void)
 
 	fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
 	if (fd < 0) {
-		retval = -1;
+		/*
+		 * Failing on opening [1] is not an error per see. [1] was
+		 * introduced in Linux 2.6.28 but epoll is available since
+		 * 2.5.44. Hence, goto end and set a default value without
+		 * setting an error return value.
+		 *
+		 * [1] /proc/sys/fs/epoll/max_user_watches
+		 */
+		retval = 0;
 		goto end;
 	}
 
-- 
2.11.0



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