[PATCH v2 10/10] af_unix: use freezable blocking calls in read

From: Colin Cross
Date: Wed May 01 2013 - 21:35:57 EST


Avoid waking up every thread sleeping in read call on an AF_UNIX
socket during suspend and resume by calling a freezable blocking
call. Previous patches modified the freezer to avoid sending
wakeups to threads that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
---
net/unix/af_unix.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 2db702d..2bcac57 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -114,6 +114,7 @@
#include <linux/mount.h>
#include <net/checksum.h>
#include <linux/security.h>
+#include <linux/freezer.h>

struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
EXPORT_SYMBOL_GPL(unix_socket_table);
@@ -1880,7 +1881,7 @@ static long unix_stream_data_wait(struct sock *sk, long timeo)

set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
unix_state_unlock(sk);
- timeo = schedule_timeout(timeo);
+ timeo = freezable_schedule_timeout(timeo);
unix_state_lock(sk);
clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
}
--
1.8.2.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/