Commit 2b15af6f authored May 06, 2013 by Colin Cross Committed by Rafael J. Wysocki May 12, 2013

af_unix: use freezable blocking calls in read



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.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent a2d5f1f5

net/unix/af_unix.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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);
		@@ -1879,7 +1880,7 @@ 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);
		}

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