[PATCH v2 04/10] binder: use freezable blocking calls

From: Colin Cross
Date: Wed May 01 2013 - 21:40:53 EST


Avoid waking up every thread sleeping in a binder call 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>
---
drivers/staging/android/binder.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 24456a0..af8fba4 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -20,6 +20,7 @@
#include <asm/cacheflush.h>
#include <linux/fdtable.h>
#include <linux/file.h>
+#include <linux/freezer.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
@@ -2140,13 +2141,13 @@ retry:
if (!binder_has_proc_work(proc, thread))
ret = -EAGAIN;
} else
- ret = wait_event_interruptible_exclusive(proc->wait, binder_has_proc_work(proc, thread));
+ ret = wait_event_freezable_exclusive(proc->wait, binder_has_proc_work(proc, thread));
} else {
if (non_block) {
if (!binder_has_thread_work(thread))
ret = -EAGAIN;
} else
- ret = wait_event_interruptible(thread->wait, binder_has_thread_work(thread));
+ ret = wait_event_freezable(thread->wait, binder_has_thread_work(thread));
}

binder_lock(__func__);
--
1.8.2.1

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