[PATCH 05/10] res_counter: allow charge failure pointer to be null

From: Frederic Weisbecker
Date: Tue Jan 31 2012 - 22:38:22 EST


So that callers of res_counter_charge() don't have to create and pass this
pointer even if they aren't interested in it.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Paul Menage <paul@xxxxxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Aditya Kali <adityakali@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Tim Hockin <thockin@xxxxxxxxxx>
Cc: Tejun Heo <htejun@xxxxxxxxx>
Cc: Containers <containers@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Glauber Costa <glommer@xxxxxxxxx>
Cc: Cgroups <cgroups@xxxxxxxxxxxxxxx>
Cc: Daniel J Walsh <dwalsh@xxxxxxxxxx>
Cc: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Max Kellermann <mk@xxxxxxxxxx>
Cc: Mandeep Singh Baines <msb@xxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/res_counter.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 6dc6164..d2fc4cd 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -43,14 +43,16 @@ int res_counter_charge_until(struct res_counter *counter,
unsigned long flags;
struct res_counter *c, *u;

- *limit_fail_at = NULL;
+ if (limit_fail_at)
+ *limit_fail_at = NULL;
local_irq_save(flags);
for (c = counter; c != limit; c = c->parent) {
spin_lock(&c->lock);
ret = res_counter_charge_locked(c, val);
spin_unlock(&c->lock);
if (ret < 0) {
- *limit_fail_at = c;
+ if (limit_fail_at)
+ *limit_fail_at = c;
goto undo;
}
}
--
1.7.5.4

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