Thank you for advices. This version doesn't use inlined function
and adds no overhead in 64bit.
Info:
res_counter_read_u64 is not frequently called in memcontrol.c now.
It's called at user-interface and interaction with other components.
This addition of lock will not add any performance troubles.
==
res_counter_read_u64 reads u64 value without lock. It's dangerous
in 32bit environment. This patch adds lock.
Changelog:
- handle 32/64 bit in other funciton
- avoid unnecessary inlining.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
kernel/res_counter.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
Index: mmotm-0125/kernel/res_counter.c
===================================================================
--- mmotm-0125.orig/kernel/res_counter.c
+++ mmotm-0125/kernel/res_counter.c
@@ -126,10 +126,24 @@ ssize_t res_counter_read(struct res_coun
pos, buf, s - buf);
}
+#if BITS_PER_LONG == 32
+u64 res_counter_read_u64(struct res_counter *counter, int member)
+{
+ unsigned long flags;
+ u64 ret;
+
+ spin_lock_irqsave(&counter->lock, flags);
+ ret = *res_counter_member(counter, member);
+ spin_unlock_irqrestore(&counter->lock, flags);
+
+ return ret;
+}
+#else
u64 res_counter_read_u64(struct res_counter *counter, int member)
{
return *res_counter_member(counter, member);
}
+#endif
int res_counter_memparse_write_strategy(const char *buf,
unsigned long long *res)
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>