Commit d1969a84 authored Jan 16, 2014 by Hugh Dickins Committed by Linus Torvalds Jan 17, 2014

percpu_counter: unbreak __percpu_counter_add()



Commit 74e72f89 ("lib/percpu_counter.c: fix __percpu_counter_add()")
looked very plausible, but its arithmetic was badly wrong: obvious once
you see the fix, but maddening to get there from the weird tmpfs ENOSPCs

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Fan Du <fan.du@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 85ce70fd

lib/percpu_counter.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -82,7 +82,7 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
		unsigned long flags;
		raw_spin_lock_irqsave(&fbc->lock, flags);
		fbc->count += count;
		__this_cpu_sub(*fbc->counters, count);
		__this_cpu_sub(*fbc->counters, count - amount);
		raw_spin_unlock_irqrestore(&fbc->lock, flags);
		} else {
		this_cpu_add(*fbc->counters, amount);