On Tue, 22 Sep 2015 15:16:32 -0700 Greg Thelen <gthelen@xxxxxxxxxx> wrote: > mem_cgroup_read_stat() returns a page count by summing per cpu page > counters. The summing is racy wrt. updates, so a transient negative sum > is possible. Callers don't want negative values: > - mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback. > - oom reports and memory.stat shouldn't show confusing negative usage. > - tree_usage() already avoids negatives. > > Avoid returning negative page counts from mem_cgroup_read_stat() and > convert it to unsigned. Someone please remind me why this code doesn't use the existing percpu_counter library which solved this problem years ago. > for_each_possible_cpu(cpu) and which doesn't iterate across offlined CPUs. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>