Hi Shakeel, On Wed, Feb 07, 2018 at 07:44:08AM -0800, Shakeel Butt wrote: > On Sat, Feb 3, 2018 at 12:23 AM, Johannes Weiner <[email protected]> wrote: > > After the ("a983b5ebee57 mm: memcontrol: fix excessive complexity in > > memory.stat reporting"), we observed slowly upward creeping > > NR_WRITEBACK counts over the course of several days, both the > > per-memcg stats as well as the system counter in e.g. /proc/meminfo. > > > > The conversion from full per-cpu stat counts to per-cpu cached atomic > > stat counts introduced an irq-unsafe RMW operation into the updates. > > > > Most stat updates come from process context, but one notable exception > > is the NR_WRITEBACK counter. While writebacks are issued from process > > context, they are retired from (soft)irq context. > > > > When writeback completions interrupt the RMW counter updates of new > > writebacks being issued, the decs from the completions are lost. > > > > Since the global updates are routed through the joint lruvec API, both > > the memcg counters as well as the system counters are affected. > > > > This patch makes the joint stat and event API irq safe. > > > > Fixes: a983b5ebee57 ("mm: memcontrol: fix excessive complexity in > > memory.stat reporting") > > Debugged-by: Tejun Heo <[email protected]> > > Signed-off-by: Johannes Weiner <[email protected]> > > Should this be considered for stable?
The stable tree is only for fixes to already released kernels, but there is no release containing the faulty patch: $ git describe --tags a983b5ebee57 v4.15-3322-ga983b5ebee57 nor was the faulty patch itself marked for stable. So as long as this fix makes it into 4.16 we should be good.
