On Tue, Feb 12, 2019 at 11:21:29AM +0100, Michal Hocko wrote: > From: Michal Hocko <[email protected]> > > Tetsuo has reported that creating a thousands of processes sharing MM > without SIGHAND (aka alien threads) and setting > /proc/<pid>/oom_score_adj will swamp the kernel log and takes ages [1] > to finish. This is especially worrisome that all that printing is done > under RCU lock and this can potentially trigger RCU stall or softlockup > detector. > > The primary reason for the printk was to catch potential users who might > depend on the behavior prior to 44a70adec910 ("mm, oom_adj: make sure > processes sharing mm have same view of oom_score_adj") but after more > than 2 years without a single report I guess it is safe to simply remove > the printk altogether. > > The next step should be moving oom_score_adj over to the mm struct and > remove all the tasks crawling as suggested by [2] > > [1] > http://lkml.kernel.org/r/[email protected] > [2] http://lkml.kernel.org/r/[email protected] > Reported-by: Tetsuo Handa <[email protected]> > Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
