From 544ecf310f0e7f51fa057ac2a295fc1b3b35a9d3 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 May 2012 15:04:50 -0700 Subject: [PATCH] workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active worker_enter_idle() has WARN_ON_ONCE() which triggers if nr_running isn't zero when every worker is idle. This can trigger spuriously while a cpu is going down due to the way trustee sets %WORKER_ROGUE and zaps nr_running. It first sets %WORKER_ROGUE on all workers without updating nr_running, releases gcwq->lock, schedules, regrabs gcwq->lock and then zaps nr_running. If the last running worker enters idle inbetween, it would see stale nr_running which hasn't been zapped yet and trigger the WARN_ON_ONCE(). Fix it by performing the sanity check iff the trustee is idle. Signed-off-by: Tejun Heo Reported-by: "Paul E. McKenney" Cc: stable@vger.kernel.org --- Reading git-format-patch failed