On Mon, Aug 19, 2019 at 12:47:30PM +0200, Petr Mladek wrote: > Some bug report included the same softlockups in flush_tlb_kernel_range() > in regular intervals. Unfortunately was not clear if there was a progress > or not. > > The situation can be simulated with a simply busy loop: > > while (true) > cpu_relax(); > > The softlockup detector produces: > > [ 168.277520] watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [cat:4865] > [ 196.277604] watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [cat:4865] > [ 236.277522] watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [cat:4865] > > One would expect only one softlockup report or several reports with > an increased duration.
Let's just say our expectations differ. > The result is that each softlockup is reported only once unless > another process get scheduled: > > [ 320.248948] watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [cat:4916] Which would greatly confuse me; as the above would have me think the situation got resolved (no more lockups reported) even though it is still very much stuck there. IOW, I don't see how this makes anything better. You're removing information.
