On Tue, 2 Feb 2016, Tetsuo Handa wrote: > >From 20b3c1c9ef35547395c3774c6208a867cf0046d4 Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Date: Tue, 2 Feb 2016 16:50:45 +0900 > Subject: [RFC][PATCH] mm, page_alloc: Warn on !__GFP_NOWARN allocation from IRQ context. > > Jan Stancek hit a hard lockup problem due to flood of memory allocation > failure messages which lasted for 10 seconds with IRQ disabled. Printing > traces using warn_alloc_failed() is very slow (which can take up to about > 1 second for each warn_alloc_failed() call). The caller used GFP_NOWARN > inside a loop. If the caller used __GFP_NOWARN, it would not have lasted > for 10 seconds. > Sounds like a ratelimiting issue in warn_alloc_failed() with nopage_rs. Would it be possible under certain configs to tweak this to not be so slow? Unfortunately, I don't think we can get away with adding a conditional to the page allocator hotpath for this, especially if it is only going to suggest a kernel patch :) -- 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>