> From: Douglas Anderson <dianders@xxxxxxxxxxxx> > > [ Upstream commit 31b265b3baaf55f209229888b7ffea523ddab366 ] > > As reported back in 2016-11 [1], the "ftdump" kdb command triggers a > BUG for "sleeping function called from invalid context". > > kdb's "ftdump" command wants to call ring_buffer_read_prepare() in > atomic context. A very simple solution for this is to add allocation > flags to ring_buffer_read_prepare() so kdb can call it without > triggering the allocation error. This patch does that. I see solution is simple, but now we have a loop with GFP_ATOMIC allocations inside. How many "tracing spus" is this expected to loop over? Will not it exhaust atomically available pages and reliably fail in common configurations? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
