Re: [PATCH] mm: warn about allocations which stall for too long

From: Michal Hocko
Date: Fri Sep 23 2016 - 05:16:24 EST


On Fri 23-09-16 16:44:26, Hillf Danton wrote:
> On Friday, September 23, 2016 4:32 PM, Michal Hocko wrote
> > On Fri 23-09-16 16:29:36, Hillf Danton wrote:
> > [...]
> > > > @@ -3659,6 +3661,15 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
> > > > else
> > > > no_progress_loops++;
> > > >
> > > > + /* Make sure we know about allocations which stall for too long */
> > > > + if (!(gfp_mask & __GFP_NOWARN) && time_after(jiffies, alloc_start + stall_timeout)) {
> > > > + pr_warn("%s: page alloction stalls for %ums: order:%u mode:%#x(%pGg)\n",
> > > > + current->comm, jiffies_to_msecs(jiffies-alloc_start),
> > >
> > > Better if pid is also printed.
> >
> > I've tried to be consistent with warn_alloc_failed and that doesn't
> > print pid either. Maybe both of them should. Dunno
> >
> With pid imho we can distinguish two tasks with same name in a simpler way.

I've just checked dump_stack and dump_stack_print_info provides that
information already.
--
Michal Hocko
SUSE Labs