From: Michal Hocko <mhocko@kernel.org>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: "Jason Gunthorpe" <jgg@ziepe.ca>,
"Feng Tang" <feng.tang@intel.com>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Kees Cook" <keescook@chromium.org>,
"Masahiro Yamada" <yamada.masahiro@socionext.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
"Jann Horn" <jannh@google.com>,
LKML <linux-kernel@vger.kernel.org>,
"DRI Development" <dri-devel@lists.freedesktop.org>,
"Linux MM" <linux-mm@kvack.org>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"David Rientjes" <rientjes@google.com>,
"Wei Wang" <wvw@google.com>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Christian König" <christian.koenig@amd.com>
Subject: Re: [Intel-gfx] [PATCH 2/5] kernel.h: Add non_block_start/end()
Date: Fri, 16 Aug 2019 10:27:38 +0200 [thread overview]
Message-ID: <20190816082738.GC27790@dhcp22.suse.cz> (raw)
In-Reply-To: <CAKMK7uH42EgdxL18yce-7yay=x=Gb21nBs3nY7RA92Nsd-HCNA@mail.gmail.com>
On Thu 15-08-19 22:16:43, Daniel Vetter wrote:
> On Thu, Aug 15, 2019 at 9:35 PM Michal Hocko <mhocko@kernel.org> wrote:
[...]
> > > The last detail is I'm still unclear what a GFP flags a blockable
> > > invalidate_range_start() should use. Is GFP_KERNEL OK?
> >
> > I hope I will not make this muddy again ;)
> > invalidate_range_start in the blockable mode can use/depend on any sleepable
> > allocation allowed in the context it is called from. So in other words
> > it is no different from any other function in the kernel that calls into
> > allocator. As the API is missing gfp context then I hope it is not
> > called from any restricted contexts (except from the oom which we have
> > !blockable for).
>
> Hm, that's new to me. I thought mmu notifiers very much can be called
> from direct reclaim paths, so you have to be extremely careful with
> getting back into that one.
Correct, I should have added that notifier callbacks ideally do not
allocate any memory. They can block and even that is quite a pain to be
honest.
--
Michal Hocko
SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: "Jason Gunthorpe" <jgg@ziepe.ca>,
"Feng Tang" <feng.tang@intel.com>,
"Randy Dunlap" <rdunlap@infradead.org>,
"Kees Cook" <keescook@chromium.org>,
"Masahiro Yamada" <yamada.masahiro@socionext.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
"Jann Horn" <jannh@google.com>,
LKML <linux-kernel@vger.kernel.org>,
"DRI Development" <dri-devel@lists.freedesktop.org>,
"Linux MM" <linux-mm@kvack.org>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"David Rientjes" <rientjes@google.com>,
"Wei Wang" <wvw@google.com>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.co>
Subject: Re: [Intel-gfx] [PATCH 2/5] kernel.h: Add non_block_start/end()
Date: Fri, 16 Aug 2019 10:27:38 +0200 [thread overview]
Message-ID: <20190816082738.GC27790@dhcp22.suse.cz> (raw)
In-Reply-To: <CAKMK7uH42EgdxL18yce-7yay=x=Gb21nBs3nY7RA92Nsd-HCNA@mail.gmail.com>
On Thu 15-08-19 22:16:43, Daniel Vetter wrote:
> On Thu, Aug 15, 2019 at 9:35 PM Michal Hocko <mhocko@kernel.org> wrote:
[...]
> > > The last detail is I'm still unclear what a GFP flags a blockable
> > > invalidate_range_start() should use. Is GFP_KERNEL OK?
> >
> > I hope I will not make this muddy again ;)
> > invalidate_range_start in the blockable mode can use/depend on any sleepable
> > allocation allowed in the context it is called from. So in other words
> > it is no different from any other function in the kernel that calls into
> > allocator. As the API is missing gfp context then I hope it is not
> > called from any restricted contexts (except from the oom which we have
> > !blockable for).
>
> Hm, that's new to me. I thought mmu notifiers very much can be called
> from direct reclaim paths, so you have to be extremely careful with
> getting back into that one.
Correct, I should have added that notifier callbacks ideally do not
allocate any memory. They can block and even that is quite a pain to be
honest.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2019-08-16 8:27 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 20:20 [PATCH 0/5] hmm & mmu_notifier debug/lockdep annotations Daniel Vetter
2019-08-14 20:20 ` [PATCH 1/5] mm: Check if mmu notifier callbacks are allowed to fail Daniel Vetter
2019-08-14 22:14 ` Andrew Morton
2019-08-14 23:22 ` Jason Gunthorpe
2019-08-14 23:34 ` Ralph Campbell
2019-08-16 17:19 ` Jason Gunthorpe
2019-08-14 20:20 ` [PATCH 2/5] kernel.h: Add non_block_start/end() Daniel Vetter
2019-08-14 20:20 ` Daniel Vetter
2019-08-14 20:45 ` Andrew Morton
2019-08-14 20:45 ` Andrew Morton
2019-08-15 6:52 ` Daniel Vetter
2019-08-15 6:52 ` Daniel Vetter
2019-08-15 8:44 ` Michal Hocko
2019-08-15 8:44 ` Michal Hocko
2019-08-15 13:04 ` Jason Gunthorpe
2019-08-15 13:04 ` Jason Gunthorpe
2019-08-15 13:12 ` Daniel Vetter
2019-08-15 13:12 ` Daniel Vetter
2019-08-15 14:37 ` Jason Gunthorpe
2019-08-15 14:37 ` Jason Gunthorpe
2019-08-15 14:43 ` Daniel Vetter
2019-08-15 14:43 ` Daniel Vetter
2019-08-15 15:10 ` Jason Gunthorpe
2019-08-15 15:10 ` Jason Gunthorpe
2019-08-15 16:25 ` Daniel Vetter
2019-08-15 16:25 ` Daniel Vetter
2019-08-15 17:35 ` Jason Gunthorpe
2019-08-15 17:35 ` Jason Gunthorpe
2019-08-15 17:39 ` Jerome Glisse
2019-08-15 17:39 ` Jerome Glisse
2019-08-15 18:01 ` Jason Gunthorpe
2019-08-15 18:01 ` Jason Gunthorpe
2019-08-15 18:27 ` Jerome Glisse
2019-08-15 18:27 ` Jerome Glisse
2019-08-15 18:57 ` Jason Gunthorpe
2019-08-15 18:57 ` Jason Gunthorpe
2019-08-15 16:32 ` Jerome Glisse
2019-08-15 16:32 ` Jerome Glisse
2019-08-15 17:16 ` Jason Gunthorpe
2019-08-15 17:16 ` Jason Gunthorpe
2019-08-15 17:21 ` Daniel Vetter
2019-08-15 17:21 ` Daniel Vetter
2019-08-15 17:35 ` Jerome Glisse
2019-08-15 17:35 ` Jerome Glisse
2019-08-15 13:24 ` Michal Hocko
2019-08-15 13:24 ` Michal Hocko
2019-08-15 22:15 ` Andrew Morton
2019-08-15 22:15 ` Andrew Morton
2019-08-16 8:24 ` Michal Hocko
2019-08-16 8:24 ` Michal Hocko
2019-08-14 23:58 ` Jason Gunthorpe
2019-08-14 23:58 ` Jason Gunthorpe
2019-08-15 6:58 ` Daniel Vetter
2019-08-15 6:58 ` Daniel Vetter
2019-08-15 12:23 ` Jason Gunthorpe
2019-08-15 12:23 ` Jason Gunthorpe
2019-08-15 13:21 ` Michal Hocko
2019-08-15 13:21 ` Michal Hocko
2019-08-15 14:12 ` Jason Gunthorpe
2019-08-15 14:12 ` Jason Gunthorpe
2019-08-15 16:00 ` Michal Hocko
2019-08-15 16:00 ` Michal Hocko
2019-08-15 16:56 ` Jason Gunthorpe
2019-08-15 16:56 ` Jason Gunthorpe
2019-08-15 17:11 ` Jerome Glisse
2019-08-15 17:17 ` Jason Gunthorpe
2019-08-15 17:42 ` Michal Hocko
2019-08-15 17:42 ` Michal Hocko
2019-08-15 17:57 ` Jerome Glisse
2019-08-15 18:24 ` Jason Gunthorpe
2019-08-15 18:24 ` Jason Gunthorpe
2019-08-15 19:05 ` Michal Hocko
2019-08-15 19:05 ` Michal Hocko
2019-08-15 19:18 ` Jason Gunthorpe
2019-08-15 19:18 ` Jason Gunthorpe
2019-08-15 19:35 ` Michal Hocko
2019-08-15 19:35 ` Michal Hocko
2019-08-15 20:13 ` Jason Gunthorpe
2019-08-15 20:13 ` Jason Gunthorpe
2019-08-16 8:10 ` Michal Hocko
2019-08-16 8:10 ` Michal Hocko
2019-08-16 12:19 ` Jason Gunthorpe
2019-08-16 12:19 ` Jason Gunthorpe
2019-08-16 12:26 ` Michal Hocko
2019-08-16 12:26 ` Michal Hocko
2019-08-16 14:31 ` Jason Gunthorpe
2019-08-16 14:31 ` Jason Gunthorpe
2019-08-16 15:05 ` Jerome Glisse
2019-08-16 15:05 ` Jerome Glisse
2019-08-20 8:18 ` Michal Hocko
2019-08-20 8:18 ` Michal Hocko
2019-08-15 20:16 ` [Intel-gfx] " Daniel Vetter
2019-08-15 20:16 ` Daniel Vetter
2019-08-15 20:27 ` Jason Gunthorpe
2019-08-15 20:27 ` Jason Gunthorpe
2019-08-15 20:49 ` Daniel Vetter
2019-08-15 20:49 ` Daniel Vetter
2019-08-16 1:00 ` Jason Gunthorpe
2019-08-16 1:00 ` Jason Gunthorpe
2019-08-16 6:20 ` Daniel Vetter
2019-08-16 6:20 ` Daniel Vetter
2019-08-16 12:12 ` Jason Gunthorpe
2019-08-16 12:12 ` Jason Gunthorpe
2019-08-16 14:11 ` Daniel Vetter
2019-08-16 14:11 ` Daniel Vetter
2019-08-16 14:38 ` Jason Gunthorpe
2019-08-16 14:38 ` Jason Gunthorpe
2019-08-16 16:36 ` Daniel Vetter
2019-08-16 16:36 ` Daniel Vetter
2019-08-16 16:54 ` Jason Gunthorpe
2019-08-16 16:54 ` Jason Gunthorpe
2019-08-16 8:27 ` Michal Hocko [this message]
2019-08-16 8:27 ` Michal Hocko
2019-08-14 20:20 ` [PATCH 3/5] mm, notifier: Catch sleeping/blocking for !blockable Daniel Vetter
2019-08-15 0:00 ` Jason Gunthorpe
2019-08-15 7:02 ` Daniel Vetter
2019-08-15 12:35 ` Jason Gunthorpe
2019-08-17 16:09 ` Daniel Vetter
2019-08-17 16:09 ` Daniel Vetter
2019-08-14 20:20 ` [PATCH 4/5] mm, notifier: Add a lockdep map for invalidate_range_start Daniel Vetter
2019-08-15 0:09 ` Jason Gunthorpe
2019-08-15 7:10 ` Daniel Vetter
2019-08-15 7:10 ` Daniel Vetter
2019-08-15 12:53 ` Jason Gunthorpe
2019-08-14 20:20 ` [PATCH 5/5] mm/hmm: WARN on illegal ->sync_cpu_device_pagetables errors Daniel Vetter
2019-08-15 0:11 ` Jason Gunthorpe
2019-08-15 7:14 ` Daniel Vetter
2019-08-15 7:14 ` Daniel Vetter
2019-08-14 21:29 ` ✗ Fi.CI.CHECKPATCH: warning for hmm & mmu_notifier debug/lockdep annotations Patchwork
2019-08-14 21:56 ` ✓ Fi.CI.BAT: success " Patchwork
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