From: Daniel Vetter <daniel@ffwll.ch>
To: Alex Deucher <alexdeucher@gmail.com>
Cc: linux-rdma <linux-rdma@vger.kernel.org>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>,
"DRI Development" <dri-devel@lists.freedesktop.org>,
"Chris Wilson" <chris@chris-wilson.co.uk>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
"Thomas Hellström" <thomas.hellstrom@intel.com>,
"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
"Felix Kuehling" <Felix.Kuehling@amd.com>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Mika Kuoppala" <mika.kuoppala@intel.com>,
"Christian König" <christian.koenig@amd.com>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [Intel-gfx] [PATCH 01/25] dma-fence: basic lockdep annotations
Date: Tue, 14 Jul 2020 13:09:30 +0200 [thread overview]
Message-ID: <20200714110930.GD3278063@phenom.ffwll.local> (raw)
In-Reply-To: <CAKMK7uHbS8-jXDhGnKaK_65Hs4EUrcfBUe-wcvfPt18weCN0hQ@mail.gmail.com>
On Wed, Jul 08, 2020 at 05:37:19PM +0200, Daniel Vetter wrote:
> On Wed, Jul 8, 2020 at 5:19 PM Alex Deucher <alexdeucher@gmail.com> wrote:
> >
> > On Wed, Jul 8, 2020 at 11:13 AM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > >
> > > On Wed, Jul 8, 2020 at 4:57 PM Christian König <christian.koenig@amd.com> wrote:
> > > >
> > > > Could we merge this controlled by a separate config option?
> > > >
> > > > This way we could have the checks upstream without having to fix all the
> > > > stuff before we do this?
> > >
> > > Since it's fully opt-in annotations nothing blows up if we don't merge
> > > any annotations. So we could start merging the first 3 patches. After
> > > that the fun starts ...
> > >
> > > My rough idea was that first I'd try to tackle display, thus far
> > > there's 2 actual issues in drivers:
> > > - amdgpu has some dma_resv_lock in commit_tail, plus a kmalloc. I
> > > think those should be fairly easy to fix (I'd try a stab at them even)
> > > - vmwgfx has a full on locking inversion with dma_resv_lock in
> > > commit_tail, and that one is functional. Not just reading something
> > > which we can safely assume to be invariant anyway (like the tmz flag
> > > for amdgpu, or whatever it was).
> > >
> > > I've done a pile more annotations patches for other atomic drivers
> > > now, so hopefully that flushes out any remaining offenders here. Since
> > > some of the annotations are in helper code worst case we might need a
> > > dev->mode_config.broken_atomic_commit flag to disable them. At least
> > > for now I have 0 plans to merge any of these while there's known
> > > unsolved issues. Maybe if some drivers take forever to get fixed we
> > > can then apply some duct-tape for the atomic helper annotation patch.
> > > Instead of a flag we can also copypasta the atomic_commit_tail hook,
> > > leaving the annotations out and adding a huge warning about that.
> > >
> > > Next big chunk is the drm/scheduler annotations:
> > > - amdgpu needs a full rework of display reset (but apparently in the works)
> >
> > I think the display deadlock issues should be fixed in:
> > https://cgit.freedesktop.org/drm/drm/commit/?id=cdaae8371aa9d4ea1648a299b1a75946b9556944
Oh btw you have some more memory allocations in that commit, so you just
traded one deadlock for another one :-)
-Daniel
>
> That's the reset/tdr inversion, there's two more:
> - kmalloc, see https://cgit.freedesktop.org/~danvet/drm/commit/?id=d9353cc3bf6111430a24188b92412dc49e7ead79
> - ttm_bo_reserve in the wrong place
> https://cgit.freedesktop.org/~danvet/drm/commit/?id=a6c03176152625a2f9cf1e499aceb8b2217dc2a2
> - console_lock in the wrong spot
> https://cgit.freedesktop.org/~danvet/drm/commit/?id=a6c03176152625a2f9cf1e499aceb8b2217dc2a2
>
> Especially the last one I have no idea how to address really.
> -Daniel
>
>
> >
> > Alex
> >
> > > - I read all the drivers, they all have the fairly cosmetic issue of
> > > doing small allocations in their callbacks.
> > >
> > > I might end up typing the mempool we need for the latter issue, but
> > > first still hoping for some actual test feedback from other drivers
> > > using drm/scheduler. Again no intentions of merging these annotations
> > > without the drivers being fixed first, or at least some duct-atpe
> > > applied.
> > >
> > > Another option I've been thinking about, if there's cases where fixing
> > > things properly is a lot of effort: We could do annotations for broken
> > > sections (just the broken part, so we still catch bugs everywhere
> > > else). They'd simply drop&reacquire the lock. We could then e.g. use
> > > that in the amdgpu display reset code, and so still make sure that
> > > everything else in reset doesn't get worse. But I think adding that
> > > shouldn't be our first option.
> > >
> > > I'm not personally a big fan of the Kconfig or runtime option, only
> > > upsets people since it breaks lockdep for them. Or they ignore it, and
> > > we don't catch bugs, making it fairly pointless to merge.
> > >
> > > Cheers, Daniel
> > >
> > >
> > > >
> > > > Thanks,
> > > > Christian.
> > > >
> > > > Am 07.07.20 um 22:12 schrieb Daniel Vetter:
> > > > > Design is similar to the lockdep annotations for workers, but with
> > > > > some twists:
> > > > >
> > > > > - We use a read-lock for the execution/worker/completion side, so that
> > > > > this explicit annotation can be more liberally sprinkled around.
> > > > > With read locks lockdep isn't going to complain if the read-side
> > > > > isn't nested the same way under all circumstances, so ABBA deadlocks
> > > > > are ok. Which they are, since this is an annotation only.
> > > > >
> > > > > - We're using non-recursive lockdep read lock mode, since in recursive
> > > > > read lock mode lockdep does not catch read side hazards. And we
> > > > > _very_ much want read side hazards to be caught. For full details of
> > > > > this limitation see
> > > > >
> > > > > commit e91498589746065e3ae95d9a00b068e525eec34f
> > > > > Author: Peter Zijlstra <peterz@infradead.org>
> > > > > Date: Wed Aug 23 13:13:11 2017 +0200
> > > > >
> > > > > locking/lockdep/selftests: Add mixed read-write ABBA tests
> > > > >
> > > > > - To allow nesting of the read-side explicit annotations we explicitly
> > > > > keep track of the nesting. lock_is_held() allows us to do that.
> > > > >
> > > > > - The wait-side annotation is a write lock, and entirely done within
> > > > > dma_fence_wait() for everyone by default.
> > > > >
> > > > > - To be able to freely annotate helper functions I want to make it ok
> > > > > to call dma_fence_begin/end_signalling from soft/hardirq context.
> > > > > First attempt was using the hardirq locking context for the write
> > > > > side in lockdep, but this forces all normal spinlocks nested within
> > > > > dma_fence_begin/end_signalling to be spinlocks. That bollocks.
> > > > >
> > > > > The approach now is to simple check in_atomic(), and for these cases
> > > > > entirely rely on the might_sleep() check in dma_fence_wait(). That
> > > > > will catch any wrong nesting against spinlocks from soft/hardirq
> > > > > contexts.
> > > > >
> > > > > The idea here is that every code path that's critical for eventually
> > > > > signalling a dma_fence should be annotated with
> > > > > dma_fence_begin/end_signalling. The annotation ideally starts right
> > > > > after a dma_fence is published (added to a dma_resv, exposed as a
> > > > > sync_file fd, attached to a drm_syncobj fd, or anything else that
> > > > > makes the dma_fence visible to other kernel threads), up to and
> > > > > including the dma_fence_wait(). Examples are irq handlers, the
> > > > > scheduler rt threads, the tail of execbuf (after the corresponding
> > > > > fences are visible), any workers that end up signalling dma_fences and
> > > > > really anything else. Not annotated should be code paths that only
> > > > > complete fences opportunistically as the gpu progresses, like e.g.
> > > > > shrinker/eviction code.
> > > > >
> > > > > The main class of deadlocks this is supposed to catch are:
> > > > >
> > > > > Thread A:
> > > > >
> > > > > mutex_lock(A);
> > > > > mutex_unlock(A);
> > > > >
> > > > > dma_fence_signal();
> > > > >
> > > > > Thread B:
> > > > >
> > > > > mutex_lock(A);
> > > > > dma_fence_wait();
> > > > > mutex_unlock(A);
> > > > >
> > > > > Thread B is blocked on A signalling the fence, but A never gets around
> > > > > to that because it cannot acquire the lock A.
> > > > >
> > > > > Note that dma_fence_wait() is allowed to be nested within
> > > > > dma_fence_begin/end_signalling sections. To allow this to happen the
> > > > > read lock needs to be upgraded to a write lock, which means that any
> > > > > other lock is acquired between the dma_fence_begin_signalling() call and
> > > > > the call to dma_fence_wait(), and still held, this will result in an
> > > > > immediate lockdep complaint. The only other option would be to not
> > > > > annotate such calls, defeating the point. Therefore these annotations
> > > > > cannot be sprinkled over the code entirely mindless to avoid false
> > > > > positives.
> > > > >
> > > > > Originally I hope that the cross-release lockdep extensions would
> > > > > alleviate the need for explicit annotations:
> > > > >
> > > > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flwn.net%2FArticles%2F709849%2F&data=02%7C01%7Cchristian.koenig%40amd.com%7Cff1a9dd17c544534eeb808d822b21ba2%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637297495649621566&sdata=pbDwf%2BAG1UZ5bLZeep7VeGVQMnlQhX0TKG1d6Ok8GfQ%3D&reserved=0
> > > > >
> > > > > But there's a few reasons why that's not an option:
> > > > >
> > > > > - It's not happening in upstream, since it got reverted due to too
> > > > > many false positives:
> > > > >
> > > > > commit e966eaeeb623f09975ef362c2866fae6f86844f9
> > > > > Author: Ingo Molnar <mingo@kernel.org>
> > > > > Date: Tue Dec 12 12:31:16 2017 +0100
> > > > >
> > > > > locking/lockdep: Remove the cross-release locking checks
> > > > >
> > > > > This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y),
> > > > > while it found a number of old bugs initially, was also causing too many
> > > > > false positives that caused people to disable lockdep - which is arguably
> > > > > a worse overall outcome.
> > > > >
> > > > > - cross-release uses the complete() call to annotate the end of
> > > > > critical sections, for dma_fence that would be dma_fence_signal().
> > > > > But we do not want all dma_fence_signal() calls to be treated as
> > > > > critical, since many are opportunistic cleanup of gpu requests. If
> > > > > these get stuck there's still the main completion interrupt and
> > > > > workers who can unblock everyone. Automatically annotating all
> > > > > dma_fence_signal() calls would hence cause false positives.
> > > > >
> > > > > - cross-release had some educated guesses for when a critical section
> > > > > starts, like fresh syscall or fresh work callback. This would again
> > > > > cause false positives without explicit annotations, since for
> > > > > dma_fence the critical sections only starts when we publish a fence.
> > > > >
> > > > > - Furthermore there can be cases where a thread never does a
> > > > > dma_fence_signal, but is still critical for reaching completion of
> > > > > fences. One example would be a scheduler kthread which picks up jobs
> > > > > and pushes them into hardware, where the interrupt handler or
> > > > > another completion thread calls dma_fence_signal(). But if the
> > > > > scheduler thread hangs, then all the fences hang, hence we need to
> > > > > manually annotate it. cross-release aimed to solve this by chaining
> > > > > cross-release dependencies, but the dependency from scheduler thread
> > > > > to the completion interrupt handler goes through hw where
> > > > > cross-release code can't observe it.
> > > > >
> > > > > In short, without manual annotations and careful review of the start
> > > > > and end of critical sections, cross-relese dependency tracking doesn't
> > > > > work. We need explicit annotations.
> > > > >
> > > > > v2: handle soft/hardirq ctx better against write side and dont forget
> > > > > EXPORT_SYMBOL, drivers can't use this otherwise.
> > > > >
> > > > > v3: Kerneldoc.
> > > > >
> > > > > v4: Some spelling fixes from Mika
> > > > >
> > > > > v5: Amend commit message to explain in detail why cross-release isn't
> > > > > the solution.
> > > > >
> > > > > v6: Pull out misplaced .rst hunk.
> > > > >
> > > > > Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> > > > > Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
> > > > > Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > > > > Cc: Mika Kuoppala <mika.kuoppala@intel.com>
> > > > > Cc: Thomas Hellstrom <thomas.hellstrom@intel.com>
> > > > > Cc: linux-media@vger.kernel.org
> > > > > Cc: linaro-mm-sig@lists.linaro.org
> > > > > Cc: linux-rdma@vger.kernel.org
> > > > > Cc: amd-gfx@lists.freedesktop.org
> > > > > Cc: intel-gfx@lists.freedesktop.org
> > > > > Cc: Chris Wilson <chris@chris-wilson.co.uk>
> > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > > > > Cc: Christian König <christian.koenig@amd.com>
> > > > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > > > > ---
> > > > > Documentation/driver-api/dma-buf.rst | 6 +
> > > > > drivers/dma-buf/dma-fence.c | 161 +++++++++++++++++++++++++++
> > > > > include/linux/dma-fence.h | 12 ++
> > > > > 3 files changed, 179 insertions(+)
> > > > >
> > > > > diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
> > > > > index 7fb7b661febd..05d856131140 100644
> > > > > --- a/Documentation/driver-api/dma-buf.rst
> > > > > +++ b/Documentation/driver-api/dma-buf.rst
> > > > > @@ -133,6 +133,12 @@ DMA Fences
> > > > > .. kernel-doc:: drivers/dma-buf/dma-fence.c
> > > > > :doc: DMA fences overview
> > > > >
> > > > > +DMA Fence Signalling Annotations
> > > > > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > > > +
> > > > > +.. kernel-doc:: drivers/dma-buf/dma-fence.c
> > > > > + :doc: fence signalling annotation
> > > > > +
> > > > > DMA Fences Functions Reference
> > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > > >
> > > > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> > > > > index 656e9ac2d028..0005bc002529 100644
> > > > > --- a/drivers/dma-buf/dma-fence.c
> > > > > +++ b/drivers/dma-buf/dma-fence.c
> > > > > @@ -110,6 +110,160 @@ u64 dma_fence_context_alloc(unsigned num)
> > > > > }
> > > > > EXPORT_SYMBOL(dma_fence_context_alloc);
> > > > >
> > > > > +/**
> > > > > + * DOC: fence signalling annotation
> > > > > + *
> > > > > + * Proving correctness of all the kernel code around &dma_fence through code
> > > > > + * review and testing is tricky for a few reasons:
> > > > > + *
> > > > > + * * It is a cross-driver contract, and therefore all drivers must follow the
> > > > > + * same rules for lock nesting order, calling contexts for various functions
> > > > > + * and anything else significant for in-kernel interfaces. But it is also
> > > > > + * impossible to test all drivers in a single machine, hence brute-force N vs.
> > > > > + * N testing of all combinations is impossible. Even just limiting to the
> > > > > + * possible combinations is infeasible.
> > > > > + *
> > > > > + * * There is an enormous amount of driver code involved. For render drivers
> > > > > + * there's the tail of command submission, after fences are published,
> > > > > + * scheduler code, interrupt and workers to process job completion,
> > > > > + * and timeout, gpu reset and gpu hang recovery code. Plus for integration
> > > > > + * with core mm with have &mmu_notifier, respectively &mmu_interval_notifier,
> > > > > + * and &shrinker. For modesetting drivers there's the commit tail functions
> > > > > + * between when fences for an atomic modeset are published, and when the
> > > > > + * corresponding vblank completes, including any interrupt processing and
> > > > > + * related workers. Auditing all that code, across all drivers, is not
> > > > > + * feasible.
> > > > > + *
> > > > > + * * Due to how many other subsystems are involved and the locking hierarchies
> > > > > + * this pulls in there is extremely thin wiggle-room for driver-specific
> > > > > + * differences. &dma_fence interacts with almost all of the core memory
> > > > > + * handling through page fault handlers via &dma_resv, dma_resv_lock() and
> > > > > + * dma_resv_unlock(). On the other side it also interacts through all
> > > > > + * allocation sites through &mmu_notifier and &shrinker.
> > > > > + *
> > > > > + * Furthermore lockdep does not handle cross-release dependencies, which means
> > > > > + * any deadlocks between dma_fence_wait() and dma_fence_signal() can't be caught
> > > > > + * at runtime with some quick testing. The simplest example is one thread
> > > > > + * waiting on a &dma_fence while holding a lock::
> > > > > + *
> > > > > + * lock(A);
> > > > > + * dma_fence_wait(B);
> > > > > + * unlock(A);
> > > > > + *
> > > > > + * while the other thread is stuck trying to acquire the same lock, which
> > > > > + * prevents it from signalling the fence the previous thread is stuck waiting
> > > > > + * on::
> > > > > + *
> > > > > + * lock(A);
> > > > > + * unlock(A);
> > > > > + * dma_fence_signal(B);
> > > > > + *
> > > > > + * By manually annotating all code relevant to signalling a &dma_fence we can
> > > > > + * teach lockdep about these dependencies, which also helps with the validation
> > > > > + * headache since now lockdep can check all the rules for us::
> > > > > + *
> > > > > + * cookie = dma_fence_begin_signalling();
> > > > > + * lock(A);
> > > > > + * unlock(A);
> > > > > + * dma_fence_signal(B);
> > > > > + * dma_fence_end_signalling(cookie);
> > > > > + *
> > > > > + * For using dma_fence_begin_signalling() and dma_fence_end_signalling() to
> > > > > + * annotate critical sections the following rules need to be observed:
> > > > > + *
> > > > > + * * All code necessary to complete a &dma_fence must be annotated, from the
> > > > > + * point where a fence is accessible to other threads, to the point where
> > > > > + * dma_fence_signal() is called. Un-annotated code can contain deadlock issues,
> > > > > + * and due to the very strict rules and many corner cases it is infeasible to
> > > > > + * catch these just with review or normal stress testing.
> > > > > + *
> > > > > + * * &struct dma_resv deserves a special note, since the readers are only
> > > > > + * protected by rcu. This means the signalling critical section starts as soon
> > > > > + * as the new fences are installed, even before dma_resv_unlock() is called.
> > > > > + *
> > > > > + * * The only exception are fast paths and opportunistic signalling code, which
> > > > > + * calls dma_fence_signal() purely as an optimization, but is not required to
> > > > > + * guarantee completion of a &dma_fence. The usual example is a wait IOCTL
> > > > > + * which calls dma_fence_signal(), while the mandatory completion path goes
> > > > > + * through a hardware interrupt and possible job completion worker.
> > > > > + *
> > > > > + * * To aid composability of code, the annotations can be freely nested, as long
> > > > > + * as the overall locking hierarchy is consistent. The annotations also work
> > > > > + * both in interrupt and process context. Due to implementation details this
> > > > > + * requires that callers pass an opaque cookie from
> > > > > + * dma_fence_begin_signalling() to dma_fence_end_signalling().
> > > > > + *
> > > > > + * * Validation against the cross driver contract is implemented by priming
> > > > > + * lockdep with the relevant hierarchy at boot-up. This means even just
> > > > > + * testing with a single device is enough to validate a driver, at least as
> > > > > + * far as deadlocks with dma_fence_wait() against dma_fence_signal() are
> > > > > + * concerned.
> > > > > + */
> > > > > +#ifdef CONFIG_LOCKDEP
> > > > > +struct lockdep_map dma_fence_lockdep_map = {
> > > > > + .name = "dma_fence_map"
> > > > > +};
> > > > > +
> > > > > +/**
> > > > > + * dma_fence_begin_signalling - begin a critical DMA fence signalling section
> > > > > + *
> > > > > + * Drivers should use this to annotate the beginning of any code section
> > > > > + * required to eventually complete &dma_fence by calling dma_fence_signal().
> > > > > + *
> > > > > + * The end of these critical sections are annotated with
> > > > > + * dma_fence_end_signalling().
> > > > > + *
> > > > > + * Returns:
> > > > > + *
> > > > > + * Opaque cookie needed by the implementation, which needs to be passed to
> > > > > + * dma_fence_end_signalling().
> > > > > + */
> > > > > +bool dma_fence_begin_signalling(void)
> > > > > +{
> > > > > + /* explicitly nesting ... */
> > > > > + if (lock_is_held_type(&dma_fence_lockdep_map, 1))
> > > > > + return true;
> > > > > +
> > > > > + /* rely on might_sleep check for soft/hardirq locks */
> > > > > + if (in_atomic())
> > > > > + return true;
> > > > > +
> > > > > + /* ... and non-recursive readlock */
> > > > > + lock_acquire(&dma_fence_lockdep_map, 0, 0, 1, 1, NULL, _RET_IP_);
> > > > > +
> > > > > + return false;
> > > > > +}
> > > > > +EXPORT_SYMBOL(dma_fence_begin_signalling);
> > > > > +
> > > > > +/**
> > > > > + * dma_fence_end_signalling - end a critical DMA fence signalling section
> > > > > + *
> > > > > + * Closes a critical section annotation opened by dma_fence_begin_signalling().
> > > > > + */
> > > > > +void dma_fence_end_signalling(bool cookie)
> > > > > +{
> > > > > + if (cookie)
> > > > > + return;
> > > > > +
> > > > > + lock_release(&dma_fence_lockdep_map, _RET_IP_);
> > > > > +}
> > > > > +EXPORT_SYMBOL(dma_fence_end_signalling);
> > > > > +
> > > > > +void __dma_fence_might_wait(void)
> > > > > +{
> > > > > + bool tmp;
> > > > > +
> > > > > + tmp = lock_is_held_type(&dma_fence_lockdep_map, 1);
> > > > > + if (tmp)
> > > > > + lock_release(&dma_fence_lockdep_map, _THIS_IP_);
> > > > > + lock_map_acquire(&dma_fence_lockdep_map);
> > > > > + lock_map_release(&dma_fence_lockdep_map);
> > > > > + if (tmp)
> > > > > + lock_acquire(&dma_fence_lockdep_map, 0, 0, 1, 1, NULL, _THIS_IP_);
> > > > > +}
> > > > > +#endif
> > > > > +
> > > > > +
> > > > > /**
> > > > > * dma_fence_signal_locked - signal completion of a fence
> > > > > * @fence: the fence to signal
> > > > > @@ -170,14 +324,19 @@ int dma_fence_signal(struct dma_fence *fence)
> > > > > {
> > > > > unsigned long flags;
> > > > > int ret;
> > > > > + bool tmp;
> > > > >
> > > > > if (!fence)
> > > > > return -EINVAL;
> > > > >
> > > > > + tmp = dma_fence_begin_signalling();
> > > > > +
> > > > > spin_lock_irqsave(fence->lock, flags);
> > > > > ret = dma_fence_signal_locked(fence);
> > > > > spin_unlock_irqrestore(fence->lock, flags);
> > > > >
> > > > > + dma_fence_end_signalling(tmp);
> > > > > +
> > > > > return ret;
> > > > > }
> > > > > EXPORT_SYMBOL(dma_fence_signal);
> > > > > @@ -210,6 +369,8 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout)
> > > > >
> > > > > might_sleep();
> > > > >
> > > > > + __dma_fence_might_wait();
> > > > > +
> > > > > trace_dma_fence_wait_start(fence);
> > > > > if (fence->ops->wait)
> > > > > ret = fence->ops->wait(fence, intr, timeout);
> > > > > diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h
> > > > > index 3347c54f3a87..3f288f7db2ef 100644
> > > > > --- a/include/linux/dma-fence.h
> > > > > +++ b/include/linux/dma-fence.h
> > > > > @@ -357,6 +357,18 @@ dma_fence_get_rcu_safe(struct dma_fence __rcu **fencep)
> > > > > } while (1);
> > > > > }
> > > > >
> > > > > +#ifdef CONFIG_LOCKDEP
> > > > > +bool dma_fence_begin_signalling(void);
> > > > > +void dma_fence_end_signalling(bool cookie);
> > > > > +#else
> > > > > +static inline bool dma_fence_begin_signalling(void)
> > > > > +{
> > > > > + return true;
> > > > > +}
> > > > > +static inline void dma_fence_end_signalling(bool cookie) {}
> > > > > +static inline void __dma_fence_might_wait(void) {}
> > > > > +#endif
> > > > > +
> > > > > int dma_fence_signal(struct dma_fence *fence);
> > > > > int dma_fence_signal_locked(struct dma_fence *fence);
> > > > > signed long dma_fence_default_wait(struct dma_fence *fence,
> > > >
> > >
> > >
> > > --
> > > Daniel Vetter
> > > Software Engineer, Intel Corporation
> > > http://blog.ffwll.ch
> > > _______________________________________________
> > > amd-gfx mailing list
> > > amd-gfx@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>
>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2020-07-14 11:09 UTC|newest]
Thread overview: 134+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 20:12 [Intel-gfx] [PATCH 00/25] dma-fence annotations, round 3 Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 01/25] dma-fence: basic lockdep annotations Daniel Vetter
2020-07-08 14:57 ` Christian König
2020-07-08 15:12 ` Daniel Vetter
2020-07-08 15:19 ` Alex Deucher
2020-07-08 15:37 ` Daniel Vetter
2020-07-14 11:09 ` Daniel Vetter [this message]
2020-07-09 7:32 ` Daniel Stone
2020-07-09 7:52 ` Daniel Vetter
2020-07-13 16:26 ` Daniel Vetter
2020-07-13 16:39 ` Christian König
2020-07-13 20:31 ` Dave Airlie
2020-07-07 20:12 ` [Intel-gfx] [PATCH 02/25] dma-fence: prime " Daniel Vetter
2020-07-09 8:09 ` Daniel Vetter
2020-07-10 12:43 ` Jason Gunthorpe
2020-07-10 12:48 ` Christian König
2020-07-10 12:54 ` Jason Gunthorpe
2020-07-10 13:01 ` Christian König
2020-07-10 13:48 ` Jason Gunthorpe
2020-07-10 14:02 ` Daniel Vetter
2020-07-10 14:23 ` Jason Gunthorpe
2020-07-10 20:02 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 03/25] dma-buf.rst: Document why idenfinite fences are a bad idea Daniel Vetter
2020-07-09 7:36 ` Daniel Stone
2020-07-09 8:04 ` Daniel Vetter
2020-07-09 12:11 ` Daniel Stone
2020-07-09 12:31 ` Daniel Vetter
2020-07-09 14:28 ` Christian König
2020-07-09 11:53 ` Christian König
2020-07-09 12:33 ` [Intel-gfx] [PATCH 1/2] dma-buf.rst: Document why indefinite " Daniel Vetter
2020-07-09 12:33 ` [Intel-gfx] [PATCH 2/2] drm/virtio: Remove open-coded commit-tail function Daniel Vetter
2020-07-09 12:48 ` Gerd Hoffmann
2020-07-09 14:05 ` Sam Ravnborg
2020-07-14 9:13 ` Daniel Vetter
2020-08-19 12:43 ` Jiri Slaby
2020-08-19 12:47 ` Jiri Slaby
2020-08-19 13:24 ` Gerd Hoffmann
2020-08-20 6:32 ` Jiri Slaby
2020-08-21 7:01 ` Gerd Hoffmann
2020-07-10 12:30 ` [Intel-gfx] [PATCH 1/2] dma-buf.rst: Document why indefinite fences are a bad idea Maarten Lankhorst
2020-07-14 17:46 ` Jason Ekstrand
2020-07-20 11:15 ` [Intel-gfx] [Linaro-mm-sig] " Thomas Hellström (Intel)
2020-07-21 7:41 ` Daniel Vetter
2020-07-21 7:45 ` Christian König
2020-07-21 8:47 ` Thomas Hellström (Intel)
2020-07-21 8:55 ` Christian König
2020-07-21 9:16 ` Daniel Vetter
2020-07-21 9:24 ` Daniel Vetter
2020-07-21 9:37 ` Thomas Hellström (Intel)
2020-07-21 9:50 ` Daniel Vetter
2020-07-21 10:47 ` Thomas Hellström (Intel)
2020-07-21 13:59 ` Christian König
2020-07-21 17:46 ` Thomas Hellström (Intel)
2020-07-21 18:18 ` Daniel Vetter
2020-07-21 21:42 ` Dave Airlie
2020-07-21 22:45 ` Dave Airlie
2020-07-22 6:45 ` Thomas Hellström (Intel)
2020-07-22 7:11 ` Daniel Vetter
2020-07-22 8:05 ` Thomas Hellström (Intel)
2020-07-22 9:45 ` Daniel Vetter
2020-07-22 10:31 ` Thomas Hellström (Intel)
2020-07-22 11:39 ` Daniel Vetter
2020-07-22 12:22 ` Thomas Hellström (Intel)
2020-07-22 12:41 ` Daniel Vetter
2020-07-22 13:12 ` Thomas Hellström (Intel)
2020-07-22 14:07 ` Daniel Vetter
2020-07-22 14:23 ` Christian König
2020-07-22 14:30 ` Thomas Hellström (Intel)
2020-07-22 14:35 ` Christian König
2020-07-07 20:12 ` [Intel-gfx] [PATCH 04/25] drm/vkms: Annotate vblank timer Daniel Vetter
2020-07-12 22:27 ` Rodrigo Siqueira
2020-07-14 9:57 ` Melissa Wen
2020-07-14 9:59 ` Daniel Vetter
2020-07-14 14:55 ` Melissa Wen
2020-07-14 15:23 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 05/25] drm/vblank: Annotate with dma-fence signalling section Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 06/25] drm/amdgpu: add dma-fence annotations to atomic commit path Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 07/25] drm/komdea: Annotate dma-fence critical section in " Daniel Vetter
2020-07-08 5:17 ` james qian wang (Arm Technology China)
2020-07-14 8:34 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 08/25] drm/malidp: " Daniel Vetter
2020-07-15 12:53 ` Liviu Dudau
2020-07-15 13:51 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 09/25] drm/atmel: Use drm_atomic_helper_commit Daniel Vetter
2020-07-07 20:37 ` Sam Ravnborg
2020-07-07 21:31 ` [Intel-gfx] [PATCH] " Daniel Vetter
2020-07-14 9:55 ` Sam Ravnborg
2020-07-07 20:12 ` [Intel-gfx] [PATCH 10/25] drm/imx: Annotate dma-fence critical section in commit path Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 11/25] drm/omapdrm: " Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 12/25] drm/rcar-du: " Daniel Vetter
2020-07-07 23:32 ` Laurent Pinchart
2020-07-14 8:39 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 13/25] drm/tegra: " Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 14/25] drm/tidss: " Daniel Vetter
2020-07-08 9:01 ` Jyri Sarha
2020-07-07 20:12 ` [Intel-gfx] [PATCH 15/25] drm/tilcdc: Use standard drm_atomic_helper_commit Daniel Vetter
2020-07-08 9:17 ` Jyri Sarha
2020-07-08 9:27 ` Daniel Vetter
2020-07-08 9:44 ` [Intel-gfx] [PATCH] " Daniel Vetter
2020-07-08 10:21 ` Jyri Sarha
2020-07-08 14:20 ` Daniel Vetter
2020-07-10 11:16 ` Jyri Sarha
2020-07-14 8:32 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 16/25] drm/atomic-helper: Add dma-fence annotations Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 17/25] drm/scheduler: use dma-fence annotations in main thread Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 18/25] drm/amdgpu: use dma-fence annotations in cs_submit() Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 19/25] drm/amdgpu: s/GFP_KERNEL/GFP_ATOMIC in scheduler code Daniel Vetter
2020-07-14 10:49 ` Daniel Vetter
2020-07-14 11:40 ` Christian König
2020-07-14 14:31 ` Daniel Vetter
2020-07-15 9:17 ` Christian König
2020-07-15 11:53 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 20/25] drm/amdgpu: DC also loves to allocate stuff where it shouldn't Daniel Vetter
2020-07-14 11:12 ` Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 21/25] drm/amdgpu/dc: Stop dma_resv_lock inversion in commit_tail Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 22/25] drm/scheduler: use dma-fence annotations in tdr work Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 23/25] drm/amdgpu: use dma-fence annotations for gpu reset code Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 24/25] Revert "drm/amdgpu: add fbdev suspend/resume on gpu reset" Daniel Vetter
2020-07-07 20:12 ` [Intel-gfx] [PATCH 25/25] drm/amdgpu: gpu recovery does full modesets Daniel Vetter
2020-07-07 22:10 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for dma-fence annotations, round 3 (rev2) Patchwork
2020-07-07 22:12 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2020-07-07 22:32 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-07-08 0:59 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
2020-07-08 11:13 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for dma-fence annotations, round 3 (rev3) Patchwork
2020-07-08 11:14 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2020-07-08 11:37 ` [Intel-gfx] ✗ Fi.CI.BAT: failure " Patchwork
2020-07-08 14:53 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for dma-fence annotations, round 3 (rev4) Patchwork
2020-07-08 14:55 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2020-07-08 15:15 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-07-08 18:46 ` [Intel-gfx] ✗ Fi.CI.IGT: failure " Patchwork
2020-07-09 13:05 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for dma-fence annotations, round 3 (rev6) Patchwork
2020-07-09 13:06 ` [Intel-gfx] ✗ Fi.CI.SPARSE: " Patchwork
2020-07-09 13:26 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2020-07-09 15:38 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
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