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authorChristian Brauner <brauner@kernel.org>2025-06-12 15:25:24 +0200
committerChristian Brauner <brauner@kernel.org>2025-06-16 17:01:22 +0200
commit7bbb05dbea38e56d9f6ac7ac1040f93b0808cbce (patch)
tree7c1e4eab6e3266cdf33cf5a9e1132ede1f454ae0 /tools/perf/scripts/python/bin/stackcollapse-record
parent70e3ee31282d293c794fb5bbec8efe495c32044b (diff)
downloadkernel-7bbb05dbea38e56d9f6ac7ac1040f93b0808cbce.tar.gz
coredump: split file coredumping into coredump_file()
* Move that whole mess into a separate helper instead of having all that hanging around in vfs_coredump() directly. * Stop using that need_suid_safe variable and add an inline helper that clearly communicates what's going on everywhere consistently. The mm flag snapshot is stable and can't change so nothing's gained with that boolean. * Only setup cprm->file once everything else succeeded, using RAII for the coredump file before. That allows to don't care to what goto label we jump in vfs_coredump(). Link: https://lore.kernel.org/20250612-work-coredump-massage-v1-10-315c0c34ba94@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'tools/perf/scripts/python/bin/stackcollapse-record')
0 files changed, 0 insertions, 0 deletions
e item to the shrinker, we cannot precisely control the number of shrinker objects we scan on each pass; and indeed may free more than requested. If we fail to tell the shrinker about the number of objects we process, it will continue to hold a grudge against us as any objects left unscanned are added to the next reclaim -- and so we will keep on "unfairly" shrinking our own slab in comparison to other slabs. v2: fixup the misplaced addition, we want to count everything we scan (to match the number we reported earlier) not just the objects we successfully validated and freed. References: 912d572d63b8 ("drm/i915: wire up shrinkctl->nr_scanned") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171013202621.7276-6-chris@chris-wilson.co.uk 2017-10-16drm/i915: Move dev_priv->mm.[un]bound_list to its own lockChris Wilson Remove the struct_mutex requirement around dev_priv->mm.bound_list and dev_priv->mm.unbound_list by giving it its own spinlock. This reduces one more requirement for struct_mutex and in the process gives us slightly more accurate unbound_list tracking, which should improve the shrinker - but the drawback is that we drop the retirement before counting so i915_gem_object_is_active() may be stale and lead us to underestimate the number of objects that may be shrunk (see commit bed50aea61df ("drm/i915/shrinker: Flush active on objects before counting")). v2: Crosslink the spinlock to the lists it protects, and btw this changes s/obj->global_link/obj->mm.link/ v3: Fix decoupling of old links in i915_gem_object_attach_phys() v3.1: Fix the fix, only unlink if it was linked v3.2: Use a local for to_i915(obj->base.dev)->mm.obj_lock Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171016114037.5556-1-chris@chris-wilson.co.uk 2017-10-16drm/i915: Remove walk over obj->vma_list for the shrinkerChris Wilson In the next patch, we want to reduce the lock coverage within the shrinker, and one of the dangerous walks we have is over obj->vma_list. We are only walking the obj->vma_list in order to check whether it has been permanently pinned by HW access, typically via use on the scanout. But we have a couple of other long term pins, the context objects for which we currently have to check the individual vma pin_count. If we instead mark these using obj->pin_display, we can forgo the dangerous and sometimes slow list iteration. v2: Rearrange code to try and avoid confusion from false associations due to arrangement of whitespace along with rebasing on obj->pin_global. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171013202621.7276-4-chris@chris-wilson.co.uk 2017-10-16drm/i915: Refactor testing obj->mm.pagesChris Wilson Since we occasionally stuff an error pointer into obj->mm.pages for a semi-permanent or even permanent failure, we have to be more careful and not just test against NULL when deciding if the object has a complete set of its concurrent pages. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171013202621.7276-1-chris@chris-wilson.co.uk 2017-09-06drm/i915: wire up shrinkctl->nr_scannedChris Wilson shrink_slab() allows us to report back the number of objects we successfully scanned (out of the target shrinkctl->nr_to_scan). As report the number of pages owned by each GEM object as a separate item to the shrinker, we cannot precisely control the number of shrinker objects we scan on each pass; and indeed may free more than requested. If we fail to tell the shrinker about the number of objects we process, it will continue to hold a grudge against us as any objects left unscanned are added to the next reclaim -- and so we will keep on "unfairly" shrinking our own slab in comparison to other slabs. Link: http://lkml.kernel.org/r/20170822135325.9191-2-chris@chris-wilson.co.uk Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Shaohua Li <shli@fb.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2017-08-07drm/i915/shrinker: Wrap need_resched() inside preempt-disableChris Wilson In order for us to successfully detect the end of a timeslice, preemption must be disabled. Otherwise, inside the loop we may be preempted many times without our noticing, and each time our timeslice will be reset, invalidating need_resched() Reported-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reported-by: Tomi Sarvela <tomi.p.sarvela@intel.com> Fixes: 290271de34f6 ("drm/i915: Spin for struct_mutex inside shrinker") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.13-rc1+ Link: https://patchwork.freedesktop.org/patch/msgid/20170804104135.26805-1-chris@chris-wilson.co.uk Tested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (cherry picked from commit 6cb0c6ad9e07f2c7971c4e8e0d9b7ceba151a925) Signed-off-by: Jani Nikula <jani.nikula@intel.com> 2017-06-14drm/i915: Spin for struct_mutex inside shrinkerChris Wilson Having resolved whether or not we would deadlock upon a call to mutex_lock(&dev->struct_mutex), we can then spin for the contended struct_mutex if we are not the owner. We cannot afford to simply block and wait for the mutex, as the owner may itself be waiting for the allocator -- i.e. a cyclic deadlock. This should significantly improve the chance of running the shrinker for other processes whilst the GPU is busy. A more balanced approach would be to optimistically spin whilst the mutex owner was on the cpu and there was an opportunity to acquire the mutex for ourselves quickly. However, that requires support from kernel/locking/ and a new mutex_spin_trylock() primitive. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170609110350.1767-4-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> 2017-06-02drm/i915: Allow kswapd to pause the device whilst reapingChris Wilson In commit 5763ff04dc4e ("drm/i915: Avoid GPU stalls from kswapd") we stopped direct reclaim and kswapd from triggering GPU/client stalls whilst running (by restricting the objects they could reap to be idle). However with abusive GPU usage, it becomes quite easy to starve kswapd of memory and prevent it from making forward progress towards obtaining enough free memory (thus driving the system closer to swap exhaustion). Relax the previous restriction to allow kswapd (but not direct reclaim) to stall the device whilst reaping purgeable pages. v2: Also acquire the rpm wakelock to allow kswapd to unbind buffers. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170601133331.5973-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> 2017-05-25drm/i915: Only GGTT vma may be pinned and prevent shrinkingChris Wilson As only GGTT vma may be permanently pinned and are always at the head of the object's vma list, as soon as we seen a ppGTT vma we can stop searching for any_vma_pinned(). Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170525072528.11185-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> 2017-05-11drm/i915: Do not sync RCU during shrinkingJoonas Lahtinen Due to the complex dependencies between workqueues and RCU, which are not easily detected by lockdep, do not synchronize RCU during shrinking. On low-on-memory systems (mem=1G for example), the RCU sync leads to all system workqueus freezing and unrelated lockdep splats are displayed according to reports. GIT bisecting done by J. R. Okajima points to the commit where RCU syncing was extended. RCU sync gains us very little benefit in real life scenarios where the amount of memory used by object backing storage is dominant over the metadata under RCU, so drop it altogether. " Yeeeaah, if core could just, go ahead and reclaim RCU queues, that'd be great. " - Chris Wilson, 2016 (0eafec6d3244) v2: More information to commit message. v3: Remove "grep _rcu_" escapee from i915_gem_shrink_all (Andrea) Fixes: c053b5a506d3 ("drm/i915: Don't call synchronize_rcu_expedited under struct_mutex") Suggested-by: Chris Wilson <chris@chris-wilson.co.uk> Reported-by: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Hugh Dickins <hughd@google.com> Tested-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: J. R. Okajima <hooanon05g@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: <stable@vger.kernel.org> # v4.11+ Link: http://patchwork.freedesktop.org/patch/msgid/1494414040-11160-1-git-send-email-joonas.lahtinen@linux.intel.com 2017-04-07drm/i915: Simplify shrinker lockingJoonas Lahtinen By using the same structure for both interruptible and uninterruptible locking in shrinker code, combined with the information that mm.interruptible is only being written to, the code can be greatly simplified. Also removing the i915_gem_ prefix from the locking functions so that nobody in their wildest dreams considers exporting them. Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/1491562175-27680-1-git-send-email-joonas.lahtinen@linux.intel.com 2017-04-07drm/i915: Don't call synchronize_rcu_expedited under struct_mutexJoonas Lahtinen Only call synchronize_rcu_expedited after unlocking struct_mutex to avoid deadlock because the workqueues depend on struct_mutex. >From original patch by Andrea: synchronize_rcu/synchronize_sched/synchronize_rcu_expedited() will hang until its own workqueues are run. The i915 gem workqueues will wait on the struct_mutex to be released. So we cannot wait for a quiescent state using those rcu primitives while holding the struct_mutex or it creates a circular lock dependency resulting in kernel hangs (which is reproducible but goes undetected by lockdep). kswapd0 D 0 700 2 0x00000000 Call Trace: ? __schedule+0x1a5/0x660 ? schedule+0x36/0x80 ? _synchronize_rcu_expedited.constprop.65+0x2ef/0x300 ? wake_up_bit+0x20/0x20 ? rcu_stall_kick_kthreads.part.54+0xc0/0xc0 ? rcu_exp_wait_wake+0x530/0x530 ? i915_gem_shrink+0x34b/0x4b0 ? i915_gem_shrinker_scan+0x7c/0x90 ? i915_gem_shrinker_scan+0x7c/0x90 ? shrink_slab.part.61.constprop.72+0x1c1/0x3a0 ? shrink_zone+0x154/0x160 ? kswapd+0x40a/0x720 ? kthread+0xf4/0x130 ? try_to_free_pages+0x450/0x450 ? kthread_create_on_node+0x40/0x40 ? ret_from_fork+0x23/0x30 plasmashell D 0 4657 4614 0x00000000 Call Trace: ? __schedule+0x1a5/0x660 ? schedule+0x36/0x80 ? schedule_preempt_disabled+0xe/0x10 ? __mutex_lock.isra.4+0x1c9/0x790 ? i915_gem_close_object+0x26/0xc0 ? i915_gem_close_object+0x26/0xc0 ? drm_gem_object_release_handle+0x48/0x90 ? drm_gem_handle_delete+0x50/0x80 ? drm_ioctl+0x1fa/0x420 ? drm_gem_handle_create+0x40/0x40 ? pipe_write+0x391/0x410 ? __vfs_write+0xc6/0x120 ? do_vfs_ioctl+0x8b/0x5d0 ? SyS_ioctl+0x3b/0x70 ? entry_SYSCALL_64_fastpath+0x13/0x94 kworker/0:0 D 0 29186 2 0x00000000 Workqueue: events __i915_gem_free_work Call Trace: ? __schedule+0x1a5/0x660 ? schedule+0x36/0x80 ? schedule_preempt_disabled+0xe/0x10 ? __mutex_lock.isra.4+0x1c9/0x790 ? del_timer_sync+0x44/0x50 ? update_curr+0x57/0x110 ? __i915_gem_free_objects+0x31/0x300 ? __i915_gem_free_objects+0x31/0x300 ? __i915_gem_free_work+0x2d/0x40 ? process_one_work+0x13a/0x3b0 ? worker_thread+0x4a/0x460 ? kthread+0xf4/0x130 ? process_one_work+0x3b0/0x3b0 ? kthread_create_on_node+0x40/0x40 ? ret_from_fork+0x23/0x30 Fixes: 3d3d18f086cd ("drm/i915: Avoid rcu_barrier() from reclaim paths (shrinker)") Reported-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> 2017-03-14drm/i915: Avoid rcu_barrier() from reclaim paths (shrinker)Chris Wilson The rcu_barrier() takes the cpu_hotplug mutex which itself is not reclaim-safe, and so rcu_barrier() is illegal from inside the shrinker. [ 309.661373] ========================================================= [ 309.661376] [ INFO: possible irq lock inversion dependency detected ] [ 309.661380] 4.11.0-rc1-CI-CI_DRM_2333+ #1 Tainted: G W [ 309.661383] --------------------------------------------------------- [ 309.661386] gem_exec_gttfil/6435 just changed the state of lock: [ 309.661389] (rcu_preempt_state.barrier_mutex){+.+.-.}, at: [<ffffffff81100731>] _rcu_barrier+0x31/0x160 [ 309.661399] but this lock took another, RECLAIM_FS-unsafe lock in the past: [ 309.661402] (cpu_hotplug.lock){+.+.+.} [ 309.661404] and interrupts could create inverse lock ordering between them. [ 309.661410] other info that might help us debug this: [ 309.661414] Possible interrupt unsafe locking scenario: [ 309.661417] CPU0 CPU1 [ 309.661419] ---- ---- [ 309.661421] lock(cpu_hotplug.lock); [ 309.661425] local_irq_disable(); [ 309.661432] lock(rcu_preempt_state.barrier_mutex); [ 309.661441] lock(cpu_hotplug.lock); [ 309.661446] <Interrupt> [ 309.661448] lock(rcu_preempt_state.barrier_mutex); [ 309.661453] *** DEADLOCK *** [ 309.661460] 4 locks held by gem_exec_gttfil/6435: [ 309.661464] #0: (sb_writers#10){.+.+.+}, at: [<ffffffff8120d83d>] vfs_write+0x17d/0x1f0 [ 309.661475] #1: (debugfs_srcu){......}, at: [<ffffffff81320491>] debugfs_use_file_start+0x41/0xa0 [ 309.661486] #2: (&attr->mutex){+.+.+.}, at: [<ffffffff8123a3e7>] simple_attr_write+0x37/0xe0 [ 309.661495] #3: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0091b4a>] i915_drop_caches_set+0x3a/0x150 [i915] [ 309.661540] the shortest dependencies between 2nd lock and 1st lock: [ 309.661547] -> (cpu_hotplug.lock){+.+.+.} ops: 829 { [ 309.661553] HARDIRQ-ON-W at: [ 309.661560] __lock_acquire+0x5e5/0x1b50 [ 309.661565] lock_acquire+0xc9/0x220 [ 309.661572] __mutex_lock+0x6e/0x990 [ 309.661576] mutex_lock_nested+0x16/0x20 [ 309.661583] get_online_cpus+0x61/0x80 [ 309.661590] kmem_cache_create+0x25/0x1d0 [ 309.661596] debug_objects_mem_init+0x30/0x249 [ 309.661602] start_kernel+0x341/0x3fe [ 309.661607] x86_64_start_reservations+0x2a/0x2c [ 309.661612] x86_64_start_kernel+0x173/0x186 [ 309.661619] verify_cpu+0x0/0xfc [ 309.661622] SOFTIRQ-ON-W at: [ 309.661627] __lock_acquire+0x611/0x1b50 [ 309.661632] lock_acquire+0xc9/0x220 [ 309.661636] __mutex_lock+0x6e/0x990 [ 309.661641] mutex_lock_nested+0x16/0x20 [ 309.661646] get_online_cpus+0x61/0x80 [ 309.661650] kmem_cache_create+0x25/0x1d0 [ 309.661655] debug_objects_mem_init+0x30/0x249 [ 309.661660] start_kernel+0x341/0x3fe [ 309.661664] x86_64_start_reservations+0x2a/0x2c [ 309.661669] x86_64_start_kernel+0x173/0x186 [ 309.661674] verify_cpu+0x0/0xfc [ 309.661677] RECLAIM_FS-ON-W at: [ 309.661682] mark_held_locks+0x6f/0xa0 [ 309.661687] lockdep_trace_alloc+0xb3/0x100 [ 309.661693] kmem_cache_alloc_trace+0x31/0x2e0 [ 309.661699] __smpboot_create_thread.part.1+0x27/0xe0 [ 309.661704] smpboot_create_threads+0x61/0x90 [ 309.661709] cpuhp_invoke_callback+0x9c/0x8a0 [ 309.661713] cpuhp_up_callbacks+0x31/0xb0 [ 309.661718] _cpu_up+0x7a/0xc0 [ 309.661723] do_cpu_up+0x5f/0x80 [ 309.661727] cpu_up+0xe/0x10 [ 309.661734] smp_init+0x71/0xb3 [ 309.661738] kernel_init_freeable+0x94/0x19e [ 309.661743] kernel_init+0x9/0xf0 [ 309.661748] ret_from_fork+0x2e/0x40 [ 309.661752] INITIAL USE at: [ 309.661757] __lock_acquire+0x234/0x1b50 [ 309.661761] lock_acquire+0xc9/0x220 [ 309.661766] __mutex_lock+0x6e/0x990 [ 309.661771] mutex_lock_nested+0x16/0x20 [ 309.661775] get_online_cpus+0x61/0x80 [ 309.661780] __cpuhp_setup_state+0x44/0x170 [ 309.661785] page_alloc_init+0x23/0x3a [ 309.661790] start_kernel+0x124/0x3fe [ 309.661794] x86_64_start_reservations+0x2a/0x2c [ 309.661799] x86_64_start_kernel+0x173/0x186 [ 309.661804] verify_cpu+0x0/0xfc [ 309.661807] } [ 309.661813] ... key at: [<ffffffff81e37690>] cpu_hotplug+0xb0/0x100 [ 309.661817] ... acquired at: [ 309.661821] lock_acquire+0xc9/0x220 [ 309.661825] __mutex_lock+0x6e/0x990 [ 309.661829] mutex_lock_nested+0x16/0x20 [ 309.661833] get_online_cpus+0x61/0x80 [ 309.661837] _rcu_barrier+0x9f/0x160 [ 309.661841] rcu_barrier+0x10/0x20 [ 309.661847] netdev_run_todo+0x5f/0x310 [ 309.661852] rtnl_unlock+0x9/0x10 [ 309.661856] default_device_exit_batch+0x133/0x150 [ 309.661862] ops_exit_list.isra.0+0x4d/0x60 [ 309.661866] cleanup_net+0x1d8/0x2c0 [ 309.661872] process_one_work+0x1f4/0x6d0 [ 309.661876] worker_thread+0x49/0x4a0 [ 309.661881] kthread+0x107/0x140 [ 309.661884] ret_from_fork+0x2e/0x40 [ 309.661890] -> (rcu_preempt_state.barrier_mutex){+.+.-.} ops: 179 { [ 309.661896] HARDIRQ-ON-W at: [ 309.661901] __lock_acquire+0x5e5/0x1b50 [ 309.661905] lock_acquire+0xc9/0x220 [ 309.661910] __mutex_lock+0x6e/0x990 [ 309.661914] mutex_lock_nested+0x16/0x20 [ 309.661919] _rcu_barrier+0x31/0x160 [ 309.661923] rcu_barrier+0x10/0x20 [ 309.661928] netdev_run_todo+0x5f/0x310 [ 309.661932] rtnl_unlock+0x9/0x10 [ 309.661936] default_device_exit_batch+0x133/0x150 [ 309.661941] ops_exit_list.isra.0+0x4d/0x60 [ 309.661946] cleanup_net+0x1d8/0x2c0 [ 309.661951] process_one_work+0x1f4/0x6d0 [ 309.661955] worker_thread+0x49/0x4a0 [ 309.661960] kthread+0x107/0x140 [ 309.661964] ret_from_fork+0x2e/0x40 [ 309.661968] SOFTIRQ-ON-W at: [ 309.661972] __lock_acquire+0x611/0x1b50 [ 309.661977] lock_acquire+0xc9/0x220 [ 309.661981] __mutex_lock+0x6e/0x990 [ 309.661986] mutex_lock_nested+0x16/0x20 [ 309.661990] _rcu_barrier+0x31/0x160 [ 309.661995] rcu_barrier+0x10/0x20 [ 309.661999] netdev_run_todo+0x5f/0x310 [ 309.662003] rtnl_unlock+0x9/0x10 [ 309.662008] default_device_exit_batch+0x133/0x150 [ 309.662013] ops_exit_list.isra.0+0x4d/0x60 [ 309.662017] cleanup_net+0x1d8/0x2c0 [ 309.662022] process_one_work+0x1f4/0x6d0 [ 309.662027] worker_thread+0x49/0x4a0 [ 309.662031] kthread+0x107/0x140 [ 309.662035] ret_from_fork+0x2e/0x40 [ 309.662039] IN-RECLAIM_FS-W at: [ 309.662043] __lock_acquire+0x638/0x1b50 [ 309.662048] lock_acquire+0xc9/0x220 [ 309.662053] __mutex_lock+0x6e/0x990 [ 309.662058] mutex_lock_nested+0x16/0x20 [ 309.662062] _rcu_barrier+0x31/0x160 [ 309.662067] rcu_barrier+0x10/0x20 [ 309.662089] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662109] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662114] simple_attr_write+0xc7/0xe0 [ 309.662119] full_proxy_write+0x4f/0x70 [ 309.662124] __vfs_write+0x23/0x120 [ 309.662128] vfs_write+0xc6/0x1f0 [ 309.662133] SyS_write+0x44/0xb0 [ 309.662138] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662142] INITIAL USE at: [ 309.662147] __lock_acquire+0x234/0x1b50 [ 309.662151] lock_acquire+0xc9/0x220 [ 309.662156] __mutex_lock+0x6e/0x990 [ 309.662160] mutex_lock_nested+0x16/0x20 [ 309.662165] _rcu_barrier+0x31/0x160 [ 309.662169] rcu_barrier+0x10/0x20 [ 309.662174] netdev_run_todo+0x5f/0x310 [ 309.662178] rtnl_unlock+0x9/0x10 [ 309.662183] default_device_exit_batch+0x133/0x150 [ 309.662188] ops_exit_list.isra.0+0x4d/0x60 [ 309.662192] cleanup_net+0x1d8/0x2c0 [ 309.662197] process_one_work+0x1f4/0x6d0 [ 309.662202] worker_thread+0x49/0x4a0 [ 309.662206] kthread+0x107/0x140 [ 309.662210] ret_from_fork+0x2e/0x40 [ 309.662214] } [ 309.662220] ... key at: [<ffffffff81e4e1c8>] rcu_preempt_state+0x508/0x780 [ 309.662225] ... acquired at: [ 309.662229] check_usage_forwards+0x12b/0x130 [ 309.662233] mark_lock+0x360/0x6f0 [ 309.662237] __lock_acquire+0x638/0x1b50 [ 309.662241] lock_acquire+0xc9/0x220 [ 309.662245] __mutex_lock+0x6e/0x990 [ 309.662249] mutex_lock_nested+0x16/0x20 [ 309.662253] _rcu_barrier+0x31/0x160 [ 309.662257] rcu_barrier+0x10/0x20 [ 309.662279] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662298] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662303] simple_attr_write+0xc7/0xe0 [ 309.662307] full_proxy_write+0x4f/0x70 [ 309.662311] __vfs_write+0x23/0x120 [ 309.662315] vfs_write+0xc6/0x1f0 [ 309.662319] SyS_write+0x44/0xb0 [ 309.662323] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662329] stack backtrace: [ 309.662335] CPU: 1 PID: 6435 Comm: gem_exec_gttfil Tainted: G W 4.11.0-rc1-CI-CI_DRM_2333+ #1 [ 309.662342] Hardware name: Hewlett-Packard HP Compaq 8100 Elite SFF PC/304Ah, BIOS 786H1 v01.13 07/14/2011 [ 309.662348] Call Trace: [ 309.662354] dump_stack+0x67/0x92 [ 309.662359] print_irq_inversion_bug.part.19+0x1a4/0x1b0 [ 309.662365] check_usage_forwards+0x12b/0x130 [ 309.662369] mark_lock+0x360/0x6f0 [ 309.662374] ? print_shortest_lock_dependencies+0x1a0/0x1a0 [ 309.662379] __lock_acquire+0x638/0x1b50 [ 309.662383] ? __mutex_unlock_slowpath+0x3e/0x2e0 [ 309.662388] ? trace_hardirqs_on+0xd/0x10 [ 309.662392] ? _rcu_barrier+0x31/0x160 [ 309.662396] lock_acquire+0xc9/0x220 [ 309.662400] ? _rcu_barrier+0x31/0x160 [ 309.662404] ? _rcu_barrier+0x31/0x160 [ 309.662409] __mutex_lock+0x6e/0x990 [ 309.662412] ? _rcu_barrier+0x31/0x160 [ 309.662416] ? _rcu_barrier+0x31/0x160 [ 309.662421] ? synchronize_rcu_expedited+0x35/0xb0 [ 309.662426] ? _raw_spin_unlock_irqrestore+0x52/0x60 [ 309.662434] mutex_lock_nested+0x16/0x20 [ 309.662438] _rcu_barrier+0x31/0x160 [ 309.662442] rcu_barrier+0x10/0x20 [ 309.662464] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662484] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662489] simple_attr_write+0xc7/0xe0 [ 309.662494] full_proxy_write+0x4f/0x70 [ 309.662498] __vfs_write+0x23/0x120 [ 309.662503] ? rcu_read_lock_sched_held+0x75/0x80 [ 309.662507] ? rcu_sync_lockdep_assert+0x2a/0x50 [ 309.662512] ? __sb_start_write+0x102/0x210 [ 309.662516] ? vfs_write+0x17d/0x1f0 [ 309.662520] vfs_write+0xc6/0x1f0 [ 309.662524] ? trace_hardirqs_on_caller+0xe7/0x200 [ 309.662529] SyS_write+0x44/0xb0 [ 309.662533] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662537] RIP: 0033:0x7f507eac24a0 [ 309.662541] RSP: 002b:00007fffda8720e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 309.662548] RAX: ffffffffffffffda RBX: ffffffff81482bd3 RCX: 00007f507eac24a0 [ 309.662552] RDX: 0000000000000005 RSI: 00007fffda8720f0 RDI: 0000000000000005 [ 309.662557] RBP: ffffc9000048bf88 R08: 0000000000000000 R09: 000000000000002c [ 309.662561] R10: 0000000000000014 R11: 0000000000000246 R12: 00007fffda872230 [ 309.662566] R13: 00007fffda872228 R14: 0000000000000201 R15: 00007fffda8720f0 [ 309.662572] ? __this_cpu_preempt_check+0x13/0x20 Fixes: 0eafec6d3244 ("drm/i915: Enable lockless lookup of request tracking via RCU") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100192 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: <stable@vger.kernel.org> # v4.9+ Link: http://patchwork.freedesktop.org/patch/msgid/20170314115019.18127-1-chris@chris-wilson.co.uk Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> 2017-03-01drm/i915: Prevent concurrent tiling/framebuffer modificationsChris Wilson Reintroduce a lock around tiling vs framebuffer creation to prevent modification of the obj->tiling_and_stride whilst the framebuffer is being created. Rather than use struct_mutex once again, use the per-object lock - this will also be required in future to prevent changing the tiling whilst submitting rendering. Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Fixes: 24dbf51a5517 ("drm/i915: struct_mutex is not required for allocating the framebuffer") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170301154128.2841-2-chris@chris-wilson.co.uk 2017-02-16drm/i915: Remove struct_mutex for destroying framebuffersChris Wilson We do not need to hold struct_mutex for destroying drm_i915_gem_objects any longer, and with a little care taken over tracking obj->framebuffer_references, we can relinquish BKL locking around the destroy of intel_framebuffer. v2: Use atomic check for WARN_ON framebuffer miscounting Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170216094621.3426-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> 2017-02-08drm/i915: i915_gem_shrink_all() needs an awake deviceChris Wilson Since to unbind an object, we may need a powered up device to access the GTT entries, we only shrink bound objects if awake. Callers to i915_gem_shrink_all() had to take this into account and take the rpm wakeref, but we can move this wakeref into the shrink_all itself for convenience and making the function live up to its name. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/20170208104710.18089-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com> 2016-12-13Merge tag 'drm-for-v4.10' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds Pull drm updates from Dave Airlie: "This is the main pull request for drm for 4.10 kernel. New drivers: - ZTE VOU display driver (zxdrm) - Amlogic Meson Graphic Controller GXBB/GXL/GXM SoCs (meson) - MXSFB support (mxsfb) Core: - Format handling has been reworked - Better atomic state debugging - drm_mm leak debugging - Atomic explicit fencing support - fbdev helper ops - Documentation updates - MST fbcon fixes Bridge: - Silicon Image SiI8620 driver Panel: - Add support for new simple panels i915: - GVT Device model - Better HDMI2.0 support on skylake - More watermark fixes - GPU idling rework for suspend/resume - DP Audio workarounds - Scheduler prep-work - Opregion CADL handling - GPU scheduler and priority boosting amdgfx/radeon: - Support for virtual devices - New VM manager for non-contig VRAM buffers - UVD powergating - SI register header cleanup - Cursor fixes - Powermanagement fixes nouveau: - Powermangement reworks for better voltage/clock changes - Atomic modesetting support - Displayport Multistream (MST) support. - GP102/104 hang and cursor fixes - GP106 support hisilicon: - hibmc support (BMC chip for aarch64 servers) armada: - add tracing support for overlay change - refactor plane support - de-midlayer the driver omapdrm: - Timing code cleanups rcar-du: - R8A7792/R8A7796 support - Misc fixes. sunxi: - A31 SoC display engine support imx-drm: - YUV format support - Cleanup plane atomic update mali-dp: - Misc fixes dw-hdmi: - Add support for HDMI i2c master controller tegra: - IOMMU support fixes - Error handling fixes tda998x: - Fix connector registration - Improved robustness - Fix infoframe/audio compliance virtio: - fix busid issues - allocate more vbufs qxl: - misc fixes and cleanups. vc4: - Fragment shader threading - ETC1 support - VEC (tv-out) support msm: - A5XX GPU support - Lots of atomic changes tilcdc: - Misc fixes and cleanups. etnaviv: - Fix dma-buf export path - DRAW_INSTANCED support - fix driver on i.MX6SX exynos: - HDMI refactoring fsl-dcu: - fbdev changes" * tag 'drm-for-v4.10' of git://people.freedesktop.org/~airlied/linux: (1343 commits) drm/nouveau/kms/nv50: fix atomic regression on original G80 drm/nouveau/bl: Do not register interface if Apple GMUX detected drm/nouveau/bl: Assign different names to interfaces drm/nouveau/bios/dp: fix handling of LevelEntryTableIndex on DP table 4.2 drm/nouveau/ltc: protect clearing of comptags with mutex drm/nouveau/gr/gf100-: handle GPC/TPC/MPC trap drm/nouveau/core: recognise GP106 chipset drm/nouveau/ttm: wait for bo fence to signal before unmapping vmas drm/nouveau/gr/gf100-: FECS intr handling is not relevant on proprietary ucode drm/nouveau/gr/gf100-: properly ack all FECS error interrupts drm/nouveau/fifo/gf100-: recover from host mmu faults drm: Add fake controlD* symlinks for backwards compat drm/vc4: Don't use drm_put_dev drm/vc4: Document VEC DT binding drm/vc4: Add support for the VEC (Video Encoder) IP drm: Add TV connector states to drm_connector_state drm: Turn DRM_MODE_SUBCONNECTOR_xx definitions into an enum drm/vc4: Fix ->clock_select setting for the VEC encoder drm/amdgpu/dce6: Set MASTER_UPDATE_MODE to 0 in resume_mc_access as well drm/amdgpu: use pin rather than pin_restricted in a few cases ... 2016-11-15locking/mutex, drm: Introduce mutex_trylock_recursive()Peter Zijlstra By popular DRM demand, introduce mutex_trylock_recursive() to fix up the two GEM users. Without this it is very easy for these drivers to get stuck in low-memory situations and trigger OOM. Work is in progress to remove the need for this in at least i915. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Jason Low <jason.low2@hpe.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Clark <robdclark@gmail.com> Cc: Terry Rudd <terry.rudd@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <Will.Deacon@arm.com> Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 2016-11-03locking/drm: Fix i915_gem_shrinker_lock() lockingIngo Molnar Mike Krinkin reported hangs in the DRM code and bisected it to: 3ab7c086d5ec72585ef0 ("locking/drm: Kill mutex trickery") Hugh Dickins observed: "i915_gem_shrinker_lock() is broken: but copy the pattern from msm_gem_shrinker_lock() and it's okay - patch below." Pick up the fix in isolation to make sure the bug is fixed, cleanup patch will follow up. Originally-From: Hugh Dickins <hughd@google.com> Reported-by: Hugh Dickins <hughd@google.com> Reported-by: Mike Krinkin <krinkin.m.u@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Airlie <airlied@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: chris@chris-wilson.co.uk Cc: jason.low2@hpe.com Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1610301645180.28429@eggly.anvils Signed-off-by: Ingo Molnar <mingo@kernel.org> 2016-11-02drm/i915: Unify global_list into global_linkJoonas Lahtinen $ sed -i -r 's/\bglobal_list\b/global_link/g' *.c *.h Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/1478081764-8058-1-git-send-email-joonas.lahtinen@linux.intel.com 2016-11-01drm/i915: Allow shrinking of userptr objects once againTvrtko Ursulin Commit 1bec9b0bda3d ("drm/i915/shrinker: Only shmemfs objects are backed by swap") stopped considering the userptr objects in shrinker callbacks. Restore that so idle userptr objects can be discarded in order to free up memory. One change further to what was introduced in 1bec9b0bda3d is to start considering userptr objects in oom but that should also be a correct thing to do. v2: Introduce I915_GEM_OBJECT_IS_SHRINKABLE. (Chris Wilson) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Fixes: 1bec9b0bda3d ("drm/i915/shrinker: Only shmemfs objects are backed by swap") Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: <stable@vger.kernel.org> Link: http://patchwork.freedesktop.org/patch/msgid/1478011450-6634-1-git-send-email-tvrtko.ursulin@linux.intel.com 2016-11-01drm/i915: Improve lockdep tracking for obj->mm.lockChris Wilson The shrinker may appear to recurse into obj->mm.lock as the shrinker may be called from a direct reclaim path whilst handling get_pages. We filter out recursing on the same obj->mm.lock by inspecting obj->mm.pages, but we do want to take the lock on a second object in order to reap their pages. lockdep spots the recursion on the same lockclass and needs annotation to avoid a false positive. To keep the two paths distinct, create an enum to indicate which subclass of obj->mm.lock we are using. This removes the false positive and avoids masking real bugs. Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161101121134.27504-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> 2016-11-01drm/i915: Move the recently scanned objects to the tail after shrinkingChris Wilson During shrinking, we walk over the list of objects searching for victims. Any that are not removed are put back into the global list. Currently, they are put back in order (at the front) which means they will be first to be scanned again. If we instead move them to the rear of the list, we will scan new potential victims on the next pass and waste less time rescanning unshrinkable objects. Normally the lists are kept in rough order to shrinking (with object least frequently used at the start), by moving just scanned objects to the rear we are acknowledging that they are still in use. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161101084843.3961-3-chris@chris-wilson.co.uk 2016-11-01drm/i915: Discard objects from mm global_list after being shrunkChris Wilson In the shrinker, we can safely remove an empty object (obj->mm.pages == NULL) after having discarded the pages because we are holding the struct_mutex. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161101084843.3961-2-chris@chris-wilson.co.uk 2016-10-31drm/i915: Mark up obj->mm.lock for shrinkerChris Wilson As we may allocate from within the obj->mm.lock we may enter the shrinker for direct reclaim. Operating on the current object is prevented by checking for obj->mm.pages (which is only set as the last operation in the allocation path). However, we need to identify the single recursion of accessing another object's obj->mm.lock as the two locks have identical class and so appear to be the same to lockdep, convincing it that a deadlock is possible. Use mutex_lock_nested() to remove the false positive. [ 2165.945734] ================================= [ 2165.945749] [ INFO: inconsistent lock state ] [ 2165.945765] 4.9.0-rc2+ #2 Tainted: G W [ 2165.945781] --------------------------------- [ 2165.945796] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. [ 2165.945816] kswapd0/62 [HC0[0]:SC0[0]:HE1:SE1] takes: (&obj->mm.lock){+.+.?.}, at: [<ffffffffc0289a1f>] i915_gem_shrink+0x29f/0x500 [i915] [ 2165.945904] {RECLAIM_FS-ON-W} state was registered at: [ 2165.945931] [<ffffffffb10bd50f>] mark_held_locks+0x6f/0xa0 [ 2165.945956] [<ffffffffb10bf889>] lockdep_trace_alloc+0x69/0xc0 [ 2165.945982] [<ffffffffb11eea53>] kmem_cache_alloc_trace+0x33/0x2a0 [ 2165.946019] [<ffffffffc028a28a>] i915_gem_object_get_pages_stolen+0x6a/0xd0 [i915] [ 2165.946060] [<ffffffffc027e1d0>] ____i915_gem_object_get_pages+0x20/0x60 [i915] [ 2165.946098] [<ffffffffc027e268>] __i915_gem_object_get_pages+0x58/0x70 [i915] [ 2165.946138] [<ffffffffc028a3dc>] _i915_gem_object_create_stolen+0xec/0x120 [i915] [ 2165.946177] [<ffffffffc028af73>] i915_gem_object_create_stolen_for_preallocated+0xf3/0x3f0 [i915] [ 2165.946222] [<ffffffffc02bae43>] intel_alloc_initial_plane_obj.isra.125+0xd3/0x200 [i915] [ 2165.946266] [<ffffffffc02cb1c1>] intel_modeset_init+0x931/0x1530 [i915] [ 2165.946301] [<ffffffffc023d584>] i915_driver_load+0xa14/0x14a0 [i915] [ 2165.946335] [<ffffffffc0248aff>] i915_pci_probe+0x4f/0x70 [i915] [ 2165.946362] [<ffffffffb13cc452>] local_pci_probe+0x42/0xa0 [ 2165.946386] [<ffffffffb13cd903>] pci_device_probe+0x103/0x150 [ 2165.946411] [<ffffffffb14adeb3>] driver_probe_device+0x223/0x430 [ 2165.946436] [<ffffffffb14ae1a3>] __driver_attach+0xe3/0xf0 [ 2165.946461] [<ffffffffb14ab943>] bus_for_each_dev+0x73/0xc0 [ 2165.946485] [<ffffffffb14ad5ee>] driver_attach+0x1e/0x20 [ 2165.946508] [<ffffffffb14ad003>] bus_add_driver+0x173/0x270 [ 2165.946533] [<ffffffffb14aee70>] driver_register+0x60/0xe0 [ 2165.946557] [<ffffffffb13cbd6d>] __pci_register_driver+0x5d/0x60 [ 2165.946606] [<ffffffffc0378057>] soundcore_open+0x17/0x230 [soundcore] [ 2165.946636] [<ffffffffb1000450>] do_one_initcall+0x50/0x180 [ 2165.946661] [<ffffffffb117fd2d>] do_init_module+0x5f/0x1f1 [ 2165.946685] [<ffffffffb1108964>] load_module+0x2174/0x2a80 [ 2165.946709] [<ffffffffb11094df>] SYSC_finit_module+0xdf/0x110 [ 2165.946734] [<ffffffffb110952e>] SyS_finit_module+0xe/0x10 [ 2165.946758] [<ffffffffb1742aea>] entry_SYSCALL_64_fastpath+0x18/0xad [ 2165.946776] irq event stamp: 90871 [ 2165.946788] hardirqs last enabled at (90871): [ 2165.946805] [<ffffffffb173e9da>] __mutex_unlock_slowpath+0x11a/0x1c0 [ 2165.946823] hardirqs last disabled at (90870): [ 2165.946839] [<ffffffffb173e91b>] __mutex_unlock_slowpath+0x5b/0x1c0 [ 2165.946856] softirqs last enabled at (90858): [ 2165.946872] [<ffffffffb174581a>] __do_softirq+0x39a/0x4c6 [ 2165.946887] softirqs last disabled at (90671): [ 2165.946902] [<ffffffffb1066cea>] irq_exit+0xea/0xf0 [ 2165.946916] other info that might help us debug this: [ 2165.946936] Possible unsafe locking scenario: [ 2165.946955] CPU0 [ 2165.946965] ---- [ 2165.946975] lock(&obj->mm.lock); [ 2165.947000] <Interrupt> [ 2165.947010] lock(&obj->mm.lock); [ 2165.947035] *** DEADLOCK *** [ 2165.947054] 2 locks held by kswapd0/62: [ 2165.947067] #0: (shrinker_rwsem){++++..}, at: [<ffffffffb119a20e>] shrink_slab.part.40+0x5e/0x5d0 [ 2165.947120] #1: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffc028954b>] i915_gem_shrinker_lock+0x1b/0x60 [i915] [ 2165.948909] stack backtrace: [ 2165.950650] CPU: 2 PID: 62 Comm: kswapd0 Tainted: G W 4.9.0-rc2+ #2 [ 2165.951587] Hardware name: LENOVO 80MX/Lenovo E31-80, BIOS DCCN34WW(V2.03) 12/01/2015 [ 2165.952484] ffffc90000b5f8c8 ffffffffb137f645 ffff88016c5a2700 ffffffffb25f20a0 [ 2165.953395] ffffc90000b5f918 ffffffffb10bcecd 0000000000000000 ffff880100000001 [ 2165.954305] 0000000000000001 000000000000000a ffff88016c5a2fd0 ffff88016c5a2700 [ 2165.955240] Call Trace: [ 2165.956170] [<ffffffffb137f645>] dump_stack+0x68/0x93 [ 2165.957071] [<ffffffffb10bcecd>] print_usage_bug+0x1dd/0x1f0 [ 2165.957979] [<ffffffffb10bd439>] mark_lock+0x559/0x5c0 [ 2165.958875] [<ffffffffb10bc3f0>] ? print_shortest_lock_dependencies+0x1b0/0x1b0 [ 2165.959829] [<ffffffffb10be04d>] __lock_acquire+0x66d/0x12a0 [ 2165.960729] [<ffffffffb11ef541>] ? __slab_free+0xa1/0x340 [ 2165.961625] [<ffffffffb10dba5d>] ? debug_lockdep_rcu_enabled+0x1d/0x20 [ 2165.962530] [<ffffffffb10bd50f>] ? mark_held_locks+0x6f/0xa0 [ 2165.963457] [<ffffffffb10bf0b0>] lock_acquire+0xf0/0x1f0 [ 2165.964368] [<ffffffffc0289a1f>] ? i915_gem_shrink+0x29f/0x500 [i915] [ 2165.965269] [<ffffffffc0289a1f>] ? i915_gem_shrink+0x29f/0x500 [i915] [ 2165.966150] [<ffffffffb173d837>] mutex_lock_nested+0x77/0x420 [ 2165.967030] [<ffffffffc0289a1f>] ? i915_gem_shrink+0x29f/0x500 [i915] [ 2165.967952] [<ffffffffc027c7a1>] ? __i915_gem_object_put_pages.part.58+0x161/0x1b0 [i915] [ 2165.968835] [<ffffffffc0289a1f>] i915_gem_shrink+0x29f/0x500 [i915] [ 2165.969712] [<ffffffffc0289e40>] i915_gem_shrinker_scan+0x70/0xb0 [i915] [ 2165.970591] [<ffffffffb119a3ae>] shrink_slab.part.40+0x1fe/0x5d0 [ 2165.971504] [<ffffffffb119f19c>] shrink_node+0x22c/0x320 [ 2165.972371] [<ffffffffb11a05fb>] kswapd+0x38b/0x9b0 [ 2165.973238] [<ffffffffb11a0270>] ? mem_cgroup_shrink_node+0x330/0x330 [ 2165.974068] [<ffffffffb108630f>] kthread+0xff/0x120 [ 2165.974929] [<ffffffffb1086210>] ? kthread_park+0x60/0x60 [ 2165.975847] [<ffffffffb1742d57>] ret_from_fork+0x27/0x40 Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Fixes: 1233e2db199d ("drm/i915: Move object backing storage manipulation...") Testcase: igt/gem_ctx_create/maximum-swap Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161031124048.30355-1-chris@chris-wilson.co.uk 2016-10-28drm/i915: Move object release to a freelist + workerChris Wilson We want to hide the latency of releasing objects and their backing storage from the submission, so we move the actual free to a worker. This allows us to switch to struct_mutex freeing of the object in the next patch. Furthermore, if we know that the object we are dereferencing remains valid for the duration of our access, we can forgo the usual synchronisation barriers and atomic reference counting. To ensure this we defer freeing an object til after an RCU grace period, such that any lookup of the object within an RCU read critical section will remain valid until after we exit that critical section. We also employ this delay for rate-limiting the serialisation on reallocation - we have to slow down object creation in order to prevent resource starvation (in particular, files). v2: Return early in i915_gem_tiling() ioctl to skip over superfluous work on error. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-19-chris@chris-wilson.co.uk 2016-10-28drm/i915: Move object backing storage manipulation to its own lockingChris Wilson Break the allocation of the backing storage away from struct_mutex into a per-object lock. This allows parallel page allocation, provided we can do so outside of struct_mutex (i.e. set-domain-ioctl, pwrite, GTT fault), i.e. before execbuf! The increased cost of the atomic counters are hidden behind i915_vma_pin() for the typical case of execbuf, i.e. as the object is typically bound between execbufs, the page_pin_count is static. The cost will be felt around set-domain and pwrite, but offset by the improvement from reduced struct_mutex contention. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-14-chris@chris-wilson.co.uk 2016-10-28drm/i915: Pass around sg_table to get_pages/put_pages backendChris Wilson The plan is to move obj->pages out from under the struct_mutex into its own per-object lock. We need to prune any assumption of the struct_mutex from the get_pages/put_pages backends, and to make it easier we pass around the sg_table to operate on rather than indirectly via the obj. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-13-chris@chris-wilson.co.uk 2016-10-28drm/i915: Refactor object page APIChris Wilson The plan is to make obtaining the backing storage for the object avoid struct_mutex (i.e. use its own locking). The first step is to update the API so that normal users only call pin/unpin whilst working on the backing storage. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-12-chris@chris-wilson.co.uk 2016-10-25locking/drm: Kill mutex trickeryPeter Zijlstra Poking at lock internals is not cool. Since I'm going to change the implementation this will break, take it out. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Clark <robdclark@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>