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2017-03-16afs: Flush outstanding writes when an fd is closedDavid Howells
Flush outstanding writes in afs when an fd is closed. This is what NFS and CIFS do. Reported-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Handle a short write to an AFS pageDavid Howells
Handle the situation where afs_write_begin() is told to expect that a full-page write will be made, but this doesn't happen (EFAULT, CTRL-C, etc.), and so afs_write_end() sees a partial write took place. Currently, no attempt is to deal with the discrepency. Fix this by loading the gap from the server. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Kill struct afs_read::pg_offsetDavid Howells
Kill struct afs_read::pg_offset as nothing uses it. It's unnecessary as pos can be masked off. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Handle better the server returning excess or short dataDavid Howells
When an AFS server is given an FS.FetchData{,64} request to read data from a file, it is permitted by the protocol to return more or less than was requested. kafs currently relies on the latter behaviour in readpage{,s} to handle a partial page at the end of the file (we just ask for a whole page and clear space beyond the short read). However, we don't handle all cases. Add: (1) Handle excess data by discarding it rather than aborting. Note that we use a common static buffer to discard into so that the decryption algorithm advances the PCBC state. (2) Handle a short read that affects more than just the last page. Note that if a read comes up unexpectedly short of long, it's possible that the server's copy of the file changed - in which case the data version number will have been incremented and the callback will have been broken - in which case all the pages currently attached to the inode will be zapped anyway at some point. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Deal with an empty callback arrayMarc Dionne
Servers may send a callback array that is the same size as the FID array, or an empty array. If the callback count is 0, the code would attempt to read (fid_count * 12) bytes of data, which would fail and result in an unmarshalling error. This would lead to stale data for remotely modified files or directories. Store the callback array size in the internal afs_call structure and use that to determine the amount of data to read. Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Adjust mode bits processingMarc Dionne
Mode bits for an afs file should not be enforced in the usual way. For files, the absence of user bits can restrict file access with respect to what is granted by the server. These bits apply regardless of the owner or the current uid; the rest of the mode bits (group, other) are ignored. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Populate group ID from vnode statusMarc Dionne
The group was hard coded to GLOBAL_ROOT_GID; use the group ID that was received from the server. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix page overput in afs_fill_page()David Howells
afs_fill_page() loads the page it wants to fill into the afs_read request without incrementing its refcount - but then calls afs_put_read() to clean up afterwards, which then releases a ref on the page. Fix this by getting a ref on the page before calling afs_vnode_fetch_data(). This causes sync after a write to hang in afs_writepages_region() because find_get_pages_tag() gets confused and doesn't return. Fixes: 196ee9cd2d04 ("afs: Make afs_fs_fetch_data() take a list of pages") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Fix missing put_page()David Howells
In afs_writepages_region(), inside the loop where we find dirty pages to deal with, one of the if-statements is missing a put_page(). Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16drm/i915: make context status notifier head be per engineChangbin Du
GVTg has introduced the context status notifier to schedule the GVTg workload. At that time, the notifier is bound to GVTg context only, so GVTg is not aware of host workloads. Now we are going to improve GVTg's guest workload scheduler policy, and add Guc emulation support for new Gen graphics. Both these two features require acknowledgment for all contexts running on hardware. (But will not alter host workload.) So here try to make some change. The change is simple: 1. Move the context status notifier head from i915_gem_context to intel_engine_cs. Which means there is a notifier head per engine instead of per context. Execlist driver still call notifier for each context sched-in/out events of current engine. 2. At GVTg side, it binds a notifier_block for each physical engine at GVTg initialization period. Then GVTg can hear all context status events. In this patch, GVTg do nothing for host context event, but later will add a function there. But in any case, the notifier callback is a noop if this is no active vGPU. Since intel_gvt_init() is called at early initialization stage and require the status notifier head has been initiated, I initiate it in intel_engine_setup(). v2: remove a redundant newline. (chris) Fixes: 3c7ba6359d70 ("drm/i915: Introduce execlist context status change notification") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100232 Signed-off-by: Changbin Du <changbin.du@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Zhi Wang <zhi.a.wang@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/20170313024711.28591-1-changbin.du@intel.com Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/i915/scheduler: emulate a scheduler for gucChris Wilson
This emulates execlists on top of the GuC in order to defer submission of requests to the hardware. This deferral allows time for high priority requests to gazump their way to the head of the queue, however it nerfs the GuC by converting it back into a simple execlist (where the CPU has to wake up after every request to feed new commands into the GuC). v2: Drop hack status - though iirc there is still a lockdep inversion between fence and engine->timeline->lock (which is impossible as the nesting only occurs on different fences - hopefully just requires some judicious lockdep annotation) v3: Apply lockdep nesting to enabling signaling on the request, using the pattern we already have in __i915_gem_request_submit(); v4: Replaying requests after a hang also now needs the timeline spinlock, to disable the interrupts at least v5: Hold wq lock for completeness, and emit a tracepoint for enabling signal v6: Reorder interrupt checking for a happier gcc. v7: Only signal the tasklet after a user-interrupt if using guc scheduling v8: Restore lost update of rq through the i915_guc_irq_handler (Tvrtko) v9: Avoid re-initialising the engine->irq_tasklet from inside a reset v10: Hook up the execlists-style tracepoints v11: Clear the execlists irq_posted bit after taking over the interrupt/tasklet Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170316125619.6856-1-chris@chris-wilson.co.uk Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
2017-03-16drm/i915: Replace irq_seqno_barrier on hws write with a clflushChris Wilson
When manually overwriting the HWS, rather than assume irq_seqno_barrier does the right thing, we can explicitly flush the cacheline instead. This avoids us calling the engine->irq_seqno_barrier() from an illegal context: [ 1472.651797] BUG: scheduling while atomic: migration/0/11/0x00000002 [ 1472.651807] Modules linked in: ctr ccm arc4 snd_hda_codec_hdmi bnep rfcomm iwldvm snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel mac80211 snd_hda_codec snd_hda_core snd_pcm dm_multipath snd_hwdep intel_powerclamp coretemp snd_seq_midi crct10dif_pclmul snd_seq_midi_event crc32_pclmul iwlwifi ghash_clmulni_intel btusb snd_rawmidi btrtl aesni_intel btbcm aes_x86_64 crypto_simd btintel cryptd glue_helper bluetooth snd_seq cfg80211 snd_timer snd_seq_device intel_ips binfmt_misc snd mei_me soundcore mei dm_mirror dm_region_hash dm_log i915 intel_gtt i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea prime_numbers e1000e drm ahci libahci [ 1472.651897] CPU: 0 PID: 11 Comm: migration/0 Tainted: G U 4.11.0-rc1+ #203 [ 1472.651899] Hardware name: LENOVO 514328U/514328U, BIOS 6QET44WW (1.14 ) 04/20/2010 [ 1472.651900] Call Trace: [ 1472.651913] dump_stack+0x63/0x90 [ 1472.651922] __schedule_bug+0x5d/0x6b [ 1472.651930] __schedule+0x46a/0x5f0 [ 1472.651934] schedule+0x38/0x90 [ 1472.651938] schedule_hrtimeout_range_clock+0x85/0x110 [ 1472.651945] ? hrtimer_init+0x10/0x10 [ 1472.651949] schedule_hrtimeout_range+0xe/0x10 [ 1472.651952] usleep_range+0x4d/0x60 [ 1472.652037] gen5_seqno_barrier+0x13/0x20 [i915] [ 1472.652101] intel_engine_init_global_seqno+0xd7/0x160 [i915] [ 1472.652160] __i915_gem_set_wedged_BKL+0xa0/0x180 [i915] [ 1472.652166] multi_cpu_stop+0xbb/0xe0 [ 1472.652170] ? cpu_stop_queue_work+0x90/0x90 [ 1472.652174] cpu_stopper_thread+0x82/0x110 [ 1472.652179] smpboot_thread_fn+0x137/0x190 [ 1472.652184] kthread+0xf7/0x130 [ 1472.652187] ? sort_range+0x20/0x20 [ 1472.652191] ? kthread_park+0x90/0x90 [ 1472.652195] ret_from_fork+0x2c/0x40 Testcase: igt/gem_eio #ilk Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/20170314111452.9375-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
2017-03-16perf/core: Better explain the inherit magicPeter Zijlstra
While going through the event inheritance code Oleg got confused. Add some comments to better explain the silent dissapearance of orphaned events. So what happens is that at perf_event_release_kernel() time; when an event looses its connection to userspace (and ceases to exist from the user's perspective) we can still have an arbitrary amount of inherited copies of the event. We want to synchronously find and remove all these child events. Since that requires a bit of lock juggling, there is the possibility that concurrent clone()s will create new child events. Therefore we first mark the parent event as DEAD, which marks all the extant child events as orphaned. We then avoid copying orphaned events; in order to avoid getting more of them. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: fweisbec@gmail.com Link: http://lkml.kernel.org/r/20170316125823.289567442@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Simplify perf_event_free_task()Peter Zijlstra
We have ctx->event_list that contains all events; no need to repeatedly iterate the group lists to find them all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: fweisbec@gmail.com Link: http://lkml.kernel.org/r/20170316125823.239678244@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Fix event inheritance on fork()Peter Zijlstra
While hunting for clues to a use-after-free, Oleg spotted that perf_event_init_context() can loose an error value with the result that fork() can succeed even though we did not fully inherit the perf event context. Spotted-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: oleg@redhat.com Cc: stable@vger.kernel.org Fixes: 889ff0150661 ("perf/core: Split context's event group list into pinned and non-pinned lists") Link: http://lkml.kernel.org/r/20170316125823.190342547@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16perf/core: Fix use-after-free in perf_release()Peter Zijlstra
Dmitry reported syzcaller tripped a use-after-free in perf_release(). After much puzzlement Oleg spotted the below scenario: Task1 Task2 fork() perf_event_init_task() /* ... */ goto bad_fork_$foo; /* ... */ perf_event_free_task() mutex_lock(ctx->lock) perf_free_event(B) perf_event_release_kernel(A) mutex_lock(A->child_mutex) list_for_each_entry(child, ...) { /* child == B */ ctx = B->ctx; get_ctx(ctx); mutex_unlock(A->child_mutex); mutex_lock(A->child_mutex) list_del_init(B->child_list) mutex_unlock(A->child_mutex) /* ... */ mutex_unlock(ctx->lock); put_ctx() /* >0 */ free_task(); mutex_lock(ctx->lock); mutex_lock(A->child_mutex); /* ... */ mutex_unlock(A->child_mutex); mutex_unlock(ctx->lock) put_ctx() /* 0 */ ctx->task && !TOMBSTONE put_task_struct() /* UAF */ This patch closes the hole by making perf_event_free_task() destroy the task <-> ctx relation such that perf_event_release_kernel() will no longer observe the now dead task. Spotted-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: fweisbec@gmail.com Cc: oleg@redhat.com Cc: stable@vger.kernel.org Fixes: c6e5b73242d2 ("perf: Synchronously clean up child events") Link: http://lkml.kernel.org/r/20170314155949.GE32474@worktop Link: http://lkml.kernel.org/r/20170316125823.140295131@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16drm/i915: Use coarse grained residency counter with bytMika Kuoppala
Set byt rc residency counters high level as chv does by default. We lose some accuracy on byt but we can do the calculation without extra hw read on both platforms, as now they behave identically in this respect. v2: use ktime v3: keep comparison u32 (Chris) Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/1489592584-10422-1-git-send-email-mika.kuoppala@intel.com
2017-03-16drm/i915: Use ktime to calculate rc0 residencyMika Kuoppala
We have used cz timestamp register to gain a reference time wrt to residency calculations. The residency counts are in cz clk ticks (333Mhz clock) but for some reason the cz timestamp register gives 100us units. Perhaps for some other usage, the base-ten based values are easier, but in residency calculations raw units would have been the easiest. As there is not much advantage of using base-ten clock through a more costly punit access, take our reference times directly from kernel clock. v2: use ktime (Chris, Ville) Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/i915: Convert debugfs to use generic residency calculatorMika Kuoppala
Use intel_rc6_residency to get benefit for increased resolution in byt/chv. v2: output raw and time (Chris) Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/i915: Extend vlv/chv residency resolutionMika Kuoppala
Vlv and chv residency counters are 40 bits in width. With a control bit, we can choose between upper or lower 32 bit window into this counter. Lets toggle this bit on and off on and read both parts. As a result we can push the wrap from 13 seconds to 54 minutes. v2: commit msg, loop readability, goto elimination (Chris) v3: bug ref, divide outside runtime pm lock (Chris) References: https://bugs.freedesktop.org/show_bug.cgi?id=94852 Reported-by: Len Brown <len.brown@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/i915: Return residency as microsecondsMika Kuoppala
Change the granularity from milliseconds to microseconds when returning rc6 residencies. This is in preparation for increased resolution on some platforms. v2: use 64bit div macro (Chris) Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/i915: Move residency calculation into intel_pm.cMika Kuoppala
Plan is to make generic residency calculation utility function for usage outside of sysfs. As a first step move residency calculation into intel_pm.c Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
2017-03-16drm/atmel-hlcdc: Fix suspend/resume implementationBoris Brezillon
The current suspend resume implementation is assuming register values are kept when entering suspend, which is no longer the case with the suspend-to-RAM on the sama5d2. While at it, switch to the generic infrastructure to enter suspend mode (drm_atomic_helper_suspend/resume()). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Sylvain Rochet <sylvain.rochet@finsecur.com> Link: http://patchwork.freedesktop.org/patch/msgid/1488371461-22243-1-git-send-email-boris.brezillon@free-electrons.com
2017-03-16drm/i915/userptr: Reinvent GGTT self-faulting protectionChris Wilson
lockdep doesn't like us taking the mm->mmap_sem inside the get_pages callback for a couple of reasons. The straightforward deadlock: [13755.434059] ============================================= [13755.434061] [ INFO: possible recursive locking detected ] [13755.434064] 4.11.0-rc1-CI-CI_DRM_297+ #1 Tainted: G U [13755.434066] --------------------------------------------- [13755.434068] gem_userptr_bli/8398 is trying to acquire lock: [13755.434070] (&mm->mmap_sem){++++++}, at: [<ffffffffa00c988a>] i915_gem_userptr_get_pages+0x5a/0x2e0 [i915] [13755.434096] but task is already holding lock: [13755.434098] (&mm->mmap_sem){++++++}, at: [<ffffffff8104d485>] __do_page_fault+0x105/0x560 [13755.434105] other info that might help us debug this: [13755.434108] Possible unsafe locking scenario: [13755.434110] CPU0 [13755.434111] ---- [13755.434112] lock(&mm->mmap_sem); [13755.434115] lock(&mm->mmap_sem); [13755.434117] *** DEADLOCK *** [13755.434121] May be due to missing lock nesting notation [13755.434126] 2 locks held by gem_userptr_bli/8398: [13755.434128] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104d485>] __do_page_fault+0x105/0x560 [13755.434135] #1: (&obj->mm.lock){+.+.+.}, at: [<ffffffffa00b887d>] __i915_gem_object_get_pages+0x1d/0x70 [i915] [13755.434156] stack backtrace: [13755.434161] CPU: 3 PID: 8398 Comm: gem_userptr_bli Tainted: G U 4.11.0-rc1-CI-CI_DRM_297+ #1 [13755.434165] Hardware name: GIGABYTE GB-BKi7(H)A-7500/MFLP7AP-00, BIOS F4 02/20/2017 [13755.434169] Call Trace: [13755.434174] dump_stack+0x67/0x92 [13755.434178] __lock_acquire+0x133a/0x1b50 [13755.434182] lock_acquire+0xc9/0x220 [13755.434200] ? i915_gem_userptr_get_pages+0x5a/0x2e0 [i915] [13755.434204] down_read+0x42/0x70 [13755.434221] ? i915_gem_userptr_get_pages+0x5a/0x2e0 [i915] [13755.434238] i915_gem_userptr_get_pages+0x5a/0x2e0 [i915] [13755.434255] ____i915_gem_object_get_pages+0x25/0x60 [i915] [13755.434272] __i915_gem_object_get_pages+0x59/0x70 [i915] [13755.434288] i915_gem_fault+0x397/0x6a0 [i915] [13755.434304] ? i915_gem_fault+0x1a1/0x6a0 [i915] [13755.434308] ? __lock_acquire+0x449/0x1b50 [13755.434311] ? __lock_acquire+0x449/0x1b50 [13755.434315] ? vm_mmap_pgoff+0xa9/0xd0 [13755.434318] __do_fault+0x19/0x70 [13755.434321] __handle_mm_fault+0x863/0xe50 [13755.434325] handle_mm_fault+0x17f/0x370 [13755.434329] ? handle_mm_fault+0x40/0x370 [13755.434332] __do_page_fault+0x279/0x560 [13755.434336] do_page_fault+0xc/0x10 [13755.434339] page_fault+0x22/0x30 [13755.434342] RIP: 0033:0x7f5ab91b5880 [13755.434345] RSP: 002b:00007fff62922218 EFLAGS: 00010216 [13755.434348] RAX: 0000000000b74500 RBX: 00007f5ab7f81000 RCX: 0000000000000000 [13755.434352] RDX: 0000000000100000 RSI: 00007f5ab7f81000 RDI: 00007f5aba61c000 [13755.434355] RBP: 00007f5aba61c000 R08: 0000000000000007 R09: 0000000100000000 [13755.434359] R10: 000000000000037d R11: 00007f5ab91b5840 R12: 0000000000000001 [13755.434362] R13: 0000000000000005 R14: 0000000000000001 R15: 0000000000000000 and cyclic deadlocks: [ 2566.458979] ====================================================== [ 2566.459054] [ INFO: possible circular locking dependency detected ] [ 2566.459127] 4.11.0-rc1+ #26 Not tainted [ 2566.459194] ------------------------------------------------------- [ 2566.459266] gem_streaming_w/759 is trying to acquire lock: [ 2566.459334] (&obj->mm.lock){+.+.+.}, at: [<ffffffffa034bc80>] i915_gem_object_pin_pages+0x0/0xc0 [i915] [ 2566.459605] [ 2566.459605] but task is already holding lock: [ 2566.459699] (&mm->mmap_sem){++++++}, at: [<ffffffff8106fd11>] __do_page_fault+0x121/0x500 [ 2566.459814] [ 2566.459814] which lock already depends on the new lock. [ 2566.459814] [ 2566.459934] [ 2566.459934] the existing dependency chain (in reverse order) is: [ 2566.460030] [ 2566.460030] -> #1 (&mm->mmap_sem){++++++}: [ 2566.460139] lock_acquire+0xfe/0x220 [ 2566.460214] down_read+0x4e/0x90 [ 2566.460444] i915_gem_userptr_get_pages+0x6e/0x340 [i915] [ 2566.460669] ____i915_gem_object_get_pages+0x8b/0xd0 [i915] [ 2566.460900] __i915_gem_object_get_pages+0x6a/0x80 [i915] [ 2566.461132] __i915_vma_do_pin+0x7fa/0x930 [i915] [ 2566.461352] eb_add_vma+0x67b/0x830 [i915] [ 2566.461572] eb_lookup_vmas+0xafe/0x1010 [i915] [ 2566.461792] i915_gem_do_execbuffer+0x715/0x2870 [i915] [ 2566.462012] i915_gem_execbuffer2+0x106/0x2b0 [i915] [ 2566.462152] drm_ioctl+0x36c/0x670 [drm] [ 2566.462236] do_vfs_ioctl+0x12c/0xa60 [ 2566.462317] SyS_ioctl+0x41/0x70 [ 2566.462399] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 2566.462477] [ 2566.462477] -> #0 (&obj->mm.lock){+.+.+.}: [ 2566.462587] __lock_acquire+0x1602/0x1790 [ 2566.462661] lock_acquire+0xfe/0x220 [ 2566.462893] i915_gem_object_pin_pages+0x4c/0xc0 [i915] [ 2566.463116] i915_gem_fault+0x2c2/0x8c0 [i915] [ 2566.463197] __do_fault+0x42/0x130 [ 2566.463276] __handle_mm_fault+0x92c/0x1280 [ 2566.463356] handle_mm_fault+0x1e2/0x440 [ 2566.463443] __do_page_fault+0x1c4/0x500 [ 2566.463529] do_page_fault+0xc/0x10 [ 2566.463613] page_fault+0x1f/0x30 [ 2566.463693] [ 2566.463693] other info that might help us debug this: [ 2566.463693] [ 2566.463820] Possible unsafe locking scenario: [ 2566.463820] [ 2566.463918] CPU0 CPU1 [ 2566.463988] ---- ---- [ 2566.464068] lock(&mm->mmap_sem); [ 2566.464143] lock(&obj->mm.lock); [ 2566.464226] lock(&mm->mmap_sem); [ 2566.464304] lock(&obj->mm.lock); [ 2566.464378] [ 2566.464378] *** DEADLOCK *** [ 2566.464378] [ 2566.464504] 1 lock held by gem_streaming_w/759: [ 2566.464576] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106fd11>] __do_page_fault+0x121/0x500 [ 2566.464699] [ 2566.464699] stack backtrace: [ 2566.464801] CPU: 0 PID: 759 Comm: gem_streaming_w Not tainted 4.11.0-rc1+ #26 [ 2566.464881] Hardware name: GIGABYTE GB-BXBT-1900/MZBAYAB-00, BIOS F8 03/02/2016 [ 2566.464983] Call Trace: [ 2566.465061] dump_stack+0x68/0x9f [ 2566.465144] print_circular_bug+0x20b/0x260 [ 2566.465234] __lock_acquire+0x1602/0x1790 [ 2566.465323] ? debug_check_no_locks_freed+0x1a0/0x1a0 [ 2566.465564] ? i915_gem_object_wait+0x238/0x650 [i915] [ 2566.465657] ? debug_lockdep_rcu_enabled.part.4+0x1a/0x30 [ 2566.465749] lock_acquire+0xfe/0x220 [ 2566.465985] ? i915_sg_trim+0x1b0/0x1b0 [i915] [ 2566.466223] i915_gem_object_pin_pages+0x4c/0xc0 [i915] [ 2566.466461] ? i915_sg_trim+0x1b0/0x1b0 [i915] [ 2566.466699] i915_gem_fault+0x2c2/0x8c0 [i915] [ 2566.466939] ? i915_gem_pwrite_ioctl+0xce0/0xce0 [i915] [ 2566.467030] ? __lock_acquire+0x642/0x1790 [ 2566.467122] ? __lock_acquire+0x642/0x1790 [ 2566.467209] ? debug_lockdep_rcu_enabled+0x35/0x40 [ 2566.467299] ? get_unmapped_area+0x1b4/0x1d0 [ 2566.467387] __do_fault+0x42/0x130 [ 2566.467474] __handle_mm_fault+0x92c/0x1280 [ 2566.467564] ? __pmd_alloc+0x1e0/0x1e0 [ 2566.467651] ? vm_mmap_pgoff+0x160/0x190 [ 2566.467740] ? handle_mm_fault+0x111/0x440 [ 2566.467827] handle_mm_fault+0x1e2/0x440 [ 2566.467914] ? handle_mm_fault+0x5d/0x440 [ 2566.468002] __do_page_fault+0x1c4/0x500 [ 2566.468090] do_page_fault+0xc/0x10 [ 2566.468180] page_fault+0x1f/0x30 [ 2566.468263] RIP: 0033:0x557895ced32a [ 2566.468337] RSP: 002b:00007fffd6dd8a10 EFLAGS: 00010202 [ 2566.468419] RAX: 00007f659a4db000 RBX: 0000000000000003 RCX: 00007f659ad032da [ 2566.468501] RDX: 0000000000000000 RSI: 0000000000100000 RDI: 0000000000000000 [ 2566.468586] RBP: 0000000000000007 R08: 0000000000000003 R09: 0000000100000000 [ 2566.468667] R10: 0000000000000001 R11: 0000000000000246 R12: 0000557895ceda60 [ 2566.468749] R13: 0000000000000001 R14: 00007fffd6dd8ac0 R15: 00007f659a4db000 By checking the status of the gup worker (serialized by the obj->mm.lock) we can determine whether it is still active, has failed or has succeeded. If the worker is still active (or failed), we know that it cannot be bound and so we can skip taking struct_mutex (risking potential recursion). As we check the worker status, we mark it to discard any partial results, forcing us to restart on the next get_pages. Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Fixes: 1c8782dd313e ("drm/i915/userptr: Disallow wrapping GTT into a userptr") Testcase: igt/gem_userptr_blits/map-fixed-invalidate-gup Testcase: igt/gem_userptr_blits/dmabuf-sync Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Michał Winiarski <michal.winiarski@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315140150.19432-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
2017-03-16powerpc: Wire up statx() syscallChandan Rajendra
Test runs on a ppc64 BE guest succeeded. linux/samples/statx/test-statx program was executed on the following file types, 1. Regular file 2. Directory 3. device file 4. symlink 5. Named pipe The test run also included invoking test-statx with the runtime options provided in the main() function of test-statx.c Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-03-16drm/imx: Remove unneeded definition for structure imx_drm_componentLiu Ying
No one is using the structure imx_drm_component, so let's remove the definition to save several lines. Signed-off-by: Liu Ying <gnuiyl@gmail.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16drm/imx: use PRG/PRE when possibleLucas Stach
Allow the planes to use the PRG/PRE units as linear prefetchers when possible. This improves DRAM efficiency a bit and reduces the chance for display underflow when the memory subsystem is under load. This does not yet support scanning out tiled buffers directly, as this needs more work, but it already wires up the basic interaction between imx-drm, the IPUv3 driver and the PRG and PRE drivers. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16drm/imx: enable/disable PRG on CRTC enable/disableLucas Stach
On i.MX6 QuadPlus the PRG needs to be clocked in order to pass through the data access requests from the IDMAC. This call is a no-op for other all other SoCs. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16gpu: ipu-v3: only set non-zero AXI ID for IC when PRG is absentLucas Stach
Using non-zero AXI IDs for anything other than the display channels collides with the PRG AXI snooping, so only do this if there is no PRG present. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16gpu: ipu-v3: hook up PRG unitLucas Stach
The i.MX6 QuadPlus IPU needs to PRG unit to gain access to the data bus. Make sure it is present and available to be used. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16gpu: ipu-v3: document valid IPUv3 compatibles and extend for i.MX6 QuadPlusLucas Stach
Document the valid compatible strings for the IPUv3. On i.MX6 QuadPlus the IPU needs to know which PRG has to be used for this IPU instance. Add a "fsl,prg" property containing a phandle pointing to the correct PRG device. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-03-16gpu: ipu-v3: add driver for Prefetch Resolve GasketLucas Stach
This adds support for the i.MX6 QUadPlus PRG unit. It glues together the IPU and the PRE units. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- v4: add missing ipu_soc->prg_priv
2017-03-16drm/i915: Make intel_uc_sanitize_options() more robustMichal Wajdeczko
After negative guc fw selection we could leave guc submission flag still turned on. Reorder some checks to cover this case. While here, fix info message and return early if there is no Guc. Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com> [tursulin: fixup bad alignment] Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315133741.150420-1-michal.wajdeczko@intel.com
2017-03-16drm/i915/uc: Rename intel_uc_fw.fw to .typeArkadiusz Hiler
This field is used to determine which kind of firmware the struct describes (GuC/HuC) - the name does not reflect. The enum used here have "type" in the name, so let's go with that. Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Oscar Mateo <oscar.mateo@intel.com> Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com> Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315133415.15343-1-arkadiusz.hiler@intel.com
2017-03-16drm: Skip the waitqueue setup for vblank queriesChris Wilson
Avoid adding to the waitqueue and reprobing the current vblank if the caller is only querying the current vblank sequence and timestamp, where we know that the wait would return immediately. v2: Add CRTC identifier to debug messages Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Michel Dänzer <michel@daenzer.net> Reviewed-and-tested-by: Mario Kleiner <mario.kleiner.de@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170315204027.20160-2-chris@chris-wilson.co.uk
2017-03-16drm: Defer disabling the vblank IRQ until the next interrupt (for instant-off)Chris Wilson
On vblank instant-off systems, we can get into a situation where the cost of enabling and disabling the vblank IRQ around a drmWaitVblank query dominates. And with the advent of even deeper hardware sleep state, touching registers becomes ever more expensive. However, we know that if the user wants the current vblank counter, they are also very likely to immediately queue a vblank wait and so we can keep the interrupt around and only turn it off if we have no further vblank requests queued within the interrupt interval. After vblank event delivery, this patch adds a shadow of one vblank where the interrupt is kept alive for the user to query and queue another vblank event. Similarly, if the user is using blocking drmWaitVblanks, the interrupt will be disabled on the IRQ following the wait completion. However, if the user is simply querying the current vblank counter and timestamp, the interrupt will be disabled after every IRQ and the user will enabled it again on the first query following the IRQ. v2: Mario Kleiner - After testing this, one more thing that would make sense is to move the disable block at the end of drm_handle_vblank() instead of at the top. Turns out that if high precision timestaming is disabled or doesn't work for some reason (as can be simulated by echo 0 > /sys/module/drm/parameters/timestamp_precision_usec), then with your delayed disable code at its current place, the vblank counter won't increment anymore at all for instant queries, ie. with your other "instant query" patches. Clients which repeatedly query the counter and wait for it to progress will simply hang, spinning in an endless query loop. There's that comment in vblank_disable_and_save: "* Skip this step if there isn't any high precision timestamp * available. In that case we can't account for this and just * hope for the best. */ With the disable happening after leading edge of vblank (== hw counter increment already happened) but before the vblank counter/timestamp handling in drm_handle_vblank, that step is needed to keep the counter progressing, so skipping it is bad. Now without high precision timestamping support, a kms driver must not set dev->vblank_disable_immediate = true, as this would cause problems for clients, so this shouldn't matter, but it would be good to still make this robust against a future kms driver which might have unreliable high precision timestamping, e.g., high precision timestamping that intermittently doesn't work. v3: Patch before coffee needs extra coffee. Testcase: igt/kms_vblank Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Michel Dänzer <michel@daenzer.net> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Dave Airlie <airlied@redhat.com>, Cc: Mario Kleiner <mario.kleiner.de@gmail.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170315204027.20160-1-chris@chris-wilson.co.uk
2017-03-16drm/i915/breadcrumbs: Tweak commentaryChris Wilson
Tvrtko spotted a stale reference to b->lock (now b->rb_lock) so review the comments and try to improve them in passing. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315222259.1469-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
2017-03-16sched/deadline: Use deadline instead of period when calculating overflowSteven Rostedt (VMware)
I was testing Daniel's changes with his test case, and tweaked it a little. Instead of having the runtime equal to the deadline, I increased the deadline ten fold. Daniel's test case had: attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 2 * 1000 * 1000; /* 2 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ To make it more interesting, I changed it to: attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 20 * 1000 * 1000; /* 20 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ The results were rather surprising. The behavior that Daniel's patch was fixing came back. The task started using much more than .1% of the CPU. More like 20%. Looking into this I found that it was due to the dl_entity_overflow() constantly returning true. That's because it uses the relative period against relative runtime vs the absolute deadline against absolute runtime. runtime / (deadline - t) > dl_runtime / dl_period There's even a comment mentioning this, and saying that when relative deadline equals relative period, that the equation is the same as using deadline instead of period. That comment is backwards! What we really want is: runtime / (deadline - t) > dl_runtime / dl_deadline We care about if the runtime can make its deadline, not its period. And then we can say "when the deadline equals the period, the equation is the same as using dl_period instead of dl_deadline". After correcting this, now when the task gets enqueued, it can throttle correctly, and Daniel's fix to the throttling of sleeping deadline tasks works even when the runtime and deadline are not the same. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/02135a27f1ae3fe5fd032568a5a2f370e190e8d7.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Throttle a constrained deadline task activated after the ↵Daniel Bristot de Oliveira
deadline During the activation, CBS checks if it can reuse the current task's runtime and period. If the deadline of the task is in the past, CBS cannot use the runtime, and so it replenishes the task. This rule works fine for implicit deadline tasks (deadline == period), and the CBS was designed for implicit deadline tasks. However, a task with constrained deadline (deadine < period) might be awakened after the deadline, but before the next period. In this case, replenishing the task would allow it to run for runtime / deadline. As in this case deadline < period, CBS enables a task to run for more than the runtime / period. In a very loaded system, this can cause a domino effect, making other tasks miss their deadlines. To avoid this problem, in the activation of a constrained deadline task after the deadline but before the next period, throttle the task and set the replenishing timer to the begin of the next period, unless it is boosted. Reproducer: --------------- %< --------------- int main (int argc, char **argv) { int ret; int flags = 0; unsigned long l = 0; struct timespec ts; struct sched_attr attr; memset(&attr, 0, sizeof(attr)); attr.size = sizeof(attr); attr.sched_policy = SCHED_DEADLINE; attr.sched_runtime = 2 * 1000 * 1000; /* 2 ms */ attr.sched_deadline = 2 * 1000 * 1000; /* 2 ms */ attr.sched_period = 2 * 1000 * 1000 * 1000; /* 2 s */ ts.tv_sec = 0; ts.tv_nsec = 2000 * 1000; /* 2 ms */ ret = sched_setattr(0, &attr, flags); if (ret < 0) { perror("sched_setattr"); exit(-1); } for(;;) { /* XXX: you may need to adjust the loop */ for (l = 0; l < 150000; l++); /* * The ideia is to go to sleep right before the deadline * and then wake up before the next period to receive * a new replenishment. */ nanosleep(&ts, NULL); } exit(0); } --------------- >% --------------- On my box, this reproducer uses almost 50% of the CPU time, which is obviously wrong for a task with 2/2000 reservation. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/edf58354e01db46bf42df8d2dd32418833f68c89.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Make sure the replenishment timer fires in the next periodDaniel Bristot de Oliveira
Currently, the replenishment timer is set to fire at the deadline of a task. Although that works for implicit deadline tasks because the deadline is equals to the begin of the next period, that is not correct for constrained deadline tasks (deadline < period). For instance: f.c: --------------- %< --------------- int main (void) { for(;;); } --------------- >% --------------- # gcc -o f f.c # trace-cmd record -e sched:sched_switch \ -e syscalls:sys_exit_sched_setattr \ chrt -d --sched-runtime 490000000 \ --sched-deadline 500000000 \ --sched-period 1000000000 0 ./f # trace-cmd report | grep "{pid of ./f}" After setting parameters, the task is replenished and continue running until being throttled: f-11295 [003] 13322.113776: sys_exit_sched_setattr: 0x0 The task is throttled after running 492318 ms, as expected: f-11295 [003] 13322.606094: sched_switch: f:11295 [-1] R ==> watchdog/3:32 [0] But then, the task is replenished 500719 ms after the first replenishment: <idle>-0 [003] 13322.614495: sched_switch: swapper/3:0 [120] R ==> f:11295 [-1] Running for 490277 ms: f-11295 [003] 13323.104772: sched_switch: f:11295 [-1] R ==> swapper/3:0 [120] Hence, in the first period, the task runs 2 * runtime, and that is a bug. During the first replenishment, the next deadline is set one period away. So the runtime / period starts to be respected. However, as the second replenishment took place in the wrong instant, the next replenishment will also be held in a wrong instant of time. Rather than occurring in the nth period away from the first activation, it is taking place in the (nth period - relative deadline). Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/ac50d89887c25285b47465638354b63362f8adff.1488392936.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16locking/rwsem: Fix down_write_killable() for CONFIG_RWSEM_GENERIC_SPINLOCK=yNiklas Cassel
We hang if SIGKILL has been sent, but the task is stuck in down_read() (after do_exit()), even though no task is doing down_write() on the rwsem in question: INFO: task libupnp:21868 blocked for more than 120 seconds. libupnp D 0 21868 1 0x08100008 ... Call Trace: __schedule() schedule() __down_read() do_exit() do_group_exit() __wake_up_parent() This bug has already been fixed for CONFIG_RWSEM_XCHGADD_ALGORITHM=y in the following commit: 04cafed7fc19 ("locking/rwsem: Fix down_write_killable()") ... however, this bug also exists for CONFIG_RWSEM_GENERIC_SPINLOCK=y. Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <mhocko@suse.com> Cc: <stable@vger.kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Niklas Cassel <niklass@axis.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d47996082f52 ("locking/rwsem: Introduce basis for down_write_killable()") Link: http://lkml.kernel.org/r/1487981873-12649-1-git-send-email-niklass@axis.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/loadavg: Use {READ,WRITE}_ONCE() for sample windowMatt Fleming
'calc_load_update' is accessed without any kind of locking and there's a clear assumption in the code that only a single value is read or written. Make this explicit by using READ_ONCE() and WRITE_ONCE(), and avoid unintentionally seeing multiple values, or having the load/stores split. Technically the loads in calc_global_*() don't require this since those are the only functions that update 'calc_load_update', but I've added the READ_ONCE() for consistency. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20170217120731.11868-3-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/loadavg: Avoid loadavg spikes caused by delayed NO_HZ accountingMatt Fleming
If we crossed a sample window while in NO_HZ we will add LOAD_FREQ to the pending sample window time on exit, setting the next update not one window into the future, but two. This situation on exiting NO_HZ is described by: this_rq->calc_load_update < jiffies < calc_load_update In this scenario, what we should be doing is: this_rq->calc_load_update = calc_load_update [ next window ] But what we actually do is: this_rq->calc_load_update = calc_load_update + LOAD_FREQ [ next+1 window ] This has the effect of delaying load average updates for potentially up to ~9seconds. This can result in huge spikes in the load average values due to per-cpu uninterruptible task counts being out of sync when accumulated across all CPUs. It's safe to update the per-cpu active count if we wake between sample windows because any load that we left in 'calc_load_idle' will have been zero'd when the idle load was folded in calc_global_load(). This issue is easy to reproduce before, commit 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") just by forking short-lived process pipelines built from ps(1) and grep(1) in a loop. I'm unable to reproduce the spikes after that commit, but the bug still seems to be present from code review. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Fixes: commit 5167e8d ("sched/nohz: Rewrite and fix load-avg computation -- again") Link: http://lkml.kernel.org/r/20170217120731.11868-2-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/deadline: Add missing update_rq_clock() in dl_task_timer()Wanpeng Li
The following warning can be triggered by hot-unplugging the CPU on which an active SCHED_DEADLINE task is running on: ------------[ cut here ]------------ WARNING: CPU: 7 PID: 0 at kernel/sched/sched.h:833 replenish_dl_entity+0x71e/0xc40 rq->clock_update_flags < RQCF_ACT_SKIP CPU: 7 PID: 0 Comm: swapper/7 Tainted: G B 4.11.0-rc1+ #24 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 Call Trace: <IRQ> dump_stack+0x85/0xc4 __warn+0x172/0x1b0 warn_slowpath_fmt+0xb4/0xf0 ? __warn+0x1b0/0x1b0 ? debug_check_no_locks_freed+0x2c0/0x2c0 ? cpudl_set+0x3d/0x2b0 replenish_dl_entity+0x71e/0xc40 enqueue_task_dl+0x2ea/0x12e0 ? dl_task_timer+0x777/0x990 ? __hrtimer_run_queues+0x270/0xa50 dl_task_timer+0x316/0x990 ? enqueue_task_dl+0x12e0/0x12e0 ? enqueue_task_dl+0x12e0/0x12e0 __hrtimer_run_queues+0x270/0xa50 ? hrtimer_cancel+0x20/0x20 ? hrtimer_interrupt+0x119/0x600 hrtimer_interrupt+0x19c/0x600 ? trace_hardirqs_off+0xd/0x10 local_apic_timer_interrupt+0x74/0xe0 smp_apic_timer_interrupt+0x76/0xa0 apic_timer_interrupt+0x93/0xa0 The DL task will be migrated to a suitable later deadline rq once the DL timer fires and currnet rq is offline. The rq clock of the new rq should be updated. This patch fixes it by updating the rq clock after holding the new rq's rq lock. Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1488865888-15894-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16x86/mpx: Make unnecessarily global function staticTobias Klauser
Make the function get_user_bd_entry() static as it is not used outside of arch/x86/mm/mpx.c This fixes a sparse warning. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16Merge branch 'drm-fixes-4.11' of git://people.freedesktop.org/~agd5f/linux ↵Dave Airlie
into drm-fixes A few amd fixes. * 'drm-fixes-4.11' of git://people.freedesktop.org/~agd5f/linux: drm/amd/amdgpu: Fix debugfs reg read/write address width drm/amdgpu/si: add dpm quirk for Oland drm/radeon/si: add dpm quirk for Oland drm: amd: remove broken include path drm/amd/powerplay: fix copy error in smu7_clockpoweragting.c drm/amdgpu: fix parser init error path to avoid crash in parser fini drm/amd/amdgpu: Disable GFX_PG on Carrizo until compute issues solved
2017-03-15Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Four small fixes for this cycle: - followup fix from Neil for a fix that went in before -rc2, ensuring that we always see the full per-task bio_list. - fix for blk-mq-sched from me that ensures that we retain similar direct-to-issue behavior on running the queue. - fix from Sagi fixing a potential NULL pointer dereference in blk-mq on spurious CPU unplug. - a memory leak fix in writeback from Tahsin, fixing a case where device removal of a mounted device can leak a struct wb_writeback_work" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq-sched: don't run the queue async from blk_mq_try_issue_directly() writeback: fix memory leak in wb_queue_work() blk-mq: Fix tagset reinit in the presence of cpu hot-unplug blk: Ensure users for current->bio_list can see the full list.
2017-03-16cpufreq: Fix and clean up show_cpuinfo_cur_freq()Rafael J. Wysocki
There is a missing newline in show_cpuinfo_cur_freq(), so add it, but while at it clean that function up somewhat too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: All applicable <stable@vger.kernel.org>
2017-03-15drm/i915: Only attempt to signal the request once from the interrupt handlerChris Wilson
Check that request has not been signaled before acquiring a reference to the request for signaling later in the interrupt handler. The loading of the cacheline (for request->fence.flags) should be "free" when followed by the locked increment of the request->fence.refcount (which then sets the cacheline to exclusive mode), i.e. the cost of test_bit prior to an atomic_inc should be negligible. This should benefit us when we have a pile of bare breadcrumbs (interrupted execbuf) where we may get interrupts faster than we can get rid of the intel_wait, or if the device is too slow to run the bottom-half between interrupts. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-5-chris@chris-wilson.co.uk
2017-03-15drm/i915/breadcrumbs: Assert that we do not shortcut the current bottom-halfChris Wilson
We need to ensure that we always serialize updates to the bottom-half using the breadcrumbs.irq_lock so that we don't race with a concurrent interrupt handler. This is most important just prior to leaving the waiter (when the intel_wait will be overwritten), so make sure we are not the current bottom-half when skipping the irq locks. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170315210726.12095-4-chris@chris-wilson.co.uk