[PATCH 3/4] drm/xe: Force wedged state and block GT reset upon any GPU hang
Rodrigo Vivi
rodrigo.vivi at intel.com
Thu Apr 4 18:01:07 UTC 2024
On Thu, Apr 04, 2024 at 05:52:15PM +0000, Matthew Brost wrote:
> On Wed, Apr 03, 2024 at 11:07:31AM -0400, Rodrigo Vivi wrote:
> > In many validation situations when debugging GPU Hangs,
> > it is useful to preserve the GT situation from the moment
> > that the timeout occurred.
> >
> > This patch introduces a module parameter that could be used
> > on situations like this.
> >
> > If xe.wedged module parameter is set to 2, Xe will be declared
> > wedged on every single execution timeout (a.k.a. GPU hang) right
> > after devcoredump snapshot capture and without attempting any
> > kind of GT reset and blocking entirely any kind of execution.
> >
> > v2: Really block gt_reset from guc side. (Lucas)
> > s/wedged/busted (Lucas)
> >
> > v3: - s/busted/wedged
> > - Really use global_flags (Dafna)
> > - More robust timeout handling when wedging it.
> >
> > Cc: Dafna Hirschfeld <dhirschfeld at habana.ai>
> > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> > Cc: Alan Previn <alan.previn.teres.alexis at intel.com>
> > Cc: Himanshu Somaiya <himanshu.somaiya at intel.com>
> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > ---
> > drivers/gpu/drm/xe/xe_device.c | 32 +++++++++++++++++++++
> > drivers/gpu/drm/xe/xe_device.h | 15 +---------
> > drivers/gpu/drm/xe/xe_guc_ads.c | 9 +++++-
> > drivers/gpu/drm/xe/xe_guc_submit.c | 46 +++++++++++++++++++++++++-----
> > drivers/gpu/drm/xe/xe_module.c | 5 ++++
> > drivers/gpu/drm/xe/xe_module.h | 1 +
> > 6 files changed, 86 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> > index 7015ef9b00a0..8e380a404a26 100644
> > --- a/drivers/gpu/drm/xe/xe_device.c
> > +++ b/drivers/gpu/drm/xe/xe_device.c
> > @@ -776,3 +776,35 @@ u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64 address)
> > {
> > return address & GENMASK_ULL(xe->info.va_bits - 1, 0);
> > }
> > +
> > +/**
> > + * xe_device_declare_wedged - Declare device wedged
> > + * @xe: xe device instance
> > + *
> > + * This is a final state that can only be cleared with a module
> > + * re-probe (unbind + bind).
> > + * In this state every IOCTL will be blocked so the GT cannot be used.
> > + * In general it will be called upon any critical error such as gt reset
> > + * failure or guc loading failure.
> > + * If xe.wedged module parameter is set to 2, this function will be called
> > + * on every single execution timeout (a.k.a. GPU hang) right after devcoredump
> > + * snapshot capture. In this mode, GT reset won't be attempted so the state of
> > + * the issue is preserved for further debugging.
> > + */
> > +void xe_device_declare_wedged(struct xe_device *xe)
> > +{
> > + if (xe_modparam.wedged_mode == 0)
> > + return;
> > +
> > + if (!atomic_xchg(&xe->wedged, 1)) {
> > + xe->needs_flr_on_fini = true;
> > + drm_err(&xe->drm,
> > + "CRITICAL: Xe has declared device %s as wedged.\n"
> > + "IOCTLs and executions are blocked until device is probed again with unbind and bind operations:\n"
> > + "echo '%s' | sudo tee /sys/bus/pci/drivers/xe/unbind\n"
> > + "echo '%s' | sudo tee /sys/bus/pci/drivers/xe/bind\n"
> > + "Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/xe/kernel/issues/new\n",
> > + dev_name(xe->drm.dev), dev_name(xe->drm.dev),
> > + dev_name(xe->drm.dev));
> > + }
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> > index c532209c5bbd..0fea5c18f76d 100644
> > --- a/drivers/gpu/drm/xe/xe_device.h
> > +++ b/drivers/gpu/drm/xe/xe_device.h
> > @@ -181,19 +181,6 @@ static inline bool xe_device_wedged(struct xe_device *xe)
> > return atomic_read(&xe->wedged);
> > }
> >
> > -static inline void xe_device_declare_wedged(struct xe_device *xe)
> > -{
> > - if (!atomic_xchg(&xe->wedged, 1)) {
> > - xe->needs_flr_on_fini = true;
> > - drm_err(&xe->drm,
> > - "CRITICAL: Xe has declared device %s as wedged.\n"
> > - "IOCTLs and executions are blocked until device is probed again with unbind and bind operations:\n"
> > - "echo '%s' > /sys/bus/pci/drivers/xe/unbind\n"
> > - "echo '%s' > /sys/bus/pci/drivers/xe/bind\n"
> > - "Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/xe/kernel/issues/new\n",
> > - dev_name(xe->drm.dev), dev_name(xe->drm.dev),
> > - dev_name(xe->drm.dev));
> > - }
> > -}
> > +void xe_device_declare_wedged(struct xe_device *xe);
> >
> > #endif
> > diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
> > index e025f3e10c9b..37f30c333c93 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_ads.c
> > +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
> > @@ -18,6 +18,7 @@
> > #include "xe_lrc.h"
> > #include "xe_map.h"
> > #include "xe_mmio.h"
> > +#include "xe_module.h"
> > #include "xe_platform_types.h"
> >
> > /* Slack of a few additional entries per engine */
> > @@ -313,11 +314,17 @@ int xe_guc_ads_init_post_hwconfig(struct xe_guc_ads *ads)
> >
> > static void guc_policies_init(struct xe_guc_ads *ads)
> > {
> > + u32 global_flags = 0;
> > +
> > ads_blob_write(ads, policies.dpc_promote_time,
> > GLOBAL_POLICY_DEFAULT_DPC_PROMOTE_TIME_US);
> > ads_blob_write(ads, policies.max_num_work_items,
> > GLOBAL_POLICY_MAX_NUM_WI);
> > - ads_blob_write(ads, policies.global_flags, 0);
> > +
> > + if (xe_modparam.wedged_mode == 2)
> > + global_flags |= GLOBAL_POLICY_DISABLE_ENGINE_RESET;
> > +
> > + ads_blob_write(ads, policies.global_flags, global_flags);
> > ads_blob_write(ads, policies.is_valid, 1);
> > }
> >
> > diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> > index 0a2a54f69f50..0eba01582f7c 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> > +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> > @@ -35,6 +35,7 @@
> > #include "xe_macros.h"
> > #include "xe_map.h"
> > #include "xe_mocs.h"
> > +#include "xe_module.h"
> > #include "xe_ring_ops_types.h"
> > #include "xe_sched_job.h"
> > #include "xe_trace.h"
> > @@ -900,16 +901,44 @@ static void xe_guc_exec_queue_lr_cleanup(struct work_struct *w)
> > xe_sched_submission_start(sched);
> > }
> >
> > +static void guc_submit_signal_pending_jobs(struct xe_gpu_scheduler *sched,
> > + int err)
> > +{
> > + struct xe_sched_job *job;
> > + int i = 0;
> > +
> > + /* Mark all outstanding jobs as bad, thus completing them */
> > + spin_lock(&sched->base.job_list_lock);
> > + list_for_each_entry(job, &sched->base.pending_list, drm.list)
> > + xe_sched_job_set_error(job, !i++ ? err : -ECANCELED);
> > + spin_unlock(&sched->base.job_list_lock);
> > +}
> > +
> > +static void guc_submit_device_wedged(struct xe_exec_queue *q)
> > +{
> > + struct xe_gpu_scheduler *sched = &q->guc->sched;
> > + struct xe_guc *guc = exec_queue_to_guc(q);
> > +
> > + xe_sched_submission_stop(sched);
> > + xe_guc_exec_queue_trigger_cleanup(q);
> > + guc_submit_signal_pending_jobs(sched, -ETIME);
>
> This will not signal the job that timed out as the job that times out is
> removed from the pending list. In the normal TDR path the pending job is
> added in via xe_sched_add_pending_job call.
yeap, I was kind of wondering that, but I couldn't find a way.
Is there one?
>
> Also with the xe_sched_submission_stop() I don't think free_job() will
> ever get called on the pending jobs. Is that the intent?
Well, that's a good question indeed.
The intent for this aggressive wedged_mode=2 here is to preserve
the most of the memory at the time of the hang happened.
But at the same time, we need to do some clean-ups so we can survive
through the rebind/reprobe and/or module reload.
I'm really open and looking for recommendation and guidance here.
>
>
> > + xe_guc_submit_reset_prepare(guc);
> > + xe_guc_submit_stop(guc);
>
> This also is going to stop all jobs, on all exec queues, from having
> free_job being called.
>
> I guess I am little confused what this function is trying accomplish.
> Can you explain? It would help me review this.
same as above actually.
2 goals: preserve the memory for SV validation teams and survive through
a rebind/reprobe/reload.
if I was not stopping these things here I was getting into some kind
of loops or accesses where our unbind would get badly stuck.
>
> > +}
> > +
> > static enum drm_gpu_sched_stat
> > guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
> > {
> > struct xe_sched_job *job = to_xe_sched_job(drm_job);
> > - struct xe_sched_job *tmp_job;
> > struct xe_exec_queue *q = job->q;
> > struct xe_gpu_scheduler *sched = &q->guc->sched;
> > struct xe_device *xe = guc_to_xe(exec_queue_to_guc(q));
> > int err = -ETIME;
> > - int i = 0;
> > +
> > + if (xe_device_wedged(xe)) {
> > + guc_submit_device_wedged(q);
> > + return DRM_GPU_SCHED_STAT_ENODEV;
> > + }
> >
> > /*
> > * TDR has fired before free job worker. Common if exec queue
> > @@ -933,6 +962,12 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
> >
> > trace_xe_sched_job_timedout(job);
> >
> > + if (xe_modparam.wedged_mode == 2) {
> > + xe_device_declare_wedged(xe);
> > + guc_submit_device_wedged(q);
> > + return DRM_GPU_SCHED_STAT_ENODEV;
> > + }
> > +
> > /* Kill the run_job entry point */
> > xe_sched_submission_stop(sched);
> >
> > @@ -994,13 +1029,10 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
> > */
> > xe_sched_add_pending_job(sched, job);
> > xe_sched_submission_start(sched);
> > +
>
> Nit: Looks unrelated.
>
> Matt
>
> > xe_guc_exec_queue_trigger_cleanup(q);
> >
> > - /* Mark all outstanding jobs as bad, thus completing them */
> > - spin_lock(&sched->base.job_list_lock);
> > - list_for_each_entry(tmp_job, &sched->base.pending_list, drm.list)
> > - xe_sched_job_set_error(tmp_job, !i++ ? err : -ECANCELED);
> > - spin_unlock(&sched->base.job_list_lock);
> > + guc_submit_signal_pending_jobs(sched, err);
> >
> > /* Start fence signaling */
> > xe_hw_fence_irq_start(q->fence_irq);
> > diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
> > index 110b69864656..5e023df0bea9 100644
> > --- a/drivers/gpu/drm/xe/xe_module.c
> > +++ b/drivers/gpu/drm/xe/xe_module.c
> > @@ -17,6 +17,7 @@ struct xe_modparam xe_modparam = {
> > .enable_display = true,
> > .guc_log_level = 5,
> > .force_probe = CONFIG_DRM_XE_FORCE_PROBE,
> > + .wedged_mode = 1,
> > /* the rest are 0 by default */
> > };
> >
> > @@ -48,6 +49,10 @@ module_param_named_unsafe(force_probe, xe_modparam.force_probe, charp, 0400);
> > MODULE_PARM_DESC(force_probe,
> > "Force probe options for specified devices. See CONFIG_DRM_XE_FORCE_PROBE for details.");
> >
> > +module_param_named_unsafe(wedged_mode, xe_modparam.wedged_mode, int, 0600);
> > +MODULE_PARM_DESC(wedged_mode,
> > + "Module's default policy for the wedged mode - 0=never, 1=upon-critical-errors[default], 2=upon-any-hang");
> > +
> > struct init_funcs {
> > int (*init)(void);
> > void (*exit)(void);
> > diff --git a/drivers/gpu/drm/xe/xe_module.h b/drivers/gpu/drm/xe/xe_module.h
> > index 88ef0e8b2bfd..bc6f370c9a8e 100644
> > --- a/drivers/gpu/drm/xe/xe_module.h
> > +++ b/drivers/gpu/drm/xe/xe_module.h
> > @@ -18,6 +18,7 @@ struct xe_modparam {
> > char *huc_firmware_path;
> > char *gsc_firmware_path;
> > char *force_probe;
> > + int wedged_mode;
> > };
> >
> > extern struct xe_modparam xe_modparam;
> > --
> > 2.44.0
> >
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