-----Original Message----- From: Intel-xe <intel-xe-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Matthew Brost Sent: Wednesday, July 31, 2024 2:32 PM To: intel-xe@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: maarten.lankhorst@xxxxxxxxxxxxxxx; Vivi, Rodrigo <rodrigo.vivi@xxxxxxxxx> Subject: [PATCH v4 3/3] drm/xe: Faster devcoredump > > The current algorithm to read out devcoredump is O(N*N) where N is the > size of coredump due to usage of the drm_coredump_printer in > xe_devcoredump_read. Switch to a O(N) algorithm which prints the > devcoredump into a readable format in snapshot work and update > xe_devcoredump_read to memcpy from the readable format directly. > > v2: > - Fix double free on devcoredump removal (Testing) > - Set read_data_size after snap work flush > - Adjust remaining in iterator upon realloc (Testing) > - Set read_data upon realloc (Testing) > v3: > - Kernel doc > > Reported-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2408 > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx> > --- > drivers/gpu/drm/xe/xe_devcoredump.c | 112 ++++++++++++++++------ > drivers/gpu/drm/xe/xe_devcoredump_types.h | 4 + > 2 files changed, 85 insertions(+), 31 deletions(-) > > diff --git a/drivers/gpu/drm/xe/xe_devcoredump.c b/drivers/gpu/drm/xe/xe_devcoredump.c > index d8d8ca2c19d3..b802a35c22f2 100644 > --- a/drivers/gpu/drm/xe/xe_devcoredump.c > +++ b/drivers/gpu/drm/xe/xe_devcoredump.c > @@ -66,22 +66,9 @@ static struct xe_guc *exec_queue_to_guc(struct xe_exec_queue *q) > return &q->gt->uc.guc; > } > > -static void xe_devcoredump_deferred_snap_work(struct work_struct *work) > -{ > - struct xe_devcoredump_snapshot *ss = container_of(work, typeof(*ss), work); > - > - /* keep going if fw fails as we still want to save the memory and SW data */ > - if (xe_force_wake_get(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL)) > - xe_gt_info(ss->gt, "failed to get forcewake for coredump capture\n"); > - xe_vm_snapshot_capture_delayed(ss->vm); > - xe_guc_exec_queue_snapshot_capture_delayed(ss->ge); > - xe_force_wake_put(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL); > -} > - > -static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, > - size_t count, void *data, size_t datalen) > +static ssize_t __xe_devcoredump_read(char *buffer, size_t count, > + struct xe_devcoredump *coredump) > { > - struct xe_devcoredump *coredump = data; > struct xe_device *xe; > struct xe_devcoredump_snapshot *ss; > struct drm_printer p; > @@ -89,18 +76,12 @@ static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, > struct timespec64 ts; > int i; > > - if (!coredump) > - return -ENODEV; > - > xe = coredump_to_xe(coredump); > ss = &coredump->snapshot; > > - /* Ensure delayed work is captured before continuing */ > - flush_work(&ss->work); > - > iter.data = buffer; > iter.offset = 0; > - iter.start = offset; > + iter.start = 0; > iter.remain = count; > > p = drm_coredump_printer(&iter); > @@ -131,13 +112,86 @@ static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, > drm_printf(&p, "\n**** VM state ****\n"); > xe_vm_snapshot_print(coredump->snapshot.vm, &p); > > - return count - iter.remain; > + return iter.offset; > +} > + > +static void xe_devcoredump_snapshot_free(struct xe_devcoredump_snapshot *ss) > +{ > + int i; > + > + xe_guc_ct_snapshot_free(ss->ct); > + ss->ct = NULL; > + > + xe_guc_exec_queue_snapshot_free(ss->ge); > + ss->ge = NULL; > + > + xe_sched_job_snapshot_free(ss->job); > + ss->job = NULL; > + > + for (i = 0; i < XE_NUM_HW_ENGINES; i++) > + if (ss->hwe[i]) { > + xe_hw_engine_snapshot_free(ss->hwe[i]); > + ss->hwe[i] = NULL; > + } > + > + xe_vm_snapshot_free(ss->vm); > + ss->vm = NULL; > +} > + > +static void xe_devcoredump_deferred_snap_work(struct work_struct *work) > +{ > + struct xe_devcoredump_snapshot *ss = container_of(work, typeof(*ss), work); > + struct xe_devcoredump *coredump = container_of(ss, typeof(*coredump), snapshot); > + > + /* keep going if fw fails as we still want to save the memory and SW data */ > + if (xe_force_wake_get(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL)) > + xe_gt_info(ss->gt, "failed to get forcewake for coredump capture\n"); > + xe_vm_snapshot_capture_delayed(ss->vm); > + xe_guc_exec_queue_snapshot_capture_delayed(ss->ge); > + xe_force_wake_put(gt_to_fw(ss->gt), XE_FORCEWAKE_ALL); > + > + /* Calculate devcoredump size */ > + ss->read_data_size = __xe_devcoredump_read(NULL, INT_MAX, coredump); > + > + ss->read_data = kvmalloc(ss->read_data_size, GFP_USER); > + if (!ss->read_data) > + return; > + > + __xe_devcoredump_read(ss->read_data, ss->read_data_size, coredump); > + xe_devcoredump_snapshot_free(ss); > +} > + > +static ssize_t xe_devcoredump_read(char *buffer, loff_t offset, > + size_t count, void *data, size_t datalen) > +{ > + struct xe_devcoredump *coredump = data; > + struct xe_devcoredump_snapshot *ss; > + ssize_t byte_copied; > + > + if (!coredump) > + return -ENODEV; > + > + ss = &coredump->snapshot; > + > + /* Ensure delayed work is captured before continuing */ > + flush_work(&ss->work); > + > + if (!ss->read_data) > + return -ENODEV; > + > + if (offset >= ss->read_data_size) > + return 0; > + > + byte_copied = count < ss->read_data_size - offset ? count : > + ss->read_data_size - offset; > + memcpy(buffer, ss->read_data + offset, byte_copied); > + > + return byte_copied; > } > > static void xe_devcoredump_free(void *data) > { > struct xe_devcoredump *coredump = data; > - int i; > > /* Our device is gone. Nothing to do... */ > if (!data || !coredump_to_xe(coredump)) > @@ -145,13 +199,8 @@ static void xe_devcoredump_free(void *data) > > cancel_work_sync(&coredump->snapshot.work); > > - xe_guc_ct_snapshot_free(coredump->snapshot.ct); > - xe_guc_exec_queue_snapshot_free(coredump->snapshot.ge); > - xe_sched_job_snapshot_free(coredump->snapshot.job); > - for (i = 0; i < XE_NUM_HW_ENGINES; i++) > - if (coredump->snapshot.hwe[i]) > - xe_hw_engine_snapshot_free(coredump->snapshot.hwe[i]); > - xe_vm_snapshot_free(coredump->snapshot.vm); > + xe_devcoredump_snapshot_free(&coredump->snapshot); > + kvfree(coredump->snapshot.read_data); > > /* To prevent stale data on next snapshot, clear everything */ > memset(&coredump->snapshot, 0, sizeof(coredump->snapshot)); > @@ -260,4 +309,5 @@ int xe_devcoredump_init(struct xe_device *xe) > { > return devm_add_action_or_reset(xe->drm.dev, xe_driver_devcoredump_fini, &xe->drm); > } > + > #endif > diff --git a/drivers/gpu/drm/xe/xe_devcoredump_types.h b/drivers/gpu/drm/xe/xe_devcoredump_types.h > index 923cdf72a816..0298037edae4 100644 > --- a/drivers/gpu/drm/xe/xe_devcoredump_types.h > +++ b/drivers/gpu/drm/xe/xe_devcoredump_types.h > @@ -46,6 +46,10 @@ struct xe_devcoredump_snapshot { > struct xe_sched_job_snapshot *job; > /** @vm: Snapshot of VM state */ > struct xe_vm_snapshot *vm; > + /** @read_data_size: size of read data */ > + ssize_t read_data_size; > + /** @read_data: Read data */ > + void *read_data; Perhaps the data size and read data can be stapled together under the same struct? struct { ssize_t size; void *data; } read_data; It's not that big of a deal if this is untouched, just something to consider. Reviewed-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx> -Jonathan Cavitt > }; > > /** > -- > 2.34.1 > >
