Add two tracepoints to profile the page defragmentation worker: - xe_bo_defrag_worker: emitted on worker entry and exit with the current defrag list count and the bytes processed in the run. - xe_bo_defrag_one: emitted per BO with the run budget, the prealloc fill ratio (got/want) and the lock-held, lock-wait and prealloc durations, plus the bytes consumed and the result.
These break down the cost of a defrag attempt into its locked vs unlocked phases, making it possible to confirm that the expensive beneficial-order allocation and cpu cache mode change happen outside the BO dma-resv lock and that the residual lock-held time is copy-bound (with the tail dominated by lock-wait behind active rendering). Cc: Carlos Santa <[email protected]> Cc: Ryan Neph <[email protected]> Cc: Christian Koenig <[email protected]> Cc: Huang Rui <[email protected]> Cc: Matthew Auld <[email protected]> Cc: Maarten Lankhorst <[email protected]> Cc: Maxime Ripard <[email protected]> Cc: Thomas Zimmermann <[email protected]> Cc: David Airlie <[email protected]> Cc: Simona Vetter <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Thomas Hellström <[email protected]> Assisted-by: GitHub_Copilot:claude-opus-4.8 Signed-off-by: Matthew Brost <[email protected]> --- drivers/gpu/drm/xe/xe_bo.c | 18 +++++++++- drivers/gpu/drm/xe/xe_trace_bo.h | 59 ++++++++++++++++++++++++++++++++ 2 files changed, 76 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c index 2f014fc9f988..a01004265349 100644 --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -1254,7 +1254,9 @@ static int xe_bo_defrag_one(struct xe_device *xe, struct xe_bo *bo, struct ttm_placement placement; struct ttm_place place; enum ttm_caching tt_caching; - unsigned int order, want = 0; + unsigned int order, want = 0, got = 0; + u64 lock_ns = 0, prealloc_ns = 0, lockwait_ns = 0; + ktime_t t0; int ret = 0; *consumed = 0; @@ -1284,6 +1286,7 @@ static int xe_bo_defrag_one(struct xe_device *xe, struct xe_bo *bo, /* Phase 2: preallocate outside the lock; */ if (want) { + t0 = ktime_get(); ret = ttm_pool_prealloc_fill(pool, tt_caching, &pp, want); if (ret || !pp.count) { ret = ret ?: -ENOMEM; @@ -1291,12 +1294,16 @@ static int xe_bo_defrag_one(struct xe_device *xe, struct xe_bo *bo, XE_GT_STATS_ID_DEFRAG_FAILED_COUNT, 1); goto out_err; } + prealloc_ns = ktime_to_ns(ktime_sub(ktime_get(), t0)); } /* * Phase 3: re-take the lock, re-check, and validate using the prealloc. */ + t0 = ktime_get(); xe_bo_lock(bo, false); + lockwait_ns = ktime_to_ns(ktime_sub(ktime_get(), t0)); + t0 = ktime_get(); if (!xe_bo_needs_defrag(bo)) { xe_bo_defrag_remove(bo); @@ -1350,9 +1357,13 @@ static int xe_bo_defrag_one(struct xe_device *xe, struct xe_bo *bo, unlock: xe_bo_unlock(bo); + lock_ns = ktime_to_ns(ktime_sub(ktime_get(), t0)); + got = pp.used; out_err: ttm_pool_prealloc_fini(pool, &pp); out: + trace_xe_bo_defrag_one(bo, budget, want, got, lock_ns, prealloc_ns, + lockwait_ns, *consumed, ret); return ret; } @@ -1373,6 +1384,9 @@ static void xe_bo_defrag_worker(struct work_struct *w) return; } + trace_xe_bo_defrag_worker(xe, 0, atomic_read(&xe->mem.defrag.count), + true); + /* * Process at most XE_BO_DEFRAG_SIZE_LIMIT bytes of newly (re)allocated * backing per run rather than draining the whole list in one go. Only @@ -1479,6 +1493,8 @@ static void xe_bo_defrag_worker(struct work_struct *w) xe_pm_runtime_put(xe); drm_dev_exit(idx); + trace_xe_bo_defrag_worker(xe, defrag_bytes, + atomic_read(&xe->mem.defrag.count), false); } static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict, diff --git a/drivers/gpu/drm/xe/xe_trace_bo.h b/drivers/gpu/drm/xe/xe_trace_bo.h index 86323cf3be2c..a169a322464b 100644 --- a/drivers/gpu/drm/xe/xe_trace_bo.h +++ b/drivers/gpu/drm/xe/xe_trace_bo.h @@ -85,6 +85,65 @@ TRACE_EVENT(xe_bo_move, __get_str(new_placement_name), __get_str(device_id)) ); +TRACE_EVENT(xe_bo_defrag_worker, + TP_PROTO(struct xe_device *xe, u64 defrag_bytes, int count, + bool enter), + TP_ARGS(xe, defrag_bytes, count, enter), + TP_STRUCT__entry( + __string(dev, dev_name(xe->drm.dev)) + __field(u64, defrag_bytes) + __field(int, count) + __field(bool, enter) + ), + TP_fast_assign( + __assign_str(dev); + __entry->defrag_bytes = defrag_bytes; + __entry->count = count; + __entry->enter = enter; + ), + TP_printk("dev=%s %s defrag_bytes=%llu count=%d", + __get_str(dev), __entry->enter ? "enter" : "exit", + __entry->defrag_bytes, __entry->count) +); + +TRACE_EVENT(xe_bo_defrag_one, + TP_PROTO(struct xe_bo *bo, u64 budget, unsigned int prealloc_want, + unsigned int prealloc_got, u64 lock_ns, u64 prealloc_ns, + u64 lockwait_ns, u64 consumed, int ret), + TP_ARGS(bo, budget, prealloc_want, prealloc_got, lock_ns, + prealloc_ns, lockwait_ns, consumed, ret), + TP_STRUCT__entry( + __string(dev, __dev_name_bo(bo)) + __field(size_t, size) + __field(u64, budget) + __field(unsigned int, prealloc_want) + __field(unsigned int, prealloc_got) + __field(u64, lock_ns) + __field(u64, prealloc_ns) + __field(u64, lockwait_ns) + __field(u64, consumed) + __field(int, ret) + ), + TP_fast_assign( + __assign_str(dev); + __entry->size = xe_bo_size(bo); + __entry->budget = budget; + __entry->prealloc_want = prealloc_want; + __entry->prealloc_got = prealloc_got; + __entry->lock_ns = lock_ns; + __entry->prealloc_ns = prealloc_ns; + __entry->lockwait_ns = lockwait_ns; + __entry->consumed = consumed; + __entry->ret = ret; + ), + TP_printk("dev=%s size=%zu budget=%llu prealloc=%u/%u lock_us=%llu lockwait_us=%llu prealloc_us=%llu consumed=%llu ret=%d", + __get_str(dev), __entry->size, __entry->budget, + __entry->prealloc_got, __entry->prealloc_want, + __entry->lock_ns / 1000, __entry->lockwait_ns / 1000, + __entry->prealloc_ns / 1000, __entry->consumed, + __entry->ret) +); + DECLARE_EVENT_CLASS(xe_vma, TP_PROTO(struct xe_vma *vma), TP_ARGS(vma), -- 2.34.1
