6.18-stable review patch. If anyone has any objections, please let me know.
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From: Matthew Brost matthew.brost@intel.com
commit 80f9c601d9c4d26f00356c0a9c461650e7089273 upstream.
msleep is not very accurate in terms of how long it actually sleeps, whereas usleep_range is precise. Replace the timeslice sleep for long-running workloads with the more accurate usleep_range to avoid jitter if the sleep period is less than 20ms.
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Cc: stable@vger.kernel.org Signed-off-by: Matthew Brost matthew.brost@intel.com Reviewed-by: Thomas Hellström thomas.hellstrom@linux.intel.com Link: https://patch.msgid.link/20251212182847.1683222-3-matthew.brost@intel.com (cherry picked from commit ca415c4d4c17ad676a2c8981e1fcc432221dce79) Signed-off-by: Thomas Hellström thomas.hellstrom@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/xe/xe_guc_submit.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/xe/xe_guc_submit.c +++ b/drivers/gpu/drm/xe/xe_guc_submit.c @@ -670,6 +670,24 @@ static u32 wq_space_until_wrap(struct xe return (WQ_SIZE - q->guc->wqi_tail); }
+static inline void relaxed_ms_sleep(unsigned int delay_ms) +{ + unsigned long min_us, max_us; + + if (!delay_ms) + return; + + if (delay_ms > 20) { + msleep(delay_ms); + return; + } + + min_us = mul_u32_u32(delay_ms, 1000); + max_us = min_us + 500; + + usleep_range(min_us, max_us); +} + static int wq_wait_for_space(struct xe_exec_queue *q, u32 wqi_size) { struct xe_guc *guc = exec_queue_to_guc(q); @@ -1559,7 +1577,7 @@ static void __guc_exec_queue_process_msg since_resume_ms;
if (wait_ms > 0 && q->guc->resume_time) - msleep(wait_ms); + relaxed_ms_sleep(wait_ms);
set_exec_queue_suspended(q); disable_scheduling(q, false);