| Message ID | 20201126211453.15461-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/display: Record the plane update times for debugging | expand |
Hi Chris,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-tip/drm-tip v5.10-rc5 next-20201126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Chris-Wilson/drm-i915-display-Record-the-plane-update-times-for-debugging/20201127-052128
base: git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/7507dad86ddaa800a17665609a0171e9b958b451
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Chris-Wilson/drm-i915-display-Record-the-plane-update-times-for-debugging/20201127-052128
git checkout 7507dad86ddaa800a17665609a0171e9b958b451
# save the attached .config to linux build tree
make W=1 ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/drm/drm_mm.h:49,
from include/drm/drm_vma_manager.h:26,
from include/drm/drm_gem.h:40,
from drivers/gpu/drm/i915/i915_drv.h:55,
from drivers/gpu/drm/i915/display/intel_sprite.c:42:
drivers/gpu/drm/i915/display/intel_sprite.c: In function 'dbg_vblank_evade':
include/drm/drm_print.h:450:19: error: request for member 'dev' in something not a structure or union
450 | drm_dev_dbg((drm)->dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
| ^~
drivers/gpu/drm/i915/display/intel_sprite.c:201:3: note: in expansion of macro 'drm_dbg_kms'
201 | drm_dbg_kms("Atomic update on pipe (%c) took %lld us, max time under evasion is %u us\n",
| ^~~~~~~~~~~
>> drivers/gpu/drm/i915/display/intel_display.h:96:27: warning: passing argument 3 of 'drm_dev_dbg' makes pointer from integer without a cast [-Wint-conversion]
96 | #define pipe_name(p) ((p) + 'A')
| ~~~~~^~~~~~
| |
| int
include/drm/drm_print.h:450:38: note: in definition of macro 'drm_dbg_kms'
450 | drm_dev_dbg((drm)->dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
| ^~~
drivers/gpu/drm/i915/display/intel_sprite.c:202:8: note: in expansion of macro 'pipe_name'
202 | pipe_name(crtc->pipe),
| ^~~~~~~~~
include/drm/drm_print.h:338:16: note: expected 'const char *' but argument is of type 'int'
338 | const char *format, ...);
| ~~~~~~~~~~~~^~~~~~
vim +/drm_dev_dbg +96 drivers/gpu/drm/i915/display/intel_display.h
09a28bd9e8024d1 drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 95
09a28bd9e8024d1 drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 @96 #define pipe_name(p) ((p) + 'A')
09a28bd9e8024d1 drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 97
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Hi Chris,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-tip/drm-tip v5.10-rc5 next-20201126]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Chris-Wilson/drm-i915-display-Record-the-plane-update-times-for-debugging/20201127-052128
base: git://anongit.freedesktop.org/drm-intel for-linux-next
config: i386-randconfig-a004-20201127 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
# https://github.com/0day-ci/linux/commit/7507dad86ddaa800a17665609a0171e9b958b451
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Chris-Wilson/drm-i915-display-Record-the-plane-update-times-for-debugging/20201127-052128
git checkout 7507dad86ddaa800a17665609a0171e9b958b451
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from include/drm/drm_mm.h:49,
from include/drm/drm_vma_manager.h:26,
from include/drm/drm_gem.h:40,
from drivers/gpu/drm/i915/i915_drv.h:55,
from drivers/gpu/drm/i915/display/intel_sprite.c:42:
drivers/gpu/drm/i915/display/intel_sprite.c: In function 'dbg_vblank_evade':
include/drm/drm_print.h:450:19: error: request for member 'dev' in something not a structure or union
450 | drm_dev_dbg((drm)->dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
| ^~
drivers/gpu/drm/i915/display/intel_sprite.c:201:3: note: in expansion of macro 'drm_dbg_kms'
201 | drm_dbg_kms("Atomic update on pipe (%c) took %lld us, max time under evasion is %u us\n",
| ^~~~~~~~~~~
>> drivers/gpu/drm/i915/display/intel_display.h:96:27: error: passing argument 3 of 'drm_dev_dbg' makes pointer from integer without a cast [-Werror=int-conversion]
96 | #define pipe_name(p) ((p) + 'A')
| ~~~~~^~~~~~
| |
| int
include/drm/drm_print.h:450:38: note: in definition of macro 'drm_dbg_kms'
450 | drm_dev_dbg((drm)->dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
| ^~~
drivers/gpu/drm/i915/display/intel_sprite.c:202:8: note: in expansion of macro 'pipe_name'
202 | pipe_name(crtc->pipe),
| ^~~~~~~~~
include/drm/drm_print.h:338:16: note: expected 'const char *' but argument is of type 'int'
338 | const char *format, ...);
| ~~~~~~~~~~~~^~~~~~
cc1: all warnings being treated as errors
vim +/drm_dev_dbg +96 drivers/gpu/drm/i915/display/intel_display.h
09a28bd9e8024d drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 95
09a28bd9e8024d drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 @96 #define pipe_name(p) ((p) + 'A')
09a28bd9e8024d drivers/gpu/drm/i915/intel_display.h Michal Wajdeczko 2017-12-21 97
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c index ca41e8c00ad7..fd1a97b9e653 100644 --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c @@ -18,6 +18,7 @@ #include "intel_pm.h" #include "intel_psr.h" #include "intel_sideband.h" +#include "intel_sprite.h" static inline struct drm_i915_private *node_to_i915(struct drm_info_node *node) { @@ -865,6 +866,51 @@ static void intel_scaler_info(struct seq_file *m, struct intel_crtc *crtc) } } +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE) +static void crtc_vblank_info(struct seq_file *m, struct intel_crtc *crtc) +{ + char buf[ARRAY_SIZE(crtc->debug.vbl_times) + 1] = {}; + int h, row, max; + u64 count; + + max = 0; + count = 0; + for (h = 0; h < ARRAY_SIZE(crtc->debug.vbl_times); h++) { + if (crtc->debug.vbl_times[h] > max) + max = crtc->debug.vbl_times[h]; + count += crtc->debug.vbl_times[h]; + } + seq_printf(m, "\tUpdates: %llu\n", count); + if (!count) + return; + + memset(buf, '-', sizeof(buf) - 1); + seq_printf(m, "\t |%s|\n", buf); + + for (row = ilog2(max) - 1; row; row--) { + memset(buf, ' ', sizeof(buf) - 1); + for (h = 0; h < ARRAY_SIZE(crtc->debug.vbl_times); h++) { + if (ilog2(crtc->debug.vbl_times[h]) >= row) + buf[h] = '*'; + } + seq_printf(m, "\t |%s|\n", buf); + } + + memset(buf, '-', sizeof(buf) - 1); + seq_printf(m, "\t |%s|\n", buf); + seq_printf(m, "\t 1us (log) 1ms\n"); + + seq_printf(m, "\tMin update: %lluns\n", crtc->debug.min_vbl_time); + seq_printf(m, "\tMax update: %lluns\n", crtc->debug.max_vbl_time); + seq_printf(m, "\tAverage update: %lluns\n", + div64_u64(crtc->debug.sum_vbl_time, count)); + seq_printf(m, "\tOverruns > %uus: %lu\n", + VBLANK_EVASION_TIME_US, crtc->debug.over_vbl_time); +} +#else +static void crtc_vblank_info(struct seq_file *m, struct intel_crtc *crtc) {} +#endif + static void intel_crtc_info(struct seq_file *m, struct intel_crtc *crtc) { struct drm_i915_private *dev_priv = node_to_i915(m->private); @@ -907,6 +953,8 @@ static void intel_crtc_info(struct seq_file *m, struct intel_crtc *crtc) seq_printf(m, "\tunderrun reporting: cpu=%s pch=%s\n", yesno(!crtc->cpu_fifo_underrun_disabled), yesno(!crtc->pch_fifo_underrun_disabled)); + + crtc_vblank_info(m, crtc); } static int i915_display_info(struct seq_file *m, void *unused) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index ce82d654d0f2..eef3b1fa7e92 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1186,6 +1186,13 @@ struct intel_crtc { ktime_t start_vbl_time; int min_vbl, max_vbl; int scanline_start; +#ifdef CONFIG_DRM_I915_DEBUG_VBLANK_EVADE + u64 min_vbl_time; + u64 max_vbl_time; + u64 sum_vbl_time; + unsigned long over_vbl_time; + unsigned int vbl_times[21]; /* [1us, 1ms] */ +#endif } debug; /* scalers available on this crtc */ diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c index 019a2d6d807a..f6e1861f3c31 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -61,14 +61,6 @@ int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode, 1000 * adjusted_mode->crtc_htotal); } -/* FIXME: We should instead only take spinlocks once for the entire update - * instead of once per mmio. */ -#if IS_ENABLED(CONFIG_PROVE_LOCKING) -#define VBLANK_EVASION_TIME_US 250 -#else -#define VBLANK_EVASION_TIME_US 100 -#endif - /** * intel_pipe_update_start() - start update of a set of display registers * @new_crtc_state: the new crtc state @@ -187,6 +179,36 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state) local_irq_disable(); } +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE) +static void dbg_vblank_evade(struct intel_crtc *crtc, ktime_t end) +{ + u64 delta = ktime_to_ns(ktime_sub(end, crtc->debug.start_vbl_time)); + unsigned int h; + + h = ilog2(delta >> 9); + if (h >= ARRAY_SIZE(crtc->debug.vbl_times)) + h = ARRAY_SIZE(crtc->debug.vbl_times) - 1; + crtc->debug.vbl_times[h]++; + + crtc->debug.sum_vbl_time += delta; + if (!crtc->debug.min_vbl_time || + delta < crtc->debug.min_vbl_time) + crtc->debug.min_vbl_time = delta; + if (delta > crtc->debug.max_vbl_time) + crtc->debug.max_vbl_time = delta; + + if (delta > 1000 * VBLANK_EVASION_TIME_US) { + drm_dbg_kms("Atomic update on pipe (%c) took %lld us, max time under evasion is %u us\n", + pipe_name(crtc->pipe), + div_u64(delta, 1000), + VBLANK_EVASION_TIME_US); + crtc->debug.over_vbl_time++; + } +} +#else +static void dbg_vblank_evade(struct intel_crtc *crtc, ktime_t end) {} +#endif + /** * intel_pipe_update_end() - end update of a set of display registers * @new_crtc_state: the new crtc state @@ -249,15 +271,8 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state) crtc->debug.min_vbl, crtc->debug.max_vbl, crtc->debug.scanline_start, scanline_end); } -#ifdef CONFIG_DRM_I915_DEBUG_VBLANK_EVADE - else if (ktime_us_delta(end_vbl_time, crtc->debug.start_vbl_time) > - VBLANK_EVASION_TIME_US) - drm_warn(&dev_priv->drm, - "Atomic update on pipe (%c) took %lld us, max time under evasion is %u us\n", - pipe_name(pipe), - ktime_us_delta(end_vbl_time, crtc->debug.start_vbl_time), - VBLANK_EVASION_TIME_US); -#endif + + dbg_vblank_evade(crtc, end_vbl_time); } int intel_plane_check_stride(const struct intel_plane_state *plane_state) diff --git a/drivers/gpu/drm/i915/display/intel_sprite.h b/drivers/gpu/drm/i915/display/intel_sprite.h index cd2104ba1ca1..76126dd8d584 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.h +++ b/drivers/gpu/drm/i915/display/intel_sprite.h @@ -17,6 +17,16 @@ struct drm_i915_private; struct intel_crtc_state; struct intel_plane_state; +/* + * FIXME: We should instead only take spinlocks once for the entire update + * instead of once per mmio. + */ +#if IS_ENABLED(CONFIG_PROVE_LOCKING) +#define VBLANK_EVASION_TIME_US 250 +#else +#define VBLANK_EVASION_TIME_US 100 +#endif + int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode, int usecs); struct intel_plane *intel_sprite_plane_create(struct drm_i915_private *dev_priv,
Since we try and estimate how long we require to update the registers to perform a plane update, it is of vital importance that we measure the distribution of plane updates to better guide our estimate. If we underestimate how long it takes to perform the plane update, we may slip into the next scanout frame causing a tear. If we overestimate, we may unnecessarily delay the update to the next frame, causing visible jitter. Replace the warning that we exceed some arbitrary threshold for the vblank update with a histogram for debugfs. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1982 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> --- .../drm/i915/display/intel_display_debugfs.c | 48 ++++++++++++++++++ .../drm/i915/display/intel_display_types.h | 7 +++ drivers/gpu/drm/i915/display/intel_sprite.c | 49 ++++++++++++------- drivers/gpu/drm/i915/display/intel_sprite.h | 10 ++++ 4 files changed, 97 insertions(+), 17 deletions(-)