On Thu, Jan 16, 2025 at 9:47 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote: > > Hi Tzung-Bi, > > First of all, thanks for the patch! > > On Thu, Jan 09, 2025 at 05:35:04AM +0000, Tzung-Bi Shih wrote: > > When compiling allmodconfig (CONFIG_WERROR=y) with clang-19, see the > > following errors: > > > > .../display/dc/dml2/display_mode_core.c:6268:13: warning: stack frame size (3128) exceeds limit (3072) in 'dml_prefetch_check' [-Wframe-larger-than] > > .../display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c:7236:13: warning: stack frame size (3256) exceeds limit (3072) in 'dml_core_mode_support' [-Wframe-larger-than] > > > > Mark static functions called by dml_prefetch_check() and > > dml_core_mode_support() noinline_for_stack to avoid them become huge > > functions and thus exceed the frame size limit. > > So I fixed these particular instances by hiding them when certain > sanitizers are enabled: > > https://gitlab.freedesktop.org/agd5f/linux/-/commit/e4479aecf6581af81bc0908575447878d2a07e01 > > However, there are still reports of the regular 2048 limit being hit > with certain configurations such as LTO (the issue number is somewhat > funny given the situation): > > https://github.com/ClangBuiltLinux/linux/issues/2048 > > So I think it would be a good idea for the AMD folks to consider > applying this patch as well. Sure. Applied. Thanks. Alex > > > A way to reproduce: > > $ git checkout next-20250107 > > $ mkdir build_dir > > $ export PATH=/tmp/llvm-19.1.6-x86_64/bin:$PATH > > $ make LLVM=1 O=build_dir allmodconfig > > $ make LLVM=1 O=build_dir drivers/gpu/drm/ -j > > > > The way how it chose static functions to mark: > > [0] Unset CONFIG_WERROR in build_dir/.config. > > To get display_mode_core.o without errors. > > > > [1] Get a function list called by dml_prefetch_check(). > > $ sed -n '6268,6711p' drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c \ > > | sed -n -r 's/.*\W(\w+)\(.*/\1/p' | sort -u >/tmp/syms > > > > [2] Get the non-inline function list. > > Objdump won't show the symbols if they are inline functions. > > > > $ make LLVM=1 O=build_dir drivers/gpu/drm/ -j > > $ objdump -d build_dir/.../display_mode_core.o | \ > > ./scripts/checkstack.pl x86_64 0 | \ > > grep -f /tmp/syms | cut -d' ' -f2- >/tmp/orig > > > > [3] Get the full function list. > > Append "-fno-inline" to `CFLAGS_.../display_mode_core.o` in > > drivers/gpu/drm/amd/display/dc/dml2/Makefile. > > > > $ make LLVM=1 O=build_dir drivers/gpu/drm/ -j > > $ objdump -d build_dir/.../display_mode_core.o | \ > > ./scripts/checkstack.pl x86_64 0 | \ > > grep -f /tmp/syms | cut -d' ' -f2- >/tmp/noinline > > > > [4] Get the inline function list. > > If a symbol only in /tmp/noinline but not in /tmp/orig, it is a good > > candidate to mark noinline. > > > > $ diff /tmp/orig /tmp/noinline > > > > Chosen functions and their stack sizes: > > CalculateBandwidthAvailableForImmediateFlip [display_mode_core.o]:144 > > CalculateExtraLatency [display_mode_core.o]:176 > > CalculateTWait [display_mode_core.o]:64 > > CalculateVActiveBandwithSupport [display_mode_core.o]:112 > > set_calculate_prefetch_schedule_params [display_mode_core.o]:48 > > > > CheckGlobalPrefetchAdmissibility [dml2_core_dcn4_calcs.o]:544 > > calculate_bandwidth_available [dml2_core_dcn4_calcs.o]:320 > > calculate_vactive_det_fill_latency [dml2_core_dcn4_calcs.o]:272 > > CalculateDCFCLKDeepSleep [dml2_core_dcn4_calcs.o]:208 > > CalculateODMMode [dml2_core_dcn4_calcs.o]:208 > > CalculateOutputLink [dml2_core_dcn4_calcs.o]:176 > > > > Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx> > > --- > > .../gpu/drm/amd/display/dc/dml2/display_mode_core.c | 12 ++++++------ > > .../dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c | 12 ++++++------ > > 2 files changed, 12 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c > > index 35bc917631ae..84a2de9a76d4 100644 > > --- a/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c > > +++ b/drivers/gpu/drm/amd/display/dc/dml2/display_mode_core.c > > @@ -1736,7 +1736,7 @@ static void CalculateBytePerPixelAndBlockSizes( > > #endif > > } // CalculateBytePerPixelAndBlockSizes > > > > -static dml_float_t CalculateTWait( > > +static noinline_for_stack dml_float_t CalculateTWait( > > dml_uint_t PrefetchMode, > > enum dml_use_mall_for_pstate_change_mode UseMALLForPStateChange, > > dml_bool_t SynchronizeDRRDisplaysForUCLKPStateChangeFinal, > > @@ -4458,7 +4458,7 @@ static void CalculateSwathWidth( > > } > > } // CalculateSwathWidth > > > > -static dml_float_t CalculateExtraLatency( > > +static noinline_for_stack dml_float_t CalculateExtraLatency( > > dml_uint_t RoundTripPingLatencyCycles, > > dml_uint_t ReorderingBytes, > > dml_float_t DCFCLK, > > @@ -5915,7 +5915,7 @@ static dml_uint_t DSCDelayRequirement( > > return DSCDelayRequirement_val; > > } > > > > -static dml_bool_t CalculateVActiveBandwithSupport(dml_uint_t NumberOfActiveSurfaces, > > +static noinline_for_stack dml_bool_t CalculateVActiveBandwithSupport(dml_uint_t NumberOfActiveSurfaces, > > dml_float_t ReturnBW, > > dml_bool_t NotUrgentLatencyHiding[], > > dml_float_t ReadBandwidthLuma[], > > @@ -6019,7 +6019,7 @@ static void CalculatePrefetchBandwithSupport( > > #endif > > } > > > > -static dml_float_t CalculateBandwidthAvailableForImmediateFlip( > > +static noinline_for_stack dml_float_t CalculateBandwidthAvailableForImmediateFlip( > > dml_uint_t NumberOfActiveSurfaces, > > dml_float_t ReturnBW, > > dml_float_t ReadBandwidthLuma[], > > @@ -6213,7 +6213,7 @@ static dml_uint_t CalculateMaxVStartup( > > return max_vstartup_lines; > > } > > > > -static void set_calculate_prefetch_schedule_params(struct display_mode_lib_st *mode_lib, > > +static noinline_for_stack void set_calculate_prefetch_schedule_params(struct display_mode_lib_st *mode_lib, > > struct CalculatePrefetchSchedule_params_st *CalculatePrefetchSchedule_params, > > dml_uint_t j, > > dml_uint_t k) > > @@ -6265,7 +6265,7 @@ static void set_calculate_prefetch_schedule_params(struct display_mode_lib_st *m > > CalculatePrefetchSchedule_params->Tno_bw = &mode_lib->ms.Tno_bw[k]; > > } > > > > -static void dml_prefetch_check(struct display_mode_lib_st *mode_lib) > > +static noinline_for_stack void dml_prefetch_check(struct display_mode_lib_st *mode_lib) > > { > > struct dml_core_mode_support_locals_st *s = &mode_lib->scratch.dml_core_mode_support_locals; > > struct CalculatePrefetchSchedule_params_st *CalculatePrefetchSchedule_params = &mode_lib->scratch.CalculatePrefetchSchedule_params; > > diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c > > index b9ec243cf9ba..7fffca67ca9d 100644 > > --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c > > +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c > > @@ -2778,7 +2778,7 @@ static double dml_get_return_bandwidth_available( > > return return_bw_mbps; > > } > > > > -static void calculate_bandwidth_available( > > +static noinline_for_stack void calculate_bandwidth_available( > > double avg_bandwidth_available_min[dml2_core_internal_soc_state_max], > > double avg_bandwidth_available[dml2_core_internal_soc_state_max][dml2_core_internal_bw_max], > > double urg_bandwidth_available_min[dml2_core_internal_soc_state_max], // min between SDP and DRAM > > @@ -3531,7 +3531,7 @@ static void CalculateUrgentBurstFactor( > > > > } > > > > -static void CalculateDCFCLKDeepSleep( > > +static noinline_for_stack void CalculateDCFCLKDeepSleep( > > const struct dml2_display_cfg *display_cfg, > > unsigned int NumberOfActiveSurfaces, > > unsigned int BytePerPixelY[], > > @@ -4076,7 +4076,7 @@ static bool ValidateODMMode(enum dml2_odm_mode ODMMode, > > return true; > > } > > > > -static void CalculateODMMode( > > +static noinline_for_stack void CalculateODMMode( > > unsigned int MaximumPixelsPerLinePerDSCUnit, > > unsigned int HActive, > > enum dml2_output_format_class OutFormat, > > @@ -4173,7 +4173,7 @@ static void CalculateODMMode( > > #endif > > } > > > > -static void CalculateOutputLink( > > +static noinline_for_stack void CalculateOutputLink( > > struct dml2_core_internal_scratch *s, > > double PHYCLK, > > double PHYCLKD18, > > @@ -5928,7 +5928,7 @@ static double calculate_impacted_Tsw(unsigned int exclude_plane_idx, unsigned in > > } > > > > // a global check against the aggregate effect of the per plane prefetch schedule > > -static bool CheckGlobalPrefetchAdmissibility(struct dml2_core_internal_scratch *scratch, > > +static noinline_for_stack bool CheckGlobalPrefetchAdmissibility(struct dml2_core_internal_scratch *scratch, > > struct dml2_core_calcs_CheckGlobalPrefetchAdmissibility_params *p) > > { > > struct dml2_core_calcs_CheckGlobalPrefetchAdmissibility_locals *s = &scratch->CheckGlobalPrefetchAdmissibility_locals; > > @@ -6941,7 +6941,7 @@ static void calculate_bytes_to_fetch_required_to_hide_latency( > > } > > } > > > > -static void calculate_vactive_det_fill_latency( > > +static noinline_for_stack void calculate_vactive_det_fill_latency( > > const struct dml2_display_cfg *display_cfg, > > unsigned int num_active_planes, > > unsigned int bytes_required_l[], > > -- > > 2.47.1.613.gc27f4b7a9f-goog > >
