Hi Steven, Thanks for the feedback! On Thu, Dec 12, 2019 at 10:20:50PM -0500, Steven Rostedt wrote: > On Thu, 12 Dec 2019 15:32:35 -0500 > Sean Paul <sean@xxxxxxxxxx> wrote: > > > > > What about trace_printk()? It doesn't give us the control we get from using > > tracepoints and it's not meant to be left sprinkled around in code. > > Not to mention that trace_printk() is not for production use (only for > developers debugging purposes). > Yep, I'll clarify this in the next version. > > > > Cc: David Airlie <airlied@xxxxxxxxx> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Cc: Pekka Paalanen <ppaalanen@xxxxxxxxx> > > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> > > Cc: Rob Clark <robdclark@xxxxxxxxx> > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx> > > Link: https://patchwork.freedesktop.org/patch/msgid/20191010204823.195540-1-sean@xxxxxxxxxx #v1 > > > > Changes in v2: > > - Went with a completely different approach: https://lists.freedesktop.org/archives/dri-devel/2019-November/243230.html > > > > Changes in v3: > > - Changed commit message to be a bit less RFC-y > > - Make class_drm_category_log an actual trace class > > --- > > > > Even though we don't want it to be, this is UAPI. So here's some userspace > > code which uses it: > > https://chromium-review.googlesource.com/c/chromiumos/platform2/+/1965562 > > > > > > drivers/gpu/drm/drm_print.c | 143 ++++++++++++++++++++++++++----- > > include/trace/events/drm_print.h | 116 +++++++++++++++++++++++++ > > 2 files changed, 239 insertions(+), 20 deletions(-) > > create mode 100644 include/trace/events/drm_print.h > > > > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c > > index 9a25d73c155c..f591292811aa 100644 > > --- a/drivers/gpu/drm/drm_print.c > > +++ b/drivers/gpu/drm/drm_print.c > > @@ -27,11 +27,15 @@ > > > > #include <stdarg.h> > > > > +#include <linux/bitops.h> > > #include <linux/io.h> > > #include <linux/moduleparam.h> > > #include <linux/seq_file.h> > > #include <linux/slab.h> > > > > +#define CREATE_TRACE_POINTS > > +#include <trace/events/drm_print.h> > > + > > #include <drm/drm.h> > > #include <drm/drm_drv.h> > > #include <drm/drm_print.h> > > @@ -241,10 +245,10 @@ void drm_dev_printk(const struct device *dev, const char *level, > > struct va_format vaf; > > va_list args; > > > > - va_start(args, format); > > vaf.fmt = format; > > vaf.va = &args; > > > > + va_start(args, format); > > if (dev) > > dev_printk(level, dev, "[" DRM_NAME ":%ps] %pV", > > __builtin_return_address(0), &vaf); > > @@ -253,49 +257,145 @@ void drm_dev_printk(const struct device *dev, const char *level, > > level, __builtin_return_address(0), &vaf); > > > > va_end(args); > > + > > + va_start(args, format); > > + trace_drm_log(level, dev, &vaf); > > + va_end(args); > > } > > EXPORT_SYMBOL(drm_dev_printk); > > > > +static unsigned int drm_trace_enabled(unsigned int category) > > +{ > > + unsigned int bit; > > + > > + for_each_set_bit(bit, (unsigned long*)&category, sizeof(category) * 8) { > > + switch (BIT(bit)) { > > + case DRM_UT_NONE: > > + return trace_drm_dbg_none_enabled(); > > + case DRM_UT_CORE: > > + return trace_drm_dbg_core_enabled(); > > + case DRM_UT_DRIVER: > > + return trace_drm_dbg_driver_enabled(); > > + case DRM_UT_KMS: > > + return trace_drm_dbg_kms_enabled(); > > + case DRM_UT_PRIME: > > + return trace_drm_dbg_prime_enabled(); > > + case DRM_UT_ATOMIC: > > + return trace_drm_dbg_atomic_enabled(); > > + case DRM_UT_VBL: > > + return trace_drm_dbg_vbl_enabled(); > > + case DRM_UT_STATE: > > + return trace_drm_dbg_state_enabled(); > > + case DRM_UT_LEASE: > > + return trace_drm_dbg_lease_enabled(); > > + case DRM_UT_DP: > > + return trace_drm_dbg_dp_enabled(); > > + default: > > + return trace_drm_dbg_unknown_enabled(); > > + } > > Why this double loop? > category is technically a bitfield, but only 1 bit is ever set (grander plans when it was created, I suppose). As Jani mentions, it's being changed to an enum, so we won't need this loop. > > + } > > + return false; > > +} > > + > > +static void drm_do_trace(const struct device *dev, unsigned int category, > > + struct va_format *vaf) > > +{ > > + WARN_ON(hweight32(category) > 1); > > + > > + switch (category) { > > + case DRM_UT_NONE: > > + trace_drm_dbg_none(dev, vaf); > > + break; > > + case DRM_UT_CORE: > > + trace_drm_dbg_core(dev, vaf); > > + break; > > + case DRM_UT_DRIVER: > > + trace_drm_dbg_driver(dev, vaf); > > + break; > > + case DRM_UT_KMS: > > + trace_drm_dbg_kms(dev, vaf); > > + break; > > + case DRM_UT_PRIME: > > + trace_drm_dbg_prime(dev, vaf); > > + break; > > + case DRM_UT_ATOMIC: > > + trace_drm_dbg_atomic(dev, vaf); > > + break; > > + case DRM_UT_VBL: > > + trace_drm_dbg_vbl(dev, vaf); > > + break; > > + case DRM_UT_STATE: > > + trace_drm_dbg_state(dev, vaf); > > + break; > > + case DRM_UT_LEASE: > > + trace_drm_dbg_lease(dev, vaf); > > + break; > > + case DRM_UT_DP: > > + trace_drm_dbg_dp(dev, vaf); > > + break; > > + default: > > + trace_drm_dbg_unknown(dev, vaf); > > + break; > > Why is there a separate trace event for each of these? > To make it easier on userspace to enable just a single drm category. > > + } > > +} > > + > > void drm_dev_dbg(const struct device *dev, unsigned int category, > > const char *format, ...) > > { > > struct va_format vaf; > > + unsigned int bit; > > va_list args; > > > > - if (!drm_debug_enabled(category)) > > - return; > > - > > - va_start(args, format); > > vaf.fmt = format; > > vaf.va = &args; > > > > - if (dev) > > - dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV", > > - __builtin_return_address(0), &vaf); > > - else > > - printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > > - __builtin_return_address(0), &vaf); > > + if (drm_debug_enabled(category)) { > > + va_start(args, format); > > + if (dev) > > + dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV", > > + __builtin_return_address(0), &vaf); > > + else > > + printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > > + __builtin_return_address(0), &vaf); > > + va_end(args); > > + } > > + > > + if (!drm_trace_enabled(category)) > > + return; > > + > > + for_each_set_bit(bit, (unsigned long*)&category, sizeof(category) * 8) { > > + va_start(args, format); > > + drm_do_trace(dev, BIT(bit), &vaf); > > + va_end(args); > > I'm thinking we could find a way to move the logic here to have a > single loop. Should be done with the enum conversion mentioned above. > > Note, the current approach is racy. The state can change between the > "drm_trace_enabled()" and this for loop. Yep, good catch. I think the race is ok since in that case the message will get dropped when we call drm_do_trace. The trace_enabled() call is just a fastpath for the majority case. Sean > > -- Steve > > > > + } > > > > - va_end(args); > > } > > EXPORT_SYMBOL(drm_dev_dbg); > > > > void drm_dbg(unsigned int category, const char *format, ...) > > { > > struct va_format vaf; > > + unsigned int bit; > > va_list args; > > > > - if (!drm_debug_enabled(category)) > > - return; > > - > > - va_start(args, format); > > vaf.fmt = format; > > vaf.va = &args; > > > > - printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > > - __builtin_return_address(0), &vaf); > > + if (drm_debug_enabled(category)) { > > + va_start(args, format); > > + printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > > + __builtin_return_address(0), &vaf); > > + va_end(args); > > + } > > > > - va_end(args); > > + if (!drm_trace_enabled(category)) > > + return; > > + > > + for_each_set_bit(bit, (unsigned long*)&category, sizeof(category) * 8) { > > + va_start(args, format); > > + drm_do_trace(NULL, BIT(bit), &vaf); > > + va_end(args); > > + } > > } > > EXPORT_SYMBOL(drm_dbg); > > > > @@ -304,13 +404,16 @@ void drm_err(const char *format, ...) > > struct va_format vaf; > > va_list args; > > > > - va_start(args, format); > > vaf.fmt = format; > > vaf.va = &args; > > > > + va_start(args, format); > > printk(KERN_ERR "[" DRM_NAME ":%ps] *ERROR* %pV", > > __builtin_return_address(0), &vaf); > > + va_end(args); > > > > + va_start(args, format); > > + trace_drm_err(NULL, &vaf); > > va_end(args); > > } > > EXPORT_SYMBOL(drm_err); > > diff --git a/include/trace/events/drm_print.h b/include/trace/events/drm_print.h > > new file mode 100644 > > index 000000000000..862728fe0f89 > > --- /dev/null > > +++ b/include/trace/events/drm_print.h > > @@ -0,0 +1,116 @@ > > +// SPDX-License-Identifier: MIT > > +/* > > + * Copyright (C) 2019 Google, Inc. > > + * > > + * Authors: > > + * Sean Paul <seanpaul@xxxxxxxxxxxx> > > + */ > > +#undef TRACE_SYSTEM > > +#define TRACE_SYSTEM drm_print > > + > > +#if !defined(_TRACE_DRM_PRINT_H) || defined(TRACE_HEADER_MULTI_READ) > > + > > +#include <linux/device.h> > > +#include <linux/tracepoint.h> > > + > > +#define DRM_PRINT_MAX 256 > > + > > +#define _TRACE_DRM_PRINT_H > > + > > +TRACE_EVENT(drm_log, > > + TP_PROTO(const char * level, const struct device *dev, > > + struct va_format *vaf), > > + TP_ARGS(level, dev, vaf), > > + TP_STRUCT__entry( > > + __field(const char *, level ) > > + __field(const struct device *, dev ) > > + __dynamic_array(char, msg, DRM_PRINT_MAX ) > > + __field(int, len ) > > + ), > > + TP_fast_assign( > > + __entry->level = level; > > + __entry->dev = dev; > > + __entry->len = vsnprintf(__get_str(msg), DRM_PRINT_MAX, > > + vaf->fmt, *vaf->va); > > + if (__entry->len > 0 && > > + __get_str(msg)[__entry->len - 1] == '\n') > > + __get_str(msg)[--__entry->len] = '\0'; > > + ), > > + TP_printk("%s %s %s: %s", __entry->level, > > + __entry->dev ? dev_driver_string(__entry->dev) : "(NULL):", > > + __entry->dev ? dev_name(__entry->dev) : "", __get_str(msg)) > > +); > > + > > +DECLARE_EVENT_CLASS(class_drm_category_log, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf), > > + TP_STRUCT__entry( > > + __field(const struct device *, dev ) > > + __dynamic_array(char, msg, DRM_PRINT_MAX ) > > + __field(int, len ) > > + ), > > + TP_fast_assign( > > + __entry->dev = dev; > > + __entry->len = vsnprintf(__get_str(msg), DRM_PRINT_MAX, > > + vaf->fmt, *vaf->va); > > + if (__entry->len > 0 && > > + __get_str(msg)[__entry->len - 1] == '\n') > > + __get_str(msg)[--__entry->len] = '\0'; > > + ), > > + TP_printk("%s %s%s%s", > > + __entry->dev ? dev_driver_string(__entry->dev) : "", > > + __entry->dev ? dev_name(__entry->dev) : "", > > + __entry->dev ? ": " : "", __get_str(msg)) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_err, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_none, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_core, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_driver, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_kms, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_prime, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_atomic, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_vbl, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_state, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_lease, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_dp, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +DEFINE_EVENT(class_drm_category_log, drm_dbg_unknown, > > + TP_PROTO(const struct device *dev, struct va_format *vaf), > > + TP_ARGS(dev, vaf) > > +); > > +#endif > > + > > +/* This part must be outside protection */ > > +#include <trace/define_trace.h> > -- Sean Paul, Software Engineer, Google / Chromium OS _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
