On Wed, Dec 07, 2016 at 06:35:29PM +0000, Robert Bragg wrote:
> This is still missing corresponding documentation changes, and I haven't
> moved anything to drm_print.h yet, as suggested.
>
> Sending out with a few functional improvements first to get agreement
> before documenting anything (changes summarised in v2: section below)
>
> In particular, affecting the output format, I stole an idea from Tvrtko
> Ursulin to have the prefix for messages be based on the driver name,
> such as "[i915]" instead of always being "[drm]".
>
> Depending on peoples thoughts on compatibility, we could consider
> removing the prefix given that the dynamic debug control interface has a
> way of specifying that messages should include a module name, function
> or line info like:
>
> echo "module i915 +mfp" > dynamic_debug/control
>
> That would enable all i915 debug messages with a module and function
> prefix.
>
> A trade-off would be that anyone only using the drm.drm_debug interface
> to control messages would loose some information. If we really wanted we
> could have the best of both by adding a utility printing api that can
> recognise when printing due to a dynamic debug control query vs
> drm.drm_debug to conditionally add the prefix.
>
> --- >8 --- (git am --scissors)
>
> Dynamic debug messages (ref: Documentation/dynamic-debug-howto.txt)
> allow fine grained control over which debug messages are enabled with
> runtime control through /sysfs/kernel/debug/dynamic_debug/control
>
> This provides more control than the current drm.drm_debug parameter
> which for some use cases is impractical to use given how chatty
> some drm debug categories are.
>
> For example all debug messages in i915_drm.c can be enabled with:
> echo "file i915_perf.c +p" > dynamic_debug/control
>
> This doesn't strictly maintain format compatibility with the previous
> debug messages since the category is now added as part of the prefix
> like "[drm][kms] No FB found". Adding the categories with a consistent
> format makes it possible to enable categories with a dynamic debug
> query like: echo "format [kms] +p" > dynamic_debug/control
>
> This maintains support for enabling debug messages using the drm_debug
> parameter. If dynamic debug is not enabled via CONFIG_DYNAMIC_DEBUG the
> debug messages essentially work as before, except with the inclusion of
> categories in the format strings as described above.
>
> This removes the drm_[dev_]printk wrappers considering that the dynamic
> debug macros are only useful if they can track the __FILE__, __func__
> and __LINE__ where they are called. The wrapper didn't seem necessary in
> the DRM_UT_NONE case with no category flag.
>
> The non _DEV macros are no longer defined in terms of passing NULL to a
> _DEV variant to avoid have the core.c dev_printk implementation adding
> "(NULL device *)". The previous drm_[dev_]prink function used to handle
> this as a special case.
>
> Instead of using DRM_NAME to add [drm] to the start of every message,
> the prefix is now based on module_name(THIS_MODULE) so it will be [drm]
> or e.g. [i915] for the Intel driver. Later we might consider removing
> the prefix altogether considering that the dynamic debug control
> interface has a way of optionally adding the module, function or line to
> the formatting of messages.
>
> v2:
> Add categories to format like "[drm][kms] No FB found"
> Only single conditional call per message (macros expand to less code)
> Uses __dynamic_pr_debug/dev_dbg for dynamic formatting features
> Use module name for msg prefix like [drm] or [i915]
>
> Signed-off-by: Robert Bragg <rob...@sixbynine.org>
> Cc: dri-de...@lists.freedesktop.org
> Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
> Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
So assuming I understand it correctly - I like this 3way cascade of
dynamic debug, then printk and no_printk fallback if CONFIG_DEBUG=n for
the space concious. But I guess we do need to add a DRM Kconfig knob to
set DEBUG, at least I'm not entirely sure how that's supposed to work. Or
we might need to have our own #ifdef maze for this. Maybe we need to keep
the old drm*printk stuff for that?
Anyway, I still think this is pretty cool, if we can get some common
ground with Tvrtko's stuff and some acks and reviews then I can pull it
in.
-Daniel
> ---
> drivers/gpu/drm/drm_drv.c | 47 -----------
> include/drm/drmP.h | 202
> +++++++++++++++++++++++++++++-----------------
> 2 files changed, 127 insertions(+), 122 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index f74b7d0..25d00aa 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -65,53 +65,6 @@ static struct idr drm_minors_idr;
>
> static struct dentry *drm_debugfs_root;
>
> -#define DRM_PRINTK_FMT "[" DRM_NAME ":%s]%s %pV"
> -
> -void drm_dev_printk(const struct device *dev, const char *level,
> - unsigned int category, const char *function_name,
> - const char *prefix, const char *format, ...)
> -{
> - struct va_format vaf;
> - va_list args;
> -
> - if (category != DRM_UT_NONE && !(drm_debug & category))
> - return;
> -
> - va_start(args, format);
> - vaf.fmt = format;
> - vaf.va = &args;
> -
> - if (dev)
> - dev_printk(level, dev, DRM_PRINTK_FMT, function_name, prefix,
> - &vaf);
> - else
> - printk("%s" DRM_PRINTK_FMT, level, function_name, prefix, &vaf);
> -
> - va_end(args);
> -}
> -EXPORT_SYMBOL(drm_dev_printk);
> -
> -void drm_printk(const char *level, unsigned int category,
> - const char *format, ...)
> -{
> - struct va_format vaf;
> - va_list args;
> -
> - if (category != DRM_UT_NONE && !(drm_debug & category))
> - return;
> -
> - va_start(args, format);
> - vaf.fmt = format;
> - vaf.va = &args;
> -
> - printk("%s" "[" DRM_NAME ":%ps]%s %pV",
> - level, __builtin_return_address(0),
> - strcmp(level, KERN_ERR) == 0 ? " *ERROR*" : "", &vaf);
> -
> - va_end(args);
> -}
> -EXPORT_SYMBOL(drm_printk);
> -
> /*
> * DRM Minors
> * A DRM device can provide several char-dev interfaces on the DRM-Major.
> Each
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index a9cfd33..0416114 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -58,6 +58,7 @@
> #include <linux/vmalloc.h>
> #include <linux/workqueue.h>
> #include <linux/dma-fence.h>
> +#include <linux/dynamic_debug.h>
>
> #include <asm/mman.h>
> #include <asm/pgalloc.h>
> @@ -129,15 +130,22 @@ struct dma_buf_attachment;
> * run-time by echoing the debug value in its sysfs node:
> * # echo 0xf > /sys/module/drm/parameters/debug
> */
> -#define DRM_UT_NONE 0x00
> #define DRM_UT_CORE 0x01
> +#define _DRM_UT_core 0x01
> #define DRM_UT_DRIVER 0x02
> +#define _DRM_UT_drv 0x02
> #define DRM_UT_KMS 0x04
> +#define _DRM_UT_kms 0x04
> #define DRM_UT_PRIME 0x08
> +#define _DRM_UT_prime 0x08
> #define DRM_UT_ATOMIC 0x10
> +#define _DRM_UT_atomic 0x10
> #define DRM_UT_VBL 0x20
> +#define _DRM_UT_vbl 0x20
> #define DRM_UT_STATE 0x40
>
> +#define _DRM_PREFIX module_name(THIS_MODULE)
> +
> /***********************************************************************/
> /** \name DRM template customization defaults */
> /*@{*/
> @@ -146,25 +154,19 @@ struct dma_buf_attachment;
> /** \name Macros to make printk easier */
> /*@{*/
>
> -#define _DRM_PRINTK(once, level, fmt, ...) \
> - do { \
> - printk##once(KERN_##level "[" DRM_NAME "] " fmt, \
> - ##__VA_ARGS__); \
> - } while (0)
> -
> -#define DRM_INFO(fmt, ...) \
> - _DRM_PRINTK(, INFO, fmt, ##__VA_ARGS__)
> -#define DRM_NOTE(fmt, ...) \
> - _DRM_PRINTK(, NOTICE, fmt, ##__VA_ARGS__)
> -#define DRM_WARN(fmt, ...) \
> - _DRM_PRINTK(, WARNING, fmt, ##__VA_ARGS__)
> -
> -#define DRM_INFO_ONCE(fmt, ...)
> \
> - _DRM_PRINTK(_once, INFO, fmt, ##__VA_ARGS__)
> -#define DRM_NOTE_ONCE(fmt, ...)
> \
> - _DRM_PRINTK(_once, NOTICE, fmt, ##__VA_ARGS__)
> -#define DRM_WARN_ONCE(fmt, ...)
> \
> - _DRM_PRINTK(_once, WARNING, fmt, ##__VA_ARGS__)
> +#define DRM_INFO(fmt, args...)
> \
> + pr_info("[%s] " fmt, _DRM_PREFIX, ##args)
> +#define DRM_NOTE(fmt, args...)
> \
> + pr_notice("[%s] " fmt, _DRM_PREFIX, ##args)
> +#define DRM_WARN(fmt, args...)
> \
> + pr_warn("[%s] " fmt, _DRM_PREFIX, ##args)
> +
> +#define DRM_INFO_ONCE(fmt, args...) \
> + pr_info_once("[%s] " fmt, _DRM_PREFIX, ##args)
> +#define DRM_NOTE_ONCE(fmt, args...) \
> + pr_notice_once("[%s] " fmt, _DRM_PREFIX, ##args)
> +#define DRM_WARN_ONCE(fmt, args...) \
> + pr_warn_once("[%s] " fmt, _DRM_PREFIX, ##args)
>
> /**
> * Error output.
> @@ -172,11 +174,10 @@ struct dma_buf_attachment;
> * \param fmt printf() like format string.
> * \param arg arguments
> */
> -#define DRM_DEV_ERROR(dev, fmt, ...) \
> - drm_dev_printk(dev, KERN_ERR, DRM_UT_NONE, __func__, " *ERROR*",\
> - fmt, ##__VA_ARGS__)
> -#define DRM_ERROR(fmt, ...) \
> - drm_printk(KERN_ERR, DRM_UT_NONE, fmt, ##__VA_ARGS__)
> +#define DRM_DEV_ERROR(dev, fmt, args...) \
> + dev_err(dev, "[%s:%s]*ERROR*" fmt, _DRM_PREFIX, __func__, ##args)
> +#define DRM_ERROR(fmt, args...)
> \
> + pr_err("[%s:%s]*ERROR*" fmt, _DRM_PREFIX, __func__, ##args)
>
> /**
> * Rate limited error output. Like DRM_ERROR() but won't flood the log.
> @@ -184,81 +185,129 @@ struct dma_buf_attachment;
> * \param fmt printf() like format string.
> * \param arg arguments
> */
> -#define DRM_DEV_ERROR_RATELIMITED(dev, fmt, ...) \
> +#define DRM_DEV_ERROR_RATELIMITED(dev, fmt, args...) \
> ({ \
> static DEFINE_RATELIMIT_STATE(_rs, \
> DEFAULT_RATELIMIT_INTERVAL, \
> DEFAULT_RATELIMIT_BURST); \
> \
> if (__ratelimit(&_rs)) \
> - DRM_DEV_ERROR(dev, fmt, ##__VA_ARGS__); \
> + DRM_DEV_ERROR(dev, fmt, ##args); \
> })
> -#define DRM_ERROR_RATELIMITED(fmt, ...)
> \
> - DRM_DEV_ERROR_RATELIMITED(NULL, fmt, ##__VA_ARGS__)
> -
> -#define DRM_DEV_INFO(dev, fmt, ...) \
> - drm_dev_printk(dev, KERN_INFO, DRM_UT_NONE, __func__, "", fmt, \
> - ##__VA_ARGS__)
> -
> -#define DRM_DEV_INFO_ONCE(dev, fmt, ...) \
> +#define DRM_ERROR_RATELIMITED(fmt, args...) \
> ({ \
> - static bool __print_once __read_mostly; \
> - if (!__print_once) { \
> - __print_once = true; \
> - DRM_DEV_INFO(dev, fmt, ##__VA_ARGS__); \
> - } \
> + static DEFINE_RATELIMIT_STATE(_rs, \
> + DEFAULT_RATELIMIT_INTERVAL, \
> + DEFAULT_RATELIMIT_BURST); \
> + \
> + if (__ratelimit(&_rs)) \
> + DRM_ERROR(fmt, ##args); \
> })
>
> +#define DRM_DEV_INFO(dev, fmt, args...)
> \
> + dev_info(dev, "[%s:%s] " fmt, _DRM_PREFIX, __func__, ##args)
> +
> +#define DRM_DEV_INFO_ONCE(dev, fmt, args...) \
> + dev_info_once(dev, "[%s:%s] " fmt, _DRM_PREFIX, __func__, ##args)
> +
> /**
> * Debug output.
> *
> * \param fmt printf() like format string.
> * \param arg arguments
> */
> +
> +#if defined(CONFIG_DYNAMIC_DEBUG)
> +#define DRM_DEF_DYN_DEBUG_DATA(name, fmt) \
> + DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt);
> +#define DRM_DYN_DEBUG_BRANCH(descriptor) \
> + DYNAMIC_DEBUG_BRANCH(descriptor)
> +
> +#define __drm_dyn_dev_dbg(descriptor, dev, fmt, args...) \
> + __dynamic_dev_dbg(descriptor, dev, fmt, ##args)
> +#define __drm_dyn_pr_debug(descriptor, fmt, args...) \
> + __dynamic_pr_debug(descriptor, fmt, ##args)
> +#else
> +#define DRM_DEF_DYN_DEBUG_DATA(name, fmt) do {} while(0)
> +#define DRM_DYN_DEBUG_BRANCH(descriptor) 0
> +
> +#define __drm_dyn_dev_dbg(descriptor, dev, fmt, args...) \
> + dev_dbg(dev, fmt, ##args)
> +#define __drm_dyn_pr_debug(descriptor, fmt, args...) \
> + pr_debug(fmt, ##args)
> +#endif
> +
> +/* If modifying, note the duplication of the format strings for the
> + * dynamic debug meta data and for passing to printk. We don't
> + * deref descriptor->format to handle building without
> + * CONFIG_DYNAMIC_DEBUG
> + */
> +#define _DRM_DEV_DEBUG(dev, cat, fmt, args...)
> \
> +({ \
> + DRM_DEF_DYN_DEBUG_DATA(descriptor, "[%s:%s]["#cat"] " fmt); \
> + if (DRM_DYN_DEBUG_BRANCH(descriptor) || \
> + unlikely(drm_debug & _DRM_UT_##cat)) { \
> + __drm_dyn_dev_dbg(&descriptor, dev, \
> + "[%s:%s]["#cat"] " fmt, \
> + _DRM_PREFIX, __func__, ##args); \
> + } \
> +})
> +#define _DRM_DEBUG(cat, fmt, args...)
> \
> +({ \
> + DRM_DEF_DYN_DEBUG_DATA(descriptor, "[%s:%s]["#cat"] " fmt); \
> + if (DRM_DYN_DEBUG_BRANCH(descriptor) || \
> + unlikely(drm_debug & _DRM_UT_##cat)) { \
> + __drm_dyn_pr_debug(&descriptor, \
> + "[%s:%s]["#cat"] " fmt, \
> + _DRM_PREFIX, __func__, ##args); \
> + } \
> +})
> +
> #define DRM_DEV_DEBUG(dev, fmt, args...) \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_CORE, __func__, "", fmt, \
> - ##args)
> -#define DRM_DEBUG(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_CORE, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, core, fmt, ##args)
> +#define DRM_DEBUG(fmt, args...)
> \
> + _DRM_DEBUG(core, fmt, ##args)
>
> #define DRM_DEV_DEBUG_DRIVER(dev, fmt, args...)
> \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_DRIVER, __func__, "", \
> - fmt, ##args)
> -#define DRM_DEBUG_DRIVER(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, drv, fmt, ##args)
> +#define DRM_DEBUG_DRIVER(fmt, args...)
> \
> + _DRM_DEBUG(drv, fmt, ##args)
>
> #define DRM_DEV_DEBUG_KMS(dev, fmt, args...) \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_KMS, __func__, "", fmt, \
> - ##args)
> -#define DRM_DEBUG_KMS(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_KMS, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, kms, fmt, ##args)
> +#define DRM_DEBUG_KMS(fmt, args...) \
> + _DRM_DEBUG(kms, fmt, ##args)
>
> #define DRM_DEV_DEBUG_PRIME(dev, fmt, args...)
> \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_PRIME, __func__, "", \
> - fmt, ##args)
> -#define DRM_DEBUG_PRIME(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_PRIME, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, prime, fmt, ##args)
> +#define DRM_DEBUG_PRIME(fmt, args...)
> \
> + _DRM_DEBUG(prime, fmt, ##args)
>
> #define DRM_DEV_DEBUG_ATOMIC(dev, fmt, args...)
> \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_ATOMIC, __func__, "", \
> - fmt, ##args)
> -#define DRM_DEBUG_ATOMIC(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, atomic, fmt, ##args)
> +#define DRM_DEBUG_ATOMIC(fmt, args...)
> \
> + _DRM_DEBUG(atomic, fmt, ##args)
>
> #define DRM_DEV_DEBUG_VBL(dev, fmt, args...) \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_VBL, __func__, "", fmt, \
> - ##args)
> -#define DRM_DEBUG_VBL(fmt, ...) \
> - drm_printk(KERN_DEBUG, DRM_UT_VBL, fmt, ##__VA_ARGS__)
> + _DRM_DEV_DEBUG(dev, vbl, fmt, ##args)
> +#define DRM_DEBUG_VBL(fmt, args...) \
> + _DRM_DEBUG(vbl, fmt, ##args)
>
> -#define _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, level, fmt, args...) \
> +#define _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, category, fmt, args...)
> \
> ({ \
> static DEFINE_RATELIMIT_STATE(_rs, \
> DEFAULT_RATELIMIT_INTERVAL, \
> DEFAULT_RATELIMIT_BURST); \
> if (__ratelimit(&_rs)) \
> - drm_dev_printk(dev, KERN_DEBUG, DRM_UT_ ## level, \
> - __func__, "", fmt, ##args); \
> + _DRM_DEV_DEBUG(dev, category, fmt, ##args); \
> +})
> +#define _DRM_DEFINE_DEBUG_RATELIMITED(category, fmt, args...) \
> +({ \
> + static DEFINE_RATELIMIT_STATE(_rs, \
> + DEFAULT_RATELIMIT_INTERVAL, \
> + DEFAULT_RATELIMIT_BURST); \
> + if (__ratelimit(&_rs)) \
> + _DRM_DEBUG(category, fmt, ##args); \
> })
>
> /**
> @@ -268,21 +317,24 @@ struct dma_buf_attachment;
> * \param arg arguments
> */
> #define DRM_DEV_DEBUG_RATELIMITED(dev, fmt, args...) \
> - DEV__DRM_DEFINE_DEBUG_RATELIMITED(dev, CORE, fmt, ##args)
> + _DRM_DEFINE_DEBUG_RATELIMITED(dev, core, fmt, ##args)
> #define DRM_DEBUG_RATELIMITED(fmt, args...) \
> - DRM_DEV_DEBUG_RATELIMITED(NULL, fmt, ##args)
> + _DRM_DEFINE_DEBUG_RATELIMITED(core, fmt, ##args)
> +
> #define DRM_DEV_DEBUG_DRIVER_RATELIMITED(dev, fmt, args...) \
> - _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, DRIVER, fmt, ##args)
> + _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, drv, fmt, ##args)
> #define DRM_DEBUG_DRIVER_RATELIMITED(fmt, args...) \
> - DRM_DEV_DEBUG_DRIVER_RATELIMITED(NULL, fmt, ##args)
> + _DRM_DEV_DEFINE_DEBUG_RATELIMITED(drv, fmt, ##args)
> +
> #define DRM_DEV_DEBUG_KMS_RATELIMITED(dev, fmt, args...) \
> - _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, KMS, fmt, ##args)
> + _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, kms, fmt, ##args)
> #define DRM_DEBUG_KMS_RATELIMITED(fmt, args...)
> \
> - DRM_DEV_DEBUG_KMS_RATELIMITED(NULL, fmt, ##args)
> + _DRM_DEFINE_DEBUG_RATELIMITED(kms, fmt, ##args)
> +
> #define DRM_DEV_DEBUG_PRIME_RATELIMITED(dev, fmt, args...) \
> - _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, PRIME, fmt, ##args)
> + _DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, prime, fmt, ##args)
> #define DRM_DEBUG_PRIME_RATELIMITED(fmt, args...) \
> - DRM_DEV_DEBUG_PRIME_RATELIMITED(NULL, fmt, ##args)
> + _DRM_DEFINE_DEBUG_RATELIMITED(prime, fmt, ##args)
>
> /* Format strings and argument splitters to simplify printing
> * various "complex" objects
> --
> 2.10.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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