Re: [Intel-gfx] [PATCH v7 3/8] i915/gvt: use DEFINE_DYNAMIC_DEBUG_CATEGORIES to create "gvt:core:" etc categories
From: Tvrtko Ursulin
Date: Mon Sep 06 2021 - 08:26:42 EST
On 03/09/2021 20:22, jim.cromie@xxxxxxxxx wrote:
On Fri, Sep 3, 2021 at 5:07 AM Tvrtko Ursulin
<tvrtko.ursulin@xxxxxxxxxxxxxxx> wrote:
On 31/08/2021 21:21, Jim Cromie wrote:
The gvt component of this driver has ~120 pr_debugs, in 9 categories
quite similar to those in DRM. Following the interface model of
drm.debug, add a parameter to map bits to these categorizations.
DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
"dyndbg bitmap desc",
{ "gvt:cmd: ", "command processing" },
{ "gvt:core: ", "core help" },
{ "gvt:dpy: ", "display help" },
{ "gvt:el: ", "help" },
{ "gvt:irq: ", "help" },
{ "gvt:mm: ", "help" },
{ "gvt:mmio: ", "help" },
{ "gvt:render: ", "help" },
{ "gvt:sched: " "help" });
BTW, Ive dropped the help field, its already handled, dont need to clutter.
The actual patch has a few details different, cmd_help() macro emits
the initialization construct.
if CONFIG_DRM_USE_DYNAMIC_DEBUG, then -DDYNAMIC_DEBUG_MODULE is added
cflags, by gvt/Makefile.
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
v5:
. static decl of vector of bit->class descriptors - Emil.V
. relocate gvt-makefile chunk from elsewhere
v7:
. move ccflags addition up to i915/Makefile from i915/gvt
---
drivers/gpu/drm/i915/Makefile | 4 ++++
drivers/gpu/drm/i915/i915_params.c | 35 ++++++++++++++++++++++++++++++
Can this work if put under gvt/ or at least intel_gvt.h|c?
I thought it belonged here more, at least according to the name of the
config.var
Hmm bear with me please - the categories this patch creates are intended
to be used explicitly from the GVT "sub-module", or they somehow even
get automatically used with no further intervention to callers required?
CONFIG_DRM_USE_DYNAMIC_DEBUG.
I suppose its not a great name, its narrow purpose is to swap
drm-debug api to use dyndbg. drm-evrything already "uses"
dyndbg if CONFIG_DYNAMIC_DEBUG=y, those gvt/pr_debugs in particular.
Theres also CONFIG_DYNAMIC_DEBUG_CORE=y,
which drm basically ignores currently.
So with the name CONFIG_DRM_USE_DYNAMIC_DEBUG
it seemed proper to arrange for that to be true on DD-CORE=y builds,
by adding -DDYNAMIC_DEBUG_MODULE
Does that make some sense ?
How to best resolve the frictions ?
new CONFIG names ?
2 files changed, 39 insertions(+)
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 4f22cac1c49b..5a4e371a3ec2 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -30,6 +30,10 @@ CFLAGS_display/intel_fbdev.o = $(call cc-disable-warning, override-init)
subdir-ccflags-y += -I$(srctree)/$(src)
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+ccflags-y += -DDYNAMIC_DEBUG_MODULE
+#endif
Ignores whether CONFIG_DRM_I915_GVT is enabled or not?
not intentionally.
I think theres 2 things youre noting:
1 - make frag into gvt/Makefile
I had it there earlier, not sure why I moved it up.
maybe some confusion on proper scope of the flag.
2 - move new declaration code in i915-param.c inside the gvt ifdef
Im good with that.
I'll probably copy the ifdef wrapper down rather than move the decl up.
ie:
#if __and(IS_ENABLED(CONFIG_DRM_I915_GVT),
IS_ENABLED(CONFIG_DRM_USE_DYNAMIC_DEBUG))
unsigned long __gvt_debug;
EXPORT_SYMBOL(__gvt_debug);
+
# Please keep these build lists sorted!
# core driver code
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index e07f4cfea63a..e645e149485e 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -265,3 +265,38 @@ void i915_params_free(struct i915_params *params)
I915_PARAMS_FOR_EACH(FREE);
#undef FREE
}
+
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+/* todo: needs DYNAMIC_DEBUG_MODULE in some cases */
+
+unsigned long __gvt_debug;
+EXPORT_SYMBOL(__gvt_debug);
+
+#define _help(key) "\t \"" key "\"\t: help for " key "\n"
+
+#define I915_GVT_CATEGORIES(name) \
+ " Enable debug output via /sys/module/i915/parameters/" #name \
+ ", where each bit enables a debug category.\n" \
+ _help("gvt:cmd:") \
+ _help("gvt:core:") \
+ _help("gvt:dpy:") \
+ _help("gvt:el:") \
+ _help("gvt:irq:") \
+ _help("gvt:mm:") \
+ _help("gvt:mmio:") \
+ _help("gvt:render:") \
+ _help("gvt:sched:")
+
+DEFINE_DYNAMIC_DEBUG_CATEGORIES(debug_gvt, __gvt_debug,
+ I915_GVT_CATEGORIES(debug_gvt),
+ _DD_cat_("gvt:cmd:"),
+ _DD_cat_("gvt:core:"),
+ _DD_cat_("gvt:dpy:"),
+ _DD_cat_("gvt:el:"),
+ _DD_cat_("gvt:irq:"),
+ _DD_cat_("gvt:mm:"),
+ _DD_cat_("gvt:mmio:"),
+ _DD_cat_("gvt:render:"),
+ _DD_cat_("gvt:sched:"));
+
+#endif
So just the foundation - no actual use sites I mean? How would these be
used from the code?
there are 120 pr_debug "users" :-)
no users per se, but anyone using drm.debug
/sys/module/drm/parameters/debug
might use this too.
its a bit easier than composing queries for >/proc/dyamic_debug/control
Same as my previous question, perhaps I am not up to speed with this
yet.. Even if pr_debug is used inside GVT - are the categories and
debug_gvt global as of this patch (or series)?
Regards,
Tvrtko