From: Jim Cromie <jim.cromie@gmail.com>
To: linux-kernel@vger.kernel.org, jbaron@akamai.com,
gregkh@linuxfoundation.org, dri-devel@lists.freedesktop.org,
amd-gfx@lists.freedesktop.org,
intel-gvt-dev@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org
Cc: daniel.vetter@ffwll.ch, jani.nikula@intel.com,
ville.syrjala@linux.intel.com, seanpaul@chromium.org,
robdclark@gmail.com, groeck@google.com, yanivt@google.com,
bleung@google.com, linux-doc@vger.kernel.org,
Jim Cromie <jim.cromie@gmail.com>
Subject: [PATCH v7 21/25] dyndbg: refactor *dynamic_emit_prefix
Date: Thu, 12 Oct 2023 11:21:32 -0600 [thread overview]
Message-ID: <20231012172137.3286566-22-jim.cromie@gmail.com> (raw)
In-Reply-To: <20231012172137.3286566-1-jim.cromie@gmail.com>
Refactor the split of duties between outer & inner fns.
The outer fn was previously just an inline unlikely forward to inner,
which did all the work.
Now, outer handles +t and +l flags itself, and calls inner only when
_DPRINTK_FLAGS_INCL_LOOKUP is needed.
No functional change.
But it does make the results of the inner-fn more cache-friendly
(fewer entries, reused more often):
1- no spurious [TID] or <intr> noise
2- no LINE-number to bloat the cache (avg 9 pr_debugs/fn)
3- only LOOKUP stuff
Currently LOOKUPs are descriptor-field refs but could be replaced by
accessor functions. This would allow the __dyndbg_sites section to be
de-duplicated and reclaimed; currently module, filename fields are
~90% repeated. As the accessors get more expensive, the value of
caching part of the prefix goes up.
Also change inner-fn to return count of extra chars written to the
buffer, and drop "inline" from outer, let the compiler decide. Maybe
also change name accordingly.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
lib/dynamic_debug.c | 55 ++++++++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 25 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 17eefb35ac96..974395bf8a83 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -777,19 +777,8 @@ static int remaining(int wrote)
return 0;
}
-static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
+static int __dynamic_emit_prefix(const struct _ddebug *desc, char *buf, int pos)
{
- int pos_after_tid;
- int pos = 0;
-
- if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
- if (in_interrupt())
- pos += snprintf(buf + pos, remaining(pos), "<intr> ");
- else
- pos += snprintf(buf + pos, remaining(pos), "[%d] ",
- task_pid_vnr(current));
- }
- pos_after_tid = pos;
if (desc->flags & _DPRINTK_FLAGS_INCL_MODNAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
desc->modname);
@@ -799,22 +788,38 @@ static char *__dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
if (desc->flags & _DPRINTK_FLAGS_INCL_SOURCENAME)
pos += snprintf(buf + pos, remaining(pos), "%s:",
trim_prefix(desc->filename));
- if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
- pos += snprintf(buf + pos, remaining(pos), "%d:",
- desc->lineno);
- if (pos - pos_after_tid)
- pos += snprintf(buf + pos, remaining(pos), " ");
- if (pos >= PREFIX_SIZE)
- buf[PREFIX_SIZE - 1] = '\0';
-
- return buf;
+ return pos;
}
-static inline char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
+static char *dynamic_emit_prefix(struct _ddebug *desc, char *buf)
{
- if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_ANY))
- return __dynamic_emit_prefix(desc, buf);
- return buf;
+ int pos_after_tid;
+ int pos = 0;
+
+ if (likely(!(desc->flags & _DPRINTK_FLAGS_INCL_ANY)))
+ return buf;
+
+ if (desc->flags & _DPRINTK_FLAGS_INCL_TID) {
+ if (in_interrupt())
+ pos += snprintf(buf + pos, remaining(pos), "<intr> ");
+ else
+ pos += snprintf(buf + pos, remaining(pos), "[%d] ",
+ task_pid_vnr(current));
+ }
+ pos_after_tid = pos;
+
+ if (unlikely(desc->flags & _DPRINTK_FLAGS_INCL_LOOKUP))
+ pos += __dynamic_emit_prefix(desc, buf, pos);
+
+ if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
+ pos += snprintf(buf + pos, remaining(pos), "%d:",
+ desc->lineno);
+ if (pos - pos_after_tid)
+ pos += snprintf(buf + pos, remaining(pos), " ");
+ if (pos >= PREFIX_SIZE)
+ buf[PREFIX_SIZE - 1] = '\0';
+
+ return buf;
}
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
--
2.41.0
next prev parent reply other threads:[~2023-10-12 17:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-12 17:21 [PATCH v7 00/25] fix DRM_USE_DYNAMIC_DEBUG=y regression Jim Cromie
2023-10-12 17:21 ` [PATCH v7 01/25] test-dyndbg: fixup CLASSMAP usage error Jim Cromie
2023-10-12 17:21 ` [PATCH v7 02/25] dyndbg: reword "class unknown," to "class:_UNKNOWN_" Jim Cromie
2023-10-12 17:21 ` [PATCH v7 03/25] dyndbg: make ddebug_class_param union members same size Jim Cromie
2023-10-12 17:21 ` [PATCH v7 04/25] dyndbg: replace classmap list with a vector Jim Cromie
2023-10-12 17:21 ` [PATCH v7 05/25] dyndbg: ddebug_apply_class_bitmap - add module arg, select on it Jim Cromie
2023-10-12 17:21 ` [PATCH v7 06/25] dyndbg: split param_set_dyndbg_classes to module/wrapper fns Jim Cromie
2023-10-12 17:21 ` [PATCH v7 07/25] dyndbg: drop NUM_TYPE_ARRAY Jim Cromie
2023-10-12 17:21 ` [PATCH v7 08/25] dyndbg: reduce verbose/debug clutter Jim Cromie
2023-10-12 17:21 ` [PATCH v7 09/25] dyndbg: silence debugs with no-change updates Jim Cromie
2023-10-12 17:21 ` [PATCH v7 10/25] dyndbg: tighten ddebug_class_name() 1st arg type Jim Cromie
2023-10-12 17:21 ` [PATCH v7 11/25] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap Jim Cromie
2023-10-12 17:21 ` [PATCH v7 12/25] dyndbg: reduce verbose=3 messages in ddebug_add_module Jim Cromie
2023-10-12 17:21 ` [PATCH v7 13/25] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code Jim Cromie
2023-10-12 17:21 ` [PATCH v7 14/25] dyndbg-API: fix CONFIG_DRM_USE_DYNAMIC_DEBUG regression Jim Cromie
2023-10-12 17:21 ` [PATCH v7 15/25] dyndbg: add for_each_boxed_vector Jim Cromie
2023-10-12 17:21 ` [PATCH v7 16/25] dyndbg: refactor ddebug_classparam_clamp_input Jim Cromie
2023-10-12 17:21 ` [PATCH v7 17/25] dyndbg-API: promote DYNDBG_CLASSMAP_PARAM to API Jim Cromie
2023-10-12 17:21 ` [PATCH v7 18/25] dyndbg-doc: add classmap info to howto Jim Cromie
2023-10-12 17:21 ` [PATCH v7 19/25] dyndbg: reserve flag bit _DPRINTK_FLAGS_PREFIX_CACHED Jim Cromie
2023-10-12 17:21 ` [PATCH v7 20/25] dyndbg: add _DPRINTK_FLAGS_INCL_LOOKUP Jim Cromie
2023-10-12 17:21 ` Jim Cromie [this message]
2023-10-12 17:21 ` [PATCH v7 22/25] dyndbg: improve err report in attach_user_module_classes Jim Cromie
2023-10-12 17:21 ` [PATCH v7 23/25] drm: use correct ccflags-y spelling Jim Cromie
2023-10-12 17:21 ` [PATCH v7 24/25] drm-drivers: DRM_CLASSMAP_USE in 2nd batch of drivers, helpers Jim Cromie
2023-10-12 17:21 ` [PATCH v7 25/25] drm: restore CONFIG_DRM_USE_DYNAMIC_DEBUG un-BROKEN Jim Cromie
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