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Message-ID: <74f6ee77-523c-4943-9b3f-a9bcab78faa7@bootlin.com>
Date: Tue, 25 Feb 2025 15:19:41 +0100
From: Louis Chauvet <louis.chauvet@...tlin.com>
To: Jim Cromie <jim.cromie@...il.com>, linux-kernel@...r.kernel.org,
jbaron@...mai.com, gregkh@...uxfoundation.org, ukaszb@...omium.org
Cc: intel-gfx-trybot@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
amd-gfx@...ts.freedesktop.org, intel-gvt-dev@...ts.freedesktop.org,
intel-gfx@...ts.freedesktop.org, daniel.vetter@...ll.ch,
tvrtko.ursulin@...ux.intel.com, jani.nikula@...el.com,
ville.syrjala@...ux.intel.com
Subject: Re: [PATCH 19/63] dyndbg: make proper substructs in _ddebug_info
Le 25/01/2025 à 07:45, Jim Cromie a écrit :
> struct _ddebug_info's jobs is to enapsulate the __sections of dyndbg
> data from the linker. The data started as a single pair of fields:
> descs - ref'g an array of descriptors & num_descs - counting the
> "pertinent" descriptors. Then classes & num_classes were added, and
> _ddebug_info was invented to contain the 4 fields.
>
> When class_users & num_class_users were added (earlier in this
> series), the easy path was to replicate functions and adapt them to
> work on ddebug_class_users, instead of class_maps. This worked, but
> made repetitive boilerplate code, leading to (other commits with)
> macros walking num_##{classes,class_users} to capture the repetition.
>
> To fix it better, create structs to contain start,len for vectors of
> all 3 objects: classmaps, class_users, and pr_debug descriptors, and
> adjust field-refs accordingly.
>
> Also recompose struct ddebug_table to contain a _ddebug_info (rather
> than repeat the contents, as before), and adjust all array-walks to
> use the newly contained info.
>
> This allows ridding the class* macros of the num##<T> paste-up, and
> should enable further cleanups.
>
> NB: The __packed attribute on _ddebug_info and the 3 contained structs
> closes the holes otherwise created by the structification (which was
> the excuse for not doing it originally).
>
> TBD: see if this can precede other patches, to reduce churn
Hi Jim,
This could be amazing if possible!
> Signed-off-by: Jim Cromie <jim.cromie@...il.com>
Reviewed-by: Louis Chauvet <louis.chauvet@...tlin.com>
> ---
> include/linux/dynamic_debug.h | 29 ++++++++---
> kernel/module/main.c | 18 +++----
> lib/dynamic_debug.c | 93 +++++++++++++++++------------------
> 3 files changed, 74 insertions(+), 66 deletions(-)
>
> diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
> index 2b0c943af330..48d76a273f68 100644
> --- a/include/linux/dynamic_debug.h
> +++ b/include/linux/dynamic_debug.h
> @@ -173,15 +173,28 @@ struct ddebug_class_user {
> .map = &(_var), \
> }
>
> -/* encapsulate linker provided built-in (or module) dyndbg data */
> +/*
> + * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
> + * For builtins, it is used as a cursor, with the inner structs
> + * marking sub-vectors of the builtin __sections in DATA.
> + */
> +struct _ddebug_descs {
> + struct _ddebug *start;
> + int len;
> +} __packed;
> +struct dd_class_maps {
> + struct ddebug_class_map *start;
> + int len;
> +} __packed;
> +struct dd_class_users {
> + struct ddebug_class_user *start;
> + int len;
> +} __packed;
> struct _ddebug_info {
> - struct _ddebug *descs;
> - struct ddebug_class_map *classes;
> - struct ddebug_class_user *class_users;
> - unsigned int num_descs;
> - unsigned int num_classes;
> - unsigned int num_class_users;
> -};
> + struct _ddebug_descs descs;
> + struct dd_class_maps maps;
> + struct dd_class_users users;
> +} __packed;
>
> struct ddebug_class_param {
> union {
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index c394a0c6e8c6..858882a1eacd 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -2540,15 +2540,15 @@ static int find_module_sections(struct module *mod, struct load_info *info)
> pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
>
> #ifdef CONFIG_DYNAMIC_DEBUG_CORE
> - mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
> - sizeof(*mod->dyndbg_info.descs),
> - &mod->dyndbg_info.num_descs);
> - mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
> - sizeof(*mod->dyndbg_info.classes),
> - &mod->dyndbg_info.num_classes);
> - mod->dyndbg_info.class_users = section_objs(info, "__dyndbg_class_users",
> - sizeof(*mod->dyndbg_info.class_users),
> - &mod->dyndbg_info.num_class_users);
> + mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg",
> + sizeof(*mod->dyndbg_info.descs.start),
> + &mod->dyndbg_info.descs.len);
> + mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_classes",
> + sizeof(*mod->dyndbg_info.maps.start),
> + &mod->dyndbg_info.maps.len);
> + mod->dyndbg_info.users.start = section_objs(info, "__dyndbg_class_users",
> + sizeof(*mod->dyndbg_info.users.start),
> + &mod->dyndbg_info.users.len);
> #endif
>
> return 0;
> diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
> index 08b6e4e7489f..067db504dd1d 100644
> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -49,10 +49,7 @@ extern struct ddebug_class_user __stop___dyndbg_class_users[];
> struct ddebug_table {
> struct list_head link;
> const char *mod_name;
> - struct _ddebug *ddebugs;
> - struct ddebug_class_map *classes;
> - struct ddebug_class_user *class_users;
> - unsigned int num_ddebugs, num_classes, num_class_users;
> + struct _ddebug_info info;
> };
>
> struct ddebug_query {
> @@ -154,8 +151,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
> #define vpr_dt_info(dt_p, msg_p, ...) ({ \
> struct ddebug_table const *_dt = dt_p; \
> v2pr_info(msg_p " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
> - _dt->mod_name, _dt->num_ddebugs, _dt->num_classes, \
> - _dt->num_class_users); \
> + _dt->mod_name, _dt->info.descs.len, _dt->info.maps.len, \
> + _dt->info.users.len); \
> })
>
> /*
> @@ -168,8 +165,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
> * @_vec: name of a sub-struct member in _box, with array-ref and length
> */
> #define for_subvec(_i, _sp, _box, _vec) \
> - for ((_i) = 0, (_sp) = (_box)->_vec; \
> - (_i) < (_box)->num_##_vec; \
> + for ((_i) = 0, (_sp) = (_box)->_vec.start; \
> + (_i) < (_box)->_vec.len; \
> (_i)++, (_sp)++)
>
> static int ddebug_find_valid_class(struct ddebug_table const *dt, const char *class_string)
> @@ -178,14 +175,14 @@ static int ddebug_find_valid_class(struct ddebug_table const *dt, const char *cl
> struct ddebug_class_user *cli;
> int i, idx;
>
> - for_subvec(i, map, dt, classes) {
> + for_subvec(i, map, &dt->info, maps) {
> idx = match_string(map->class_names, map->length, class_string);
> if (idx >= 0) {
> vpr_dt_info(dt, "good-class: %s.%s ", map->mod_name, class_string);
> return idx + map->base;
> }
> }
> - for_subvec(i, cli, dt, class_users) {
> + for_subvec(i, cli, &dt->info, users) {
> idx = match_string(cli->map->class_names, cli->map->length, class_string);
> if (idx >= 0) {
> vpr_dt_info(dt, "class-ref: %s -> %s.%s ",
> @@ -229,8 +226,8 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
> valid_class = _DPRINTK_CLASS_DFLT;
> }
>
> - for (i = 0; i < dt->num_ddebugs; i++) {
> - struct _ddebug *dp = &dt->ddebugs[i];
> + for (i = 0; i < dt->info.descs.len; i++) {
> + struct _ddebug *dp = &dt->info.descs.start[i];
>
> /* match site against query-class */
> if (dp->class_id != valid_class)
> @@ -990,8 +987,8 @@ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
> }
> iter->table = list_entry(ddebug_tables.next,
> struct ddebug_table, link);
> - iter->idx = iter->table->num_ddebugs;
> - return &iter->table->ddebugs[--iter->idx];
> + iter->idx = iter->table->info.descs.len;
> + return &iter->table->info.descs.start[--iter->idx];
> }
>
> /*
> @@ -1012,10 +1009,10 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
> }
> iter->table = list_entry(iter->table->link.next,
> struct ddebug_table, link);
> - iter->idx = iter->table->num_ddebugs;
> + iter->idx = iter->table->info.descs.len;
> --iter->idx;
> }
> - return &iter->table->ddebugs[iter->idx];
> + return &iter->table->info.descs.start[iter->idx];
> }
>
> /*
> @@ -1064,15 +1061,15 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
>
> static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
> {
> - struct ddebug_class_map *map = dt->classes;
> - struct ddebug_class_user *cli = dt->class_users;
> + struct ddebug_class_map *map;
> + struct ddebug_class_user *cli;
> int i;
>
> - for (i = 0; i < dt->num_classes; i++, map++)
> + for_subvec(i, map, &dt->info, maps)
> if (class_in_range(dp->class_id, map))
> return map->class_names[dp->class_id - map->base];
>
> - for (i = 0; i < dt->num_class_users; i++, cli++)
> + for_subvec(i, cli, &dt->info, users)
> if (class_in_range(dp->class_id, cli->map))
> return cli->map->class_names[dp->class_id - cli->map->base];
>
> @@ -1203,8 +1200,7 @@ static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *m
>
> if (cm->mod) {
> vpr_cm_info(cm, "loaded classmap: %s", modnm);
> - /* ifdef protects the cm->mod->kp deref */
> - for_subvec(i, kp, cm->mod, kp)
> + for (i = 0, kp = cm->mod->kp; i < cm->mod->num_kp; i++, kp++)
> ddebug_match_apply_kparam(kp, cm, modnm);
> }
> #endif
> @@ -1226,20 +1222,20 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt,
> struct ddebug_class_map *cm;
> int i, nc = 0;
>
> - for_subvec(i, cm, di, classes) {
> + for_subvec(i, cm, di, maps) {
> if (!strcmp(cm->mod_name, dt->mod_name)) {
> vpr_cm_info(cm, "classes[%d]:", i);
> if (!nc++)
> - dt->classes = cm;
> + dt->info.maps.start = cm;
> }
> }
> if (!nc)
> return;
>
> vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
> - dt->num_classes = nc;
> + dt->info.maps.len = nc;
>
> - for_subvec(i, cm, dt, classes)
> + for_subvec(i, cm, &dt->info, maps)
> ddebug_apply_params(cm, cm->mod_name);
> }
>
> @@ -1259,23 +1255,23 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
> * module's refs, save to dt. For loadables, this is the
> * whole array.
> */
> - for_subvec(i, cli, di, class_users) {
> + for_subvec(i, cli, di, users) {
> if (WARN_ON_ONCE(!cli || !cli->map || !cli->mod_name))
> continue;
> if (!strcmp(cli->mod_name, dt->mod_name)) {
> vpr_cm_info(cli->map, "class_ref[%d] %s -> %s", i,
> cli->mod_name, cli->map->mod_name);
> if (!nc++)
> - dt->class_users = cli;
> + dt->info.users.start = cli;
> }
> }
> if (!nc)
> return;
>
> - dt->num_class_users = nc;
> + dt->info.users.len = nc;
>
> /* now iterate dt */
> - for_subvec(i, cli, di, class_users)
> + for_subvec(i, cli, di, users)
> ddebug_apply_params(cli->map, cli->mod_name);
>
> vpr_dt_info(dt, "attach-client-module: ");
> @@ -1291,10 +1287,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
> struct _ddebug *iter;
> int i, class_ct = 0;
>
> - if (!di->num_descs)
> + if (!di->descs.len)
> return 0;
>
> - v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
> + v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
>
> dt = kzalloc(sizeof(*dt), GFP_KERNEL);
> if (dt == NULL) {
> @@ -1308,8 +1304,7 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
> * this struct ddebug_table.
> */
> dt->mod_name = modname;
> - dt->ddebugs = di->descs;
> - dt->num_ddebugs = di->num_descs;
> + dt->info.descs = di->descs;
>
> INIT_LIST_HEAD(&dt->link);
>
> @@ -1317,17 +1312,17 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
> if (iter->class_id != _DPRINTK_CLASS_DFLT)
> class_ct++;
>
> - if (class_ct && di->num_classes)
> + if (class_ct && di->maps.len)
> ddebug_attach_module_classes(dt, di);
>
> mutex_lock(&ddebug_lock);
> list_add_tail(&dt->link, &ddebug_tables);
> mutex_unlock(&ddebug_lock);
>
> - if (class_ct && di->num_class_users)
> + if (class_ct && di->users.len)
> ddebug_attach_user_module_classes(dt, di);
>
> - vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
> + vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
> return 0;
> }
>
> @@ -1474,12 +1469,12 @@ static int __init dynamic_debug_init(void)
> char *cmdline;
>
> struct _ddebug_info di = {
> - .descs = __start___dyndbg,
> - .classes = __start___dyndbg_classes,
> - .class_users = __start___dyndbg_class_users,
> - .num_descs = __stop___dyndbg - __start___dyndbg,
> - .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
> - .num_class_users = __stop___dyndbg_class_users - __start___dyndbg_class_users,
> + .descs.start = __start___dyndbg,
> + .maps.start = __start___dyndbg_classes,
> + .users.start = __start___dyndbg_class_users,
> + .descs.len = __stop___dyndbg - __start___dyndbg,
> + .maps.len = __stop___dyndbg_classes - __start___dyndbg_classes,
> + .users.len = __stop___dyndbg_class_users - __start___dyndbg_class_users,
> };
>
> #ifdef CONFIG_MODULES
> @@ -1508,8 +1503,8 @@ static int __init dynamic_debug_init(void)
>
> if (strcmp(modname, iter->modname)) {
> mod_ct++;
> - di.num_descs = mod_sites;
> - di.descs = iter_mod_start;
> + di.descs.len = mod_sites;
> + di.descs.start = iter_mod_start;
> ret = ddebug_add_module(&di, modname);
> if (ret)
> goto out_err;
> @@ -1519,8 +1514,8 @@ static int __init dynamic_debug_init(void)
> iter_mod_start = iter;
> }
> }
> - di.num_descs = mod_sites;
> - di.descs = iter_mod_start;
> + di.descs.len = mod_sites;
> + di.descs.start = iter_mod_start;
> ret = ddebug_add_module(&di, modname);
> if (ret)
> goto out_err;
> @@ -1530,8 +1525,8 @@ static int __init dynamic_debug_init(void)
> i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
> (int)((i * sizeof(struct _ddebug)) >> 10));
>
> - if (di.num_classes)
> - v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
> + if (di.maps.len)
> + v2pr_info(" %d builtin ddebug class-maps\n", di.maps.len);
>
> /* now that ddebug tables are loaded, process all boot args
> * again to find and activate queries given in dyndbg params.
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
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