| Message ID | 20230224-track_gt-v7-2-11f08358c1ec@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: use ref_tracker library for tracking wakerefs | expand |
On Fri, Apr 21, 2023 at 1:35 PM Andrzej Hajda <andrzej.hajda@intel.com> wrote: > > In case the library is tracking busy subsystem, simply > printing stack for every active reference will spam log > with long, hard to read, redundant stack traces. To improve > readabilty following changes have been made: > - reports are printed per stack_handle - log is more compact, > - added display name for ref_tracker_dir - it will differentiate > multiple subsystems, > - stack trace is printed indented, in the same printk call, > - info about dropped references is printed as well. > > Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> > Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> > --- > include/linux/ref_tracker.h | 15 ++++++-- > lib/ref_tracker.c | 90 +++++++++++++++++++++++++++++++++++++++------ > 2 files changed, 91 insertions(+), 14 deletions(-) > > diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h > index 87a92f2bec1b88..fc9ef9952f01fd 100644 > --- a/include/linux/ref_tracker.h > +++ b/include/linux/ref_tracker.h > @@ -17,12 +17,19 @@ struct ref_tracker_dir { > bool dead; > struct list_head list; /* List of active trackers */ > struct list_head quarantine; /* List of dead trackers */ > + char name[32]; > #endif > }; > > #ifdef CONFIG_REF_TRACKER > -static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, > - unsigned int quarantine_count) > + > +/* Temporary allow two and three arguments, until consumers are converted */ > +#define ref_tracker_dir_init(_d, _q, args...) _ref_tracker_dir_init(_d, _q, ##args, #_d) > +#define _ref_tracker_dir_init(_d, _q, _n, ...) __ref_tracker_dir_init(_d, _q, _n) > + We only have four callers of ref_tracker_dir_init() . Why not simply add a name on them, and avoid this magic ?
On 21.04.2023 16:21, Eric Dumazet wrote: > On Fri, Apr 21, 2023 at 1:35 PM Andrzej Hajda <andrzej.hajda@intel.com> wrote: >> In case the library is tracking busy subsystem, simply >> printing stack for every active reference will spam log >> with long, hard to read, redundant stack traces. To improve >> readabilty following changes have been made: >> - reports are printed per stack_handle - log is more compact, >> - added display name for ref_tracker_dir - it will differentiate >> multiple subsystems, >> - stack trace is printed indented, in the same printk call, >> - info about dropped references is printed as well. >> >> Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> >> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> >> --- >> include/linux/ref_tracker.h | 15 ++++++-- >> lib/ref_tracker.c | 90 +++++++++++++++++++++++++++++++++++++++------ >> 2 files changed, 91 insertions(+), 14 deletions(-) >> >> diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h >> index 87a92f2bec1b88..fc9ef9952f01fd 100644 >> --- a/include/linux/ref_tracker.h >> +++ b/include/linux/ref_tracker.h >> @@ -17,12 +17,19 @@ struct ref_tracker_dir { >> bool dead; >> struct list_head list; /* List of active trackers */ >> struct list_head quarantine; /* List of dead trackers */ >> + char name[32]; >> #endif >> }; >> >> #ifdef CONFIG_REF_TRACKER >> -static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, >> - unsigned int quarantine_count) >> + >> +/* Temporary allow two and three arguments, until consumers are converted */ >> +#define ref_tracker_dir_init(_d, _q, args...) _ref_tracker_dir_init(_d, _q, ##args, #_d) >> +#define _ref_tracker_dir_init(_d, _q, _n, ...) __ref_tracker_dir_init(_d, _q, _n) >> + > We only have four callers of ref_tracker_dir_init() . > > Why not simply add a name on them, and avoid this magic ? If this can be done in one patch, that's great. Regards Andrzej
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h index 87a92f2bec1b88..fc9ef9952f01fd 100644 --- a/include/linux/ref_tracker.h +++ b/include/linux/ref_tracker.h @@ -17,12 +17,19 @@ struct ref_tracker_dir { bool dead; struct list_head list; /* List of active trackers */ struct list_head quarantine; /* List of dead trackers */ + char name[32]; #endif }; #ifdef CONFIG_REF_TRACKER -static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, - unsigned int quarantine_count) + +/* Temporary allow two and three arguments, until consumers are converted */ +#define ref_tracker_dir_init(_d, _q, args...) _ref_tracker_dir_init(_d, _q, ##args, #_d) +#define _ref_tracker_dir_init(_d, _q, _n, ...) __ref_tracker_dir_init(_d, _q, _n) + +static inline void __ref_tracker_dir_init(struct ref_tracker_dir *dir, + unsigned int quarantine_count, + const char *name) { INIT_LIST_HEAD(&dir->list); INIT_LIST_HEAD(&dir->quarantine); @@ -31,6 +38,7 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, dir->dead = false; refcount_set(&dir->untracked, 1); refcount_set(&dir->no_tracker, 1); + strlcpy(dir->name, name, sizeof(dir->name)); stack_depot_init(); } @@ -51,7 +59,8 @@ int ref_tracker_free(struct ref_tracker_dir *dir, #else /* CONFIG_REF_TRACKER */ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, - unsigned int quarantine_count) + unsigned int quarantine_count, + ...) { } diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c index d4eb0929af8f96..2ffe79c90c1771 100644 --- a/lib/ref_tracker.c +++ b/lib/ref_tracker.c @@ -1,11 +1,16 @@ // SPDX-License-Identifier: GPL-2.0-or-later + +#define pr_fmt(fmt) "ref_tracker: " fmt + #include <linux/export.h> +#include <linux/list_sort.h> #include <linux/ref_tracker.h> #include <linux/slab.h> #include <linux/stacktrace.h> #include <linux/stackdepot.h> #define REF_TRACKER_STACK_ENTRIES 16 +#define STACK_BUF_SIZE 1024 struct ref_tracker { struct list_head head; /* anchor into dir->list or dir->quarantine */ @@ -14,24 +19,87 @@ struct ref_tracker { depot_stack_handle_t free_stack_handle; }; -void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, - unsigned int display_limit) +struct ref_tracker_dir_stats { + int total; + int count; + struct { + depot_stack_handle_t stack_handle; + unsigned int count; + } stacks[]; +}; + +static struct ref_tracker_dir_stats * +ref_tracker_get_stats(struct ref_tracker_dir *dir, unsigned int limit) { + struct ref_tracker_dir_stats *stats; struct ref_tracker *tracker; - unsigned int i = 0; - lockdep_assert_held(&dir->lock); + stats = kmalloc(struct_size(stats, stacks, limit), + GFP_NOWAIT | __GFP_NOWARN); + if (!stats) + return ERR_PTR(-ENOMEM); + stats->total = 0; + stats->count = 0; list_for_each_entry(tracker, &dir->list, head) { - if (i < display_limit) { - pr_err("leaked reference.\n"); - if (tracker->alloc_stack_handle) - stack_depot_print(tracker->alloc_stack_handle); - i++; - } else { - break; + depot_stack_handle_t stack = tracker->alloc_stack_handle; + int i; + + ++stats->total; + for (i = 0; i < stats->count; ++i) + if (stats->stacks[i].stack_handle == stack) + break; + if (i >= limit) + continue; + if (i >= stats->count) { + stats->stacks[i].stack_handle = stack; + stats->stacks[i].count = 0; + ++stats->count; } + ++stats->stacks[i].count; + } + + return stats; +} + +void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir, + unsigned int display_limit) +{ + struct ref_tracker_dir_stats *stats; + unsigned int i = 0, skipped; + depot_stack_handle_t stack; + char *sbuf; + + lockdep_assert_held(&dir->lock); + + if (list_empty(&dir->list)) + return; + + stats = ref_tracker_get_stats(dir, display_limit); + if (IS_ERR(stats)) { + pr_err("%s@%pK: couldn't get stats, error %pe\n", + dir->name, dir, stats); + return; } + + sbuf = kmalloc(STACK_BUF_SIZE, GFP_NOWAIT | __GFP_NOWARN); + + for (i = 0, skipped = stats->total; i < stats->count; ++i) { + stack = stats->stacks[i].stack_handle; + if (sbuf && !stack_depot_snprint(stack, sbuf, STACK_BUF_SIZE, 4)) + sbuf[0] = 0; + pr_err("%s@%pK has %d/%d users at\n%s\n", dir->name, dir, + stats->stacks[i].count, stats->total, sbuf); + skipped -= stats->stacks[i].count; + } + + if (skipped) + pr_err("%s@%pK skipped reports about %d/%d users.\n", + dir->name, dir, skipped, stats->total); + + kfree(sbuf); + + kfree(stats); } EXPORT_SYMBOL(ref_tracker_dir_print_locked);