| Message ID | 20230224-track_gt-v4-2-464e8ab4c9ab@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: use ref_tracker library for tracking wakerefs | expand |
Hi Andrzej, looks good, few comments below, On Mon, Mar 06, 2023 at 05:31:58PM +0100, Andrzej Hajda wrote: > To improve readability of ref_tracker printing following changes > have been performed: > - reports are printed per stack_handle - log is more compact, > - added display name for ref_tracker_dir, > - stack trace is printed indented, in the same printk call, > - total number of references is printed every time, > - print info about dropped references. nit: I think you can do better with the log :) > Signed-off-by: Andrzej Hajda <andrzej.hajda@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 3e9e9df2a41f5f..a2cf1f6309adb2 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 I thought only Linus was allowed to use '//' :) > +#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) [...] > +void __ref_tracker_dir_print(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); what if sbuf is NULL? > + skipped -= stats->stacks[i].count; > + } > + > + if (skipped) is skipped used to double check whether stats->count is equal to all the stacks[].conunts? What are the cases when skipped is > 0? Andi > + 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); > > > -- > 2.34.1
On 20.03.2023 00:11, Andi Shyti wrote: > Hi Andrzej, > > looks good, few comments below, > > On Mon, Mar 06, 2023 at 05:31:58PM +0100, Andrzej Hajda wrote: >> To improve readability of ref_tracker printing following changes >> have been performed: >> - reports are printed per stack_handle - log is more compact, >> - added display name for ref_tracker_dir, >> - stack trace is printed indented, in the same printk call, >> - total number of references is printed every time, >> - print info about dropped references. > > nit: I think you can do better with the log :) > >> Signed-off-by: Andrzej Hajda <andrzej.hajda@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 3e9e9df2a41f5f..a2cf1f6309adb2 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 > > I thought only Linus was allowed to use '//' :) > >> +#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) > > [...] > >> +void __ref_tracker_dir_print(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); > > what if sbuf is NULL? Then "(NULL)" will be printed, I suspect it will occur only on very rare occasions. > >> + skipped -= stats->stacks[i].count; >> + } >> + >> + if (skipped) > > is skipped used to double check whether stats->count is equal to > all the stacks[].conunts? What are the cases when skipped is > 0? There is display_limit parameter, so the function prints up to display_limit reports, and brief summary on remaining ones - the skipped ones. Regards Andrzej > > Andi > >> + 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); >> >> >> -- >> 2.34.1
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h index 3e9e9df2a41f5f..a2cf1f6309adb2 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 5e9f90bbf771b0..ab1253fde244ea 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(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(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);
To improve readability of ref_tracker printing following changes have been performed: - reports are printed per stack_handle - log is more compact, - added display name for ref_tracker_dir, - stack trace is printed indented, in the same printk call, - total number of references is printed every time, - print info about dropped references. Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> --- include/linux/ref_tracker.h | 15 ++++++-- lib/ref_tracker.c | 90 +++++++++++++++++++++++++++++++++++++++------ 2 files changed, 91 insertions(+), 14 deletions(-)