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Date: Fri, 18 Feb 2022 11:11:24 +0100 From: Andrzej Hajda <andrzej.hajda@...el.com> To: Eric Dumazet <edumazet@...gle.com> CC: LKML <linux-kernel@...r.kernel.org>, <intel-gfx@...ts.freedesktop.org>, <dri-devel@...ts.freedesktop.org>, netdev <netdev@...r.kernel.org>, "Jani Nikula" <jani.nikula@...ux.intel.com>, Daniel Vetter <daniel@...ll.ch>, Lucas De Marchi <lucas.demarchi@...el.com>, Chris Wilson <chris.p.wilson@...el.com>, Dmitry Vyukov <dvyukov@...gle.com>, "Jakub Kicinski" <kuba@...nel.org> Subject: Re: [PATCH 3/9] lib/ref_tracker: __ref_tracker_dir_print improve printing On 17.02.2022 16:38, Eric Dumazet wrote: > On Thu, Feb 17, 2022 at 6:05 AM Andrzej Hajda <andrzej.hajda@...el.com> wrote: >> To improve readibility of ref_tracker printing following changes >> have been performed: >> - 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@...el.com> >> Reviewed-by: Chris Wilson <chris.p.wilson@...el.com> >> --- >> include/linux/ref_tracker.h | 15 ++++++++++++--- >> lib/ref_tracker.c | 28 ++++++++++++++++++++++------ >> 2 files changed, 34 insertions(+), 9 deletions(-) >> >> diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h >> index b9c968a716483..090230e5b485d 100644 >> --- a/include/linux/ref_tracker.h >> +++ b/include/linux/ref_tracker.h >> @@ -15,18 +15,26 @@ struct ref_tracker_dir { >> refcount_t untracked; >> 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); >> spin_lock_init(&dir->lock); >> dir->quarantine_avail = quarantine_count; >> refcount_set(&dir->untracked, 1); >> + strlcpy(dir->name, name, sizeof(dir->name)); >> stack_depot_init(); >> } >> >> @@ -47,7 +55,8 @@ 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 0e9c7d2828ccb..943cff08110e3 100644 >> --- a/lib/ref_tracker.c >> +++ b/lib/ref_tracker.c >> @@ -1,4 +1,7 @@ >> // 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> >> @@ -7,6 +10,7 @@ >> #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 */ >> @@ -26,31 +30,43 @@ static int ref_tracker_cmp(void *priv, const struct list_head *a, const struct l >> void __ref_tracker_dir_print(struct ref_tracker_dir *dir, >> unsigned int display_limit) >> { >> - unsigned int i = 0, count = 0; >> + unsigned int i = 0, count = 0, total = 0; >> struct ref_tracker *tracker; >> depot_stack_handle_t stack; >> + char *sbuf; >> >> lockdep_assert_held(&dir->lock); >> >> if (list_empty(&dir->list)) >> return; >> >> + sbuf = kmalloc(STACK_BUF_SIZE, GFP_NOWAIT); >> + >> + list_for_each_entry(tracker, &dir->list, head) >> + ++total; > Another iteration over a potential long list. > > You can count the @skipped number in the following iteration just fine. Skipped is already in 'count', but you are right with double looping> I can count total in the same loop, just forgot to merge loops during code evolution. Will be fixed. Regards Andrzej > int skipped = 0; > >> + >> list_sort(NULL, &dir->list, ref_tracker_cmp); >> >> list_for_each_entry(tracker, &dir->list, head) { >> - if (i++ >= display_limit) >> - break; >> if (!count++) >> stack = tracker->alloc_stack_handle; >> if (stack == tracker->alloc_stack_handle && >> !list_is_last(&tracker->head, &dir->list)) >> continue; >> + if (i++ >= display_limit) > skipped++; >> + continue; >> >> - pr_err("leaked %d references.\n", count); >> - if (stack) >> - stack_depot_print(stack); >> + 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, count, total, sbuf); >> count = 0; >> } >> + if (i > display_limit) >> + pr_err("%s@%pK skipped %d/%d reports with %d unique stacks.\n", >> + dir->name, dir, count, total, i - display_limit); >> + >> + kfree(sbuf); >> } >> EXPORT_SYMBOL(__ref_tracker_dir_print); >> >> -- >> 2.25.1 >>
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