| Message ID | 20240215215907.20121-7-osalvador@suse.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | page_owner: print stacks and their outstanding allocations | expand |
Hi On 2024/2/16 5:59, Oscar Salvador wrote: > We want to be able to filter out the stacks based on a threshold we can > can tune. > By writing to 'count_threshold' file, we can adjust the threshold value. > > Signed-off-by: Oscar Salvador <osalvador@suse.de> > Reviewed-by: Vlastimil Babka <vbabka@suse.cz> > --- > mm/page_owner.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/mm/page_owner.c b/mm/page_owner.c > index e99fbf822dd6..e56c1e92eccf 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -846,6 +846,8 @@ static void *stack_next(struct seq_file *m, void *v, loff_t *ppos) > return stack; > } > > +static unsigned long page_owner_stack_threshold; > + > static int stack_print(struct seq_file *m, void *v) > { > int i, stack_count; > @@ -858,7 +860,8 @@ static int stack_print(struct seq_file *m, void *v) > entries = stack_record->entries; > stack_count = refcount_read(&stack_record->count) - 1; > > - if (!nr_entries || nr_entries < 0 || stack_count < 1) > + if (!nr_entries || nr_entries < 0 || stack_count < 1 || > + stack_count < page_owner_stack_threshold) > return 0; > > for (i = 0; i < nr_entries; i++) > @@ -891,6 +894,22 @@ static const struct file_operations page_owner_stack_operations = { > .release = seq_release, > }; > > +static int page_owner_threshold_get(void *data, u64 *val) > +{ > + *val = READ_ONCE(page_owner_stack_threshold); > + return 0; > +} > + > +static int page_owner_threshold_set(void *data, u64 val) > +{ > + WRITE_ONCE(page_owner_stack_threshold, val); > + return 0; > +} no need READ/WRITE_ONCE between get/set, since simple_attr_read/write() with a mutex, but set and stack_print could date race > + > +DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get, > + &page_owner_threshold_set, "%llu"); %llu\n" In addition, since we have a stack_list, could we add a new feature to dump stack info with threshold with OOM notifier, because many users directly call alloc_page family, which makes it too difficult to debug during OOM. Thanks > + > + > static int __init pageowner_init(void) > { > struct dentry *dir; > @@ -905,6 +924,8 @@ static int __init pageowner_init(void) > dir = debugfs_create_dir("page_owner_stacks", NULL); > debugfs_create_file("show_stacks", 0400, dir, NULL, > &page_owner_stack_operations); > + debugfs_create_file("count_threshold", 0600, dir, NULL, > + &proc_page_owner_threshold); > > return 0; > }
diff --git a/mm/page_owner.c b/mm/page_owner.c index e99fbf822dd6..e56c1e92eccf 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -846,6 +846,8 @@ static void *stack_next(struct seq_file *m, void *v, loff_t *ppos) return stack; } +static unsigned long page_owner_stack_threshold; + static int stack_print(struct seq_file *m, void *v) { int i, stack_count; @@ -858,7 +860,8 @@ static int stack_print(struct seq_file *m, void *v) entries = stack_record->entries; stack_count = refcount_read(&stack_record->count) - 1; - if (!nr_entries || nr_entries < 0 || stack_count < 1) + if (!nr_entries || nr_entries < 0 || stack_count < 1 || + stack_count < page_owner_stack_threshold) return 0; for (i = 0; i < nr_entries; i++) @@ -891,6 +894,22 @@ static const struct file_operations page_owner_stack_operations = { .release = seq_release, }; +static int page_owner_threshold_get(void *data, u64 *val) +{ + *val = READ_ONCE(page_owner_stack_threshold); + return 0; +} + +static int page_owner_threshold_set(void *data, u64 val) +{ + WRITE_ONCE(page_owner_stack_threshold, val); + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get, + &page_owner_threshold_set, "%llu"); + + static int __init pageowner_init(void) { struct dentry *dir; @@ -905,6 +924,8 @@ static int __init pageowner_init(void) dir = debugfs_create_dir("page_owner_stacks", NULL); debugfs_create_file("show_stacks", 0400, dir, NULL, &page_owner_stack_operations); + debugfs_create_file("count_threshold", 0600, dir, NULL, + &proc_page_owner_threshold); return 0; }