diff options
| -rw-r--r-- | Documentation/mm/page_owner.rst | 5 | ||||
| -rw-r--r-- | mm/page_owner.c | 24 |
2 files changed, 26 insertions, 3 deletions
diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst index f5c954afe97c..f18fd8907049 100644 --- a/Documentation/mm/page_owner.rst +++ b/Documentation/mm/page_owner.rst @@ -94,6 +94,11 @@ Usage Page allocated via order XXX, ... PFN XXX ... // Detailed stack + By default, it will do full pfn dump, to start with a given pfn, + page_owner supports fseek. + + FILE *fp = fopen("/sys/kernel/debug/page_owner", "r"); + fseek(fp, pfn_start, SEEK_SET); The ``page_owner_sort`` tool ignores ``PFN`` rows, puts the remaining rows in buf, uses regexp to extract the page order value, counts the times diff --git a/mm/page_owner.c b/mm/page_owner.c index 72839a606e22..90023f938c19 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -516,8 +516,10 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) return -EINVAL; page = NULL; - pfn = min_low_pfn + *ppos; - + if (*ppos == 0) + pfn = min_low_pfn; + else + pfn = *ppos; /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */ while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) pfn++; @@ -588,7 +590,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) goto ext_put_continue; /* Record the next PFN to read in the file offset */ - *ppos = (pfn - min_low_pfn) + 1; + *ppos = pfn + 1; page_owner_tmp = *page_owner; page_ext_put(page_ext); @@ -601,6 +603,21 @@ ext_put_continue: return 0; } +static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig) +{ + switch (orig) { + case SEEK_SET: + file->f_pos = offset; + break; + case SEEK_CUR: + file->f_pos += offset; + break; + default: + return -EINVAL; + } + return file->f_pos; +} + static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) { unsigned long pfn = zone->zone_start_pfn; @@ -693,6 +710,7 @@ static void init_early_allocated_pages(void) static const struct file_operations proc_page_owner_operations = { .read = read_page_owner, + .llseek = lseek_page_owner, }; static int __init pageowner_init(void) |