| Message ID | 20220818022425.31056-1-quic_yingangl@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v9] mm/page_owner.c: add llseek for page_owner | expand |
On 8/18/22 04:24, Kassey Li wrote: > It is too slow to dump all the pages, in some usage we just want dump > a given start pfn, for example: CMA range or a single page. > > To speed up and save time, this change allows specify start pfn > by add llseek for page_onwer. > > Suggested-by: Vlastimil Babka <vbabka@suse.cz> > Signed-off-by: Kassey Li <quic_yingangl@quicinc.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> > --- > Documentation/mm/page_owner.rst | 5 +++++ > 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 e4c6f3f1695b..25720d81bc26 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -497,8 +497,10 @@ 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++; > @@ -561,7 +563,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) > continue; > > /* Record the next PFN to read in the file offset */ > - *ppos = (pfn - min_low_pfn) + 1; > + *ppos = pfn + 1; > > return print_page_owner(buf, count, pfn, page, > page_owner, handle); > @@ -570,6 +572,21 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) > 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; > @@ -660,6 +677,7 @@ 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)
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 e4c6f3f1695b..25720d81bc26 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -497,8 +497,10 @@ 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++; @@ -561,7 +563,7 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) continue; /* Record the next PFN to read in the file offset */ - *ppos = (pfn - min_low_pfn) + 1; + *ppos = pfn + 1; return print_page_owner(buf, count, pfn, page, page_owner, handle); @@ -570,6 +572,21 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) 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; @@ -660,6 +677,7 @@ 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)
It is too slow to dump all the pages, in some usage we just want dump a given start pfn, for example: CMA range or a single page. To speed up and save time, this change allows specify start pfn by add llseek for page_onwer. Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Kassey Li <quic_yingangl@quicinc.com> --- Documentation/mm/page_owner.rst | 5 +++++ mm/page_owner.c | 24 +++++++++++++++++++++--- 2 files changed, 26 insertions(+), 3 deletions(-)