There is usage to dump a given cma region page_owner
instead of all page's.
This change allows to specify a ppos as start_pfn
by fseek.
Any invalid ppos will be skipped, so it did not
broken the origin dump feature.
Suggested-by: Vlastimil Babka <[email protected]>
Signed-off-by: Kassey Li <[email protected]>
---
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..c1a54e0e07dc 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;
}
+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)
--
2.17.1
Hi Kassey,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.0-rc1 next-20220815]
[cannot apply to akpm-mm/mm-everything]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Kassey-Li/mm-page_owner-c-add-llseek-for-page_owner/20220815-143155
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
config: hexagon-randconfig-r041-20220814 (https://download.01.org/0day-ci/archive/20220815/[email protected]/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6afcc4a459ead8809a0d6d9b4bf7b64bcc13582b)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/f9ef28f8ab55cdd176ab5ce7ad606ca45b4dbcc0
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Kassey-Li/mm-page_owner-c-add-llseek-for-page_owner/20220815-143155
git checkout f9ef28f8ab55cdd176ab5ce7ad606ca45b4dbcc0
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> mm/page_owner.c:575:8: warning: no previous prototype for function 'lseek_page_owner' [-Wmissing-prototypes]
loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
^
mm/page_owner.c:575:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
^
static
1 warning generated.
vim +/lseek_page_owner +575 mm/page_owner.c
574
> 575 loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
576 {
577 switch (orig) {
578 case SEEK_SET:
579 file->f_pos = offset;
580 break;
581 case SEEK_CUR:
582 file->f_pos += offset;
583 break;
584 default:
585 return -EINVAL;
586 }
587 return file->f_pos;
588 }
589
--
0-DAY CI Kernel Test Service
https://01.org/lkp
Hi Kassey,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.0-rc1 next-20220815]
[cannot apply to akpm-mm/mm-everything]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Kassey-Li/mm-page_owner-c-add-llseek-for-page_owner/20220815-143155
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
config: sh-allmodconfig (https://download.01.org/0day-ci/archive/20220815/[email protected]/config)
compiler: sh4-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/f9ef28f8ab55cdd176ab5ce7ad606ca45b4dbcc0
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Kassey-Li/mm-page_owner-c-add-llseek-for-page_owner/20220815-143155
git checkout f9ef28f8ab55cdd176ab5ce7ad606ca45b4dbcc0
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sh SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
All warnings (new ones prefixed by >>):
>> mm/page_owner.c:575:8: warning: no previous prototype for 'lseek_page_owner' [-Wmissing-prototypes]
575 | loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
| ^~~~~~~~~~~~~~~~
vim +/lseek_page_owner +575 mm/page_owner.c
574
> 575 loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
576 {
577 switch (orig) {
578 case SEEK_SET:
579 file->f_pos = offset;
580 break;
581 case SEEK_CUR:
582 file->f_pos += offset;
583 break;
584 default:
585 return -EINVAL;
586 }
587 return file->f_pos;
588 }
589
--
0-DAY CI Kernel Test Service
https://01.org/lkp