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.
Signed-off-by: Kassey Li <[email protected]>
---
mm/page_owner.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/mm/page_owner.c b/mm/page_owner.c
index e4c6f3f1695b..f0bc75421de0 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -497,8 +497,8 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
return -EINVAL;
page = NULL;
- pfn = min_low_pfn + *ppos;
+ 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 +561,7 @@ 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 +570,21 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
return 0;
}
+loff_t llseek_page_owner(struct file *file, loff_t offset, int whence)
+{
+ loff_t retval = 0;
+ switch (whence) {
+ case SEEK_CUR:
+ case SEEK_SET:
+ file->f_pos = offset;
+ break;
+ default:
+ retval = -ENXIO;
+ }
+
+ return retval;
+}
+
static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
{
unsigned long pfn = zone->zone_start_pfn;
@@ -658,8 +673,11 @@ static void init_early_allocated_pages(void)
init_zones_in_node(pgdat);
}
+
+
static const struct file_operations proc_page_owner_operations = {
.read = read_page_owner,
+ .llseek = llseek_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 akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/Kassey-Li/mm-page_owner-c-add-llseek-for-page_owner/20220727-205617
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: arm64-randconfig-r025-20220727 (https://download.01.org/0day-ci/archive/20220728/[email protected]/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 8dfaecc4c24494337933aff9d9166486ca0949f1)
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
# install arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/5533df4120ec1703df71542154e8c5b0b21ddb10
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/20220727-205617
git checkout 5533df4120ec1703df71542154e8c5b0b21ddb10
# 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=arm64 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:573:8: warning: no previous prototype for function 'llseek_page_owner' [-Wmissing-prototypes]
loff_t llseek_page_owner(struct file *file, loff_t offset, int whence)
^
mm/page_owner.c:573:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
loff_t llseek_page_owner(struct file *file, loff_t offset, int whence)
^
static
1 warning generated.
vim +/llseek_page_owner +573 mm/page_owner.c
572
> 573 loff_t llseek_page_owner(struct file *file, loff_t offset, int whence)
574 {
575 loff_t retval = 0;
576 switch (whence) {
577 case SEEK_CUR:
578 case SEEK_SET:
579 file->f_pos = offset;
580 break;
581 default:
582 retval = -ENXIO;
583 }
584
585 return retval;
586 }
587
--
0-DAY CI Kernel Test Service
https://01.org/lkp