| Message ID | 20220901044249.4624-3-osalvador@suse.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | page_owner: print stacks and their counter | expand |
On 9/1/22 11:42 AM, Oscar Salvador wrote: > +static unsigned long last_stack = 0; This @last_stack can just be a static local variable in the new function you wrote, read_page_owner_stacks(), since no other functions use it. > +static ssize_t read_page_owner_stacks(struct file *file, char __user *buf, > + size_t count, loff_t *pos) > +{ > + char *kbuf; > + int ret = 0; > + > + count = min_t(size_t, count, PAGE_SIZE); > + kbuf = kmalloc(count, GFP_KERNEL); > + if (!kbuf) > + return ENOMEM; Missing a negative sign, return -ENOMEM; > + ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack); > + if (copy_to_user(buf, kbuf, ret)) > + ret = -EFAULT; > + > + if (!ret) > + last_stack = 0; > + > + kfree(kbuf); > + return ret; > +}
Hi Oscar,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.0-rc3]
[cannot apply to akpm-mm/mm-everything next-20220901]
[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/Oscar-Salvador/page_owner-print-stacks-and-their-counter/20220901-124408
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c5e4d5e99162ba8025d58a3af7ad103f155d2df7
config: s390-buildonly-randconfig-r001-20220901
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c55b41d5199d2394dd6cdb8f52180d8b81d809d4)
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 s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/18d3054fb57a70676be763adab8c8881a1baa504
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Oscar-Salvador/page_owner-print-stacks-and-their-counter/20220901-124408
git checkout 18d3054fb57a70676be763adab8c8881a1baa504
# 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=s390 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from lib/stackdepot.c:34:
In file included from include/linux/memblock.h:13:
In file included from arch/s390/include/asm/dma.h:5:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
^
In file included from lib/stackdepot.c:34:
In file included from include/linux/memblock.h:13:
In file included from arch/s390/include/asm/dma.h:5:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
^
In file included from lib/stackdepot.c:34:
In file included from include/linux/memblock.h:13:
In file included from arch/s390/include/asm/dma.h:5:
In file included from arch/s390/include/asm/io.h:75:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> lib/stackdepot.c:603:10: error: use of undeclared identifier 'STACK_HASH_SIZE'
if (i < STACK_HASH_SIZE)
^
12 warnings and 1 error generated.
vim +/STACK_HASH_SIZE +603 lib/stackdepot.c
568
569 int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos,
570 unsigned long *last_stack)
571 {
572 struct stack_record *stack = NULL, *last;
573 struct stack_record **stacks;
574 int i = *pos, ret = 0;
575
576 /* Continue from the last week if we have one */
577 if (*last_stack) {
578 last = (struct stack_record *)*last_stack;
579 stack = last->next;
580 } else {
581 new_table:
582 stacks = &stack_table[i];
583 stack = (struct stack_record *)stacks;
584 }
585
586 for (; stack; stack = stack->next) {
587 if (!stack->size || stack->size < 0 ||
588 stack->size > size || stack->handle.valid != 1 ||
589 refcount_read(&stack->count) < 1)
590 continue;
591
592 ret += stack_trace_snprint(buf, size, stack->entries, stack->size, 0);
593 ret += scnprintf(buf + ret, size - ret, "stack count: %d\n\n",
594 refcount_read(&stack->count));
595 *last_stack = (unsigned long)stack;
596 return ret;
597 }
598
599 i++;
600 *pos = i;
601
602 /* Keep looking all tables for valid stacks */
> 603 if (i < STACK_HASH_SIZE)
Hi Oscar,
I love your patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.0-rc3]
[cannot apply to akpm-mm/mm-everything next-20220901]
[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/Oscar-Salvador/page_owner-print-stacks-and-their-counter/20220901-124408
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c5e4d5e99162ba8025d58a3af7ad103f155d2df7
config: arc-randconfig-r043-20220901 (https://download.01.org/0day-ci/archive/20220902/202209020818.s1RIxKyP-lkp@intel.com/config)
compiler: arc-elf-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/18d3054fb57a70676be763adab8c8881a1baa504
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Oscar-Salvador/page_owner-print-stacks-and-their-counter/20220901-124408
git checkout 18d3054fb57a70676be763adab8c8881a1baa504
# 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=arc SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
lib/stackdepot.c: In function 'stack_depot_print_stacks_threshold':
>> lib/stackdepot.c:603:17: error: 'STACK_HASH_SIZE' undeclared (first use in this function); did you mean 'STACK_HASH_SEED'?
603 | if (i < STACK_HASH_SIZE)
| ^~~~~~~~~~~~~~~
| STACK_HASH_SEED
lib/stackdepot.c:603:17: note: each undeclared identifier is reported only once for each function it appears in
vim +603 lib/stackdepot.c
568
569 int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos,
570 unsigned long *last_stack)
571 {
572 struct stack_record *stack = NULL, *last;
573 struct stack_record **stacks;
574 int i = *pos, ret = 0;
575
576 /* Continue from the last week if we have one */
577 if (*last_stack) {
578 last = (struct stack_record *)*last_stack;
579 stack = last->next;
580 } else {
581 new_table:
582 stacks = &stack_table[i];
583 stack = (struct stack_record *)stacks;
584 }
585
586 for (; stack; stack = stack->next) {
587 if (!stack->size || stack->size < 0 ||
588 stack->size > size || stack->handle.valid != 1 ||
589 refcount_read(&stack->count) < 1)
590 continue;
591
592 ret += stack_trace_snprint(buf, size, stack->entries, stack->size, 0);
593 ret += scnprintf(buf + ret, size - ret, "stack count: %d\n\n",
594 refcount_read(&stack->count));
595 *last_stack = (unsigned long)stack;
596 return ret;
597 }
598
599 i++;
600 *pos = i;
601
602 /* Keep looking all tables for valid stacks */
> 603 if (i < STACK_HASH_SIZE)
On Thu, Sep 01, 2022 at 03:16:44PM +0700, Ammar Faizi wrote: > On 9/1/22 11:42 AM, Oscar Salvador wrote: > > +static unsigned long last_stack = 0; > > This @last_stack can just be a static local variable in the new > function you wrote, read_page_owner_stacks(), since no other > functions use it. We could certainly do that. > > > +static ssize_t read_page_owner_stacks(struct file *file, char __user *buf, > > + size_t count, loff_t *pos) > > +{ > > + char *kbuf; > > + int ret = 0; > > + > > + count = min_t(size_t, count, PAGE_SIZE); > > + kbuf = kmalloc(count, GFP_KERNEL); > > + if (!kbuf) > > + return ENOMEM; > > Missing a negative sign, return -ENOMEM; Oh yes, I overlooked that. Thanks!
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index 5ee0cf5be88f..20f62039f23a 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -25,6 +25,8 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, gfp_t gfp_flags, bool can_alloc, stack_action_t action); void stack_depot_dec_count(depot_stack_handle_t handle); +int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos, + unsigned long *last_stack); /* * Every user of stack depot has to call stack_depot_init() during its own init diff --git a/lib/stackdepot.c b/lib/stackdepot.c index aeb59d3557e2..3090ae0f3958 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -526,3 +526,43 @@ depot_stack_handle_t stack_depot_save_action(unsigned long *entries, return __stack_depot_save(entries, nr_entries, alloc_flags, true, action); } EXPORT_SYMBOL_GPL(stack_depot_save_action); + +int stack_depot_print_stacks_threshold(char *buf, size_t size, loff_t *pos, + unsigned long *last_stack) +{ + struct stack_record *stack = NULL, *last; + struct stack_record **stacks; + int i = *pos, ret = 0; + + /* Continue from the last week if we have one */ + if (*last_stack) { + last = (struct stack_record *)*last_stack; + stack = last->next; + } else { +new_table: + stacks = &stack_table[i]; + stack = (struct stack_record *)stacks; + } + + for (; stack; stack = stack->next) { + if (!stack->size || stack->size < 0 || + stack->size > size || stack->handle.valid != 1 || + refcount_read(&stack->count) < 1) + continue; + + ret += stack_trace_snprint(buf, size, stack->entries, stack->size, 0); + ret += scnprintf(buf + ret, size - ret, "stack count: %d\n\n", + refcount_read(&stack->count)); + *last_stack = (unsigned long)stack; + return ret; + } + + i++; + *pos = i; + + /* Keep looking all tables for valid stacks */ + if (i < STACK_HASH_SIZE) + goto new_table; + + return 0; +} diff --git a/mm/page_owner.c b/mm/page_owner.c index 794f346d7520..8c67c7eb2451 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -43,6 +43,8 @@ static depot_stack_handle_t early_handle; static void init_early_allocated_pages(void); +static unsigned long last_stack = 0; + static int __init early_page_owner_param(char *buf) { int ret = kstrtobool(buf, &page_owner_enabled); @@ -663,6 +665,32 @@ static void init_early_allocated_pages(void) init_zones_in_node(pgdat); } +static ssize_t read_page_owner_stacks(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + char *kbuf; + int ret = 0; + + count = min_t(size_t, count, PAGE_SIZE); + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return ENOMEM; + + ret += stack_depot_print_stacks_threshold(kbuf, count, pos, &last_stack); + if (copy_to_user(buf, kbuf, ret)) + ret = -EFAULT; + + if (!ret) + last_stack = 0; + + kfree(kbuf); + return ret; +} + +static const struct file_operations proc_page_owner_stacks = { + .read = read_page_owner_stacks, +}; + static const struct file_operations proc_page_owner_operations = { .read = read_page_owner, }; @@ -676,6 +704,8 @@ static int __init pageowner_init(void) debugfs_create_file("page_owner", 0400, NULL, NULL, &proc_page_owner_operations); + debugfs_create_file("page_owner_stacks", 0400, NULL, NULL, + &proc_page_owner_stacks); return 0; }
We might be only interested in knowing about stacks <-> count relationship, so instead of having to fiddle with page_owner output and screen through pfns, let us add a new file called 'page_owner_stacks' that does just that. By cating such file, we will get all the stacktraces followed by its counter (allocated - freed times), so we can have a more specific overview. Signed-off-by: Oscar Salvador <osalvador@suse.de> --- include/linux/stackdepot.h | 2 ++ lib/stackdepot.c | 40 ++++++++++++++++++++++++++++++++++++++ mm/page_owner.c | 30 ++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+)