Re: [kbuild-all] Re: fs/f2fs/gc.c:622:12: warning: stack frame size of 3056 bytes in function 'get_victim_by_default'

From: Rong Chen
Date: Wed Jan 13 2021 - 01:04:47 EST




On 1/11/21 4:23 PM, Chao Yu wrote:
Hello,

Thanks for the report.

I replied for your previous report [1], could you please check that?

[1] https://lore.kernel.org/lkml/8a8ef6b8-84c2-abfe-e758-2fa52a989c72@xxxxxxxxxx/

That says, in my environment, get_victim_by_default()'s frame size is less than
512 bytes, and also after going through related code, I don't see any obvious
large stack size usage.

Is that issue a powerpc specified issue?

Hi Chao,

The issue can be found on arch mips too:

fs/f2fs/gc.c:622:12: warning: stack frame size of 1672 bytes in function 'get_victim_by_default' [-Wframe-larger-than=]

static int get_victim_by_default(struct f2fs_sb_info *sbi,
^
1 warning generated.




Could you help to verify powerpc compiling with -Wframe-larger-than=512 after
reverting that atgc patch? I mean whether get_victim_by_default() already have
large frame size before applying atgc patch (commit 093749e296e2)?

After reverting commit 093749e29 and set -Wframe-larger-than=512, the warning is

fs/f2fs/gc.c:325:12: warning: stack frame size of 912 bytes in function 'get_victim_by_default' [-Wframe-larger-than=]
static int get_victim_by_default(struct f2fs_sb_info *sbi,

Best Regards,
Rong Chen


On 2021/1/9 21:18, kernel test robot wrote:
Hi Chao,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   996e435fd401de35df62ac943ab9402cfe85c430
commit: 093749e296e29a4b0162eb925a6701a01e8c9a98 f2fs: support age threshold based garbage collection
date:   4 months ago
config: powerpc-randconfig-r033-20210109 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project bc556e5685c0f97e79fb7b3c6f15cc5062db8e36)
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 powerpc cross compiling tool for clang build
         # apt-get install binutils-powerpc-linux-gnu
         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=093749e296e29a4b0162eb925a6701a01e8c9a98
         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
         git fetch --no-tags linus master
         git checkout 093749e296e29a4b0162eb925a6701a01e8c9a98
         # save the attached .config to linux build tree
         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

    arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
    DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                    __do_##name al;                                 \
                    ^~~~~~~~~~~~~~
    <scratch space>:182:1: note: expanded from here
    __do_insw
    ^
    arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw'
    #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
~~~~~~~~~~~~~~~~~~~~~^
    In file included from fs/f2fs/gc.c:10:
    In file included from include/linux/backing-dev.h:15:
    In file included from include/linux/blkdev.h:13:
    In file included from include/linux/pagemap.h:11:
    In file included from include/linux/highmem.h:10:
    In file included from include/linux/hardirq.h:10:
    In file included from arch/powerpc/include/asm/hardirq.h:6:
    In file included from include/linux/irq.h:20:
    In file included from include/linux/io.h:13:
    In file included from arch/powerpc/include/asm/io.h:604:
    arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
    DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                    __do_##name al;                                 \
                    ^~~~~~~~~~~~~~
    <scratch space>:184:1: note: expanded from here
    __do_insl
    ^
    arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl'
    #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
~~~~~~~~~~~~~~~~~~~~~^
    In file included from fs/f2fs/gc.c:10:
    In file included from include/linux/backing-dev.h:15:
    In file included from include/linux/blkdev.h:13:
    In file included from include/linux/pagemap.h:11:
    In file included from include/linux/highmem.h:10:
    In file included from include/linux/hardirq.h:10:
    In file included from arch/powerpc/include/asm/hardirq.h:6:
    In file included from include/linux/irq.h:20:
    In file included from include/linux/io.h:13:
    In file included from arch/powerpc/include/asm/io.h:604:
    arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
    DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                    __do_##name al;                                 \
                    ^~~~~~~~~~~~~~
    <scratch space>:186:1: note: expanded from here
    __do_outsb
    ^
    arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb'
    #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
~~~~~~~~~~~~~~~~~~~~~^
    In file included from fs/f2fs/gc.c:10:
    In file included from include/linux/backing-dev.h:15:
    In file included from include/linux/blkdev.h:13:
    In file included from include/linux/pagemap.h:11:
    In file included from include/linux/highmem.h:10:
    In file included from include/linux/hardirq.h:10:
    In file included from arch/powerpc/include/asm/hardirq.h:6:
    In file included from include/linux/irq.h:20:
    In file included from include/linux/io.h:13:
    In file included from arch/powerpc/include/asm/io.h:604:
    arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
    DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                    __do_##name al;                                 \
                    ^~~~~~~~~~~~~~
    <scratch space>:188:1: note: expanded from here
    __do_outsw
    ^
    arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
    #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
~~~~~~~~~~~~~~~~~~~~~^
    In file included from fs/f2fs/gc.c:10:
    In file included from include/linux/backing-dev.h:15:
    In file included from include/linux/blkdev.h:13:
    In file included from include/linux/pagemap.h:11:
    In file included from include/linux/highmem.h:10:
    In file included from include/linux/hardirq.h:10:
    In file included from arch/powerpc/include/asm/hardirq.h:6:
    In file included from include/linux/irq.h:20:
    In file included from include/linux/io.h:13:
    In file included from arch/powerpc/include/asm/io.h:604:
    arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
    DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                    __do_##name al;                                 \
                    ^~~~~~~~~~~~~~
    <scratch space>:190:1: note: expanded from here
    __do_outsl
    ^
    arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
    #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
~~~~~~~~~~~~~~~~~~~~~^
fs/f2fs/gc.c:622:12: warning: stack frame size of 3056 bytes in function 'get_victim_by_default' [-Wframe-larger-than=]
    static int get_victim_by_default(struct f2fs_sb_info *sbi,
               ^
    13 warnings generated.


vim +/get_victim_by_default +622 fs/f2fs/gc.c

093749e296e29a4 Chao Yu       2020-08-04  613
0a8165d7c2cf139 Jaegeuk Kim   2012-11-29  614  /*
111d2495a8a8fbd Masanari Iida 2013-03-19  615   * This function is called from two paths.
7bc0900347e069a Jaegeuk Kim   2012-11-02  616   * One is garbage collection and the other is SSR segment selection.
7bc0900347e069a Jaegeuk Kim   2012-11-02  617   * When it is called during GC, it just gets a victim segment
7bc0900347e069a Jaegeuk Kim   2012-11-02  618   * and it does not remove it from dirty seglist.
7bc0900347e069a Jaegeuk Kim   2012-11-02  619   * When it is called from SSR segment selection, it finds a segment
7bc0900347e069a Jaegeuk Kim   2012-11-02  620   * which has minimum valid blocks and removes it from dirty seglist.
7bc0900347e069a Jaegeuk Kim   2012-11-02  621   */
7bc0900347e069a Jaegeuk Kim   2012-11-02 @622  static int get_victim_by_default(struct f2fs_sb_info *sbi,
093749e296e29a4 Chao Yu       2020-08-04  623 unsigned int *result, int gc_type, int type,
093749e296e29a4 Chao Yu       2020-08-04  624              char alloc_mode, unsigned long long age)
7bc0900347e069a Jaegeuk Kim   2012-11-02  625  {
7bc0900347e069a Jaegeuk Kim   2012-11-02  626      struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  627      struct sit_info *sm = SIT_I(sbi);
7bc0900347e069a Jaegeuk Kim   2012-11-02  628      struct victim_sel_policy p;
3fa565039e3338f Sheng Yong    2016-09-29  629      unsigned int secno, last_victim;
04f0b2eaa3b3ee2 Qiuyang Sun   2019-06-05  630      unsigned int last_segment;
093749e296e29a4 Chao Yu       2020-08-04  631      unsigned int nsearched;
093749e296e29a4 Chao Yu       2020-08-04  632      bool is_atgc;
97767500781fae9 Qilong Zhang  2020-06-28  633      int ret = 0;
7bc0900347e069a Jaegeuk Kim   2012-11-02  634
210f41bc048263d Chao Yu       2014-09-15  635 mutex_lock(&dirty_i->seglist_lock);
04f0b2eaa3b3ee2 Qiuyang Sun   2019-06-05  636      last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
210f41bc048263d Chao Yu       2014-09-15  637
7bc0900347e069a Jaegeuk Kim   2012-11-02  638      p.alloc_mode = alloc_mode;
093749e296e29a4 Chao Yu       2020-08-04  639      p.age = age;
093749e296e29a4 Chao Yu       2020-08-04  640 p.age_threshold = sbi->am.age_threshold;
7bc0900347e069a Jaegeuk Kim   2012-11-02  641
093749e296e29a4 Chao Yu       2020-08-04  642  retry:
093749e296e29a4 Chao Yu       2020-08-04  643 select_policy(sbi, gc_type, type, &p);
7bc0900347e069a Jaegeuk Kim   2012-11-02  644      p.min_segno = NULL_SEGNO;
093749e296e29a4 Chao Yu       2020-08-04  645      p.oldest_age = 0;
3fa565039e3338f Sheng Yong    2016-09-29  646      p.min_cost = get_max_cost(sbi, &p);
7bc0900347e069a Jaegeuk Kim   2012-11-02  647
093749e296e29a4 Chao Yu       2020-08-04  648      is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
093749e296e29a4 Chao Yu       2020-08-04  649      nsearched = 0;
093749e296e29a4 Chao Yu       2020-08-04  650
093749e296e29a4 Chao Yu       2020-08-04  651      if (is_atgc)
093749e296e29a4 Chao Yu       2020-08-04  652 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
093749e296e29a4 Chao Yu       2020-08-04  653
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  654      if (*result != NULL_SEGNO) {
97767500781fae9 Qilong Zhang  2020-06-28  655          if (!get_valid_blocks(sbi, *result, false)) {
97767500781fae9 Qilong Zhang  2020-06-28  656              ret = -ENODATA;
97767500781fae9 Qilong Zhang  2020-06-28  657              goto out;
97767500781fae9 Qilong Zhang  2020-06-28  658          }
97767500781fae9 Qilong Zhang  2020-06-28  659
97767500781fae9 Qilong Zhang  2020-06-28  660          if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
97767500781fae9 Qilong Zhang  2020-06-28  661              ret = -EBUSY;
97767500781fae9 Qilong Zhang  2020-06-28  662          else
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  663 p.min_segno = *result;
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  664          goto out;
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  665      }
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  666
97767500781fae9 Qilong Zhang  2020-06-28  667      ret = -ENODATA;
3342bb303bf48dd Chao Yu       2015-10-05  668      if (p.max_search == 0)
3342bb303bf48dd Chao Yu       2015-10-05  669          goto out;
3342bb303bf48dd Chao Yu       2015-10-05  670
e3080b0120a15e6 Chao Yu       2018-10-24  671      if (__is_large_section(sbi) && p.alloc_mode == LFS) {
e3080b0120a15e6 Chao Yu       2018-10-24  672          if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
e3080b0120a15e6 Chao Yu       2018-10-24  673 p.min_segno = sbi->next_victim_seg[BG_GC];
e3080b0120a15e6 Chao Yu       2018-10-24  674 *result = p.min_segno;
e3080b0120a15e6 Chao Yu       2018-10-24  675 sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
e3080b0120a15e6 Chao Yu       2018-10-24  676              goto got_result;
e3080b0120a15e6 Chao Yu       2018-10-24  677          }
e3080b0120a15e6 Chao Yu       2018-10-24  678          if (gc_type == FG_GC &&
e3080b0120a15e6 Chao Yu       2018-10-24  679 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
e3080b0120a15e6 Chao Yu       2018-10-24  680 p.min_segno = sbi->next_victim_seg[FG_GC];
e3080b0120a15e6 Chao Yu       2018-10-24  681 *result = p.min_segno;
e3080b0120a15e6 Chao Yu       2018-10-24  682 sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
e3080b0120a15e6 Chao Yu       2018-10-24  683              goto got_result;
e3080b0120a15e6 Chao Yu       2018-10-24  684          }
e3080b0120a15e6 Chao Yu       2018-10-24  685      }
e3080b0120a15e6 Chao Yu       2018-10-24  686
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  687      last_victim = sm->last_victim[p.gc_mode];
7bc0900347e069a Jaegeuk Kim   2012-11-02  688      if (p.alloc_mode == LFS && gc_type == FG_GC) {
7bc0900347e069a Jaegeuk Kim   2012-11-02  689 p.min_segno = check_bg_victims(sbi);
7bc0900347e069a Jaegeuk Kim   2012-11-02  690          if (p.min_segno != NULL_SEGNO)
7bc0900347e069a Jaegeuk Kim   2012-11-02  691              goto got_it;
7bc0900347e069a Jaegeuk Kim   2012-11-02  692      }
7bc0900347e069a Jaegeuk Kim   2012-11-02  693
7bc0900347e069a Jaegeuk Kim   2012-11-02  694      while (1) {
da52f8ade40b032 Jack Qiu      2020-06-18  695          unsigned long cost, *dirty_bitmap;
da52f8ade40b032 Jack Qiu      2020-06-18  696          unsigned int unit_no, segno;
da52f8ade40b032 Jack Qiu      2020-06-18  697
da52f8ade40b032 Jack Qiu      2020-06-18  698 dirty_bitmap = p.dirty_bitmap;
da52f8ade40b032 Jack Qiu      2020-06-18  699          unit_no = find_next_bit(dirty_bitmap,
da52f8ade40b032 Jack Qiu      2020-06-18  700 last_segment / p.ofs_unit,
da52f8ade40b032 Jack Qiu      2020-06-18  701 p.offset / p.ofs_unit);
da52f8ade40b032 Jack Qiu      2020-06-18  702          segno = unit_no * p.ofs_unit;
a43f7ec327b0d86 Chao Yu       2015-10-05  703          if (segno >= last_segment) {
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  704              if (sm->last_victim[p.gc_mode]) {
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  705 last_segment =
e066b83c9b40f3a Jaegeuk Kim   2017-04-13 706                      sm->last_victim[p.gc_mode];
e066b83c9b40f3a Jaegeuk Kim   2017-04-13  707 sm->last_victim[p.gc_mode] = 0;
7bc0900347e069a Jaegeuk Kim   2012-11-02  708 p.offset = 0;
7bc0900347e069a Jaegeuk Kim   2012-11-02  709 continue;
7bc0900347e069a Jaegeuk Kim   2012-11-02  710              }
7bc0900347e069a Jaegeuk Kim   2012-11-02  711 break;
7bc0900347e069a Jaegeuk Kim   2012-11-02  712          }
a57e564d14d9d12 Jin Xu        2013-09-13  713
a57e564d14d9d12 Jin Xu        2013-09-13  714          p.offset = segno + p.ofs_unit;
688159b6db47a9e Fan Li        2016-02-03  715 nsearched++;
688159b6db47a9e Fan Li        2016-02-03  716

:::::: The code at line 622 was first introduced by commit
:::::: 7bc0900347e069a1676d28ad6f98cafaf8cfd6e9 f2fs: add garbage collection functions

:::::: TO: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
:::::: CC: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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