| Message ID | 163969850295.20885.4255989535187500085.stgit@noble.brown (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Repair SWAP-over-NFS | expand |
Hi NeilBrown,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on cifs/for-next]
[also build test ERROR on axboe-block/for-next rostedt-trace/for-next linus/master v5.16-rc5]
[cannot apply to trondmy-nfs/linux-next hnaz-mm/master mszeredi-vfs/overlayfs-next next-20211216]
[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]
url: https://github.com/0day-ci/linux/commits/NeilBrown/Repair-SWAP-over-NFS/20211217-075659
base: git://git.samba.org/sfrench/cifs-2.6.git for-next
config: arm-randconfig-r006-20211216 (https://download.01.org/0day-ci/archive/20211217/202112171635.JUIRMzHQ-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 9043c3d65b11b442226015acfbf8167684586cfa)
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 arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://github.com/0day-ci/linux/commit/a8e1b1ffec6ade1545df519d254eae0400b7ec37
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review NeilBrown/Repair-SWAP-over-NFS/20211217-075659
git checkout a8e1b1ffec6ade1545df519d254eae0400b7ec37
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
^
mm/vmscan.c:1480:20: note: did you mean 'swp_swap_info'?
include/linux/swap.h:487:40: note: 'swp_swap_info' declared here
static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry)
^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
~~~~~~~~~~~~~~~~~~~~ ^
include/linux/compiler.h:216:28: note: expanded from macro 'data_race'
__unqual_scalar_typeof(({ expr; })) __v = ({ \
^~~~
include/linux/compiler_types.h:291:13: note: expanded from macro '__unqual_scalar_typeof'
_Generic((x), \
^
>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
~~~~~~~~~~~~~~~~~~~~ ^
include/linux/compiler.h:216:28: note: expanded from macro 'data_race'
__unqual_scalar_typeof(({ expr; })) __v = ({ \
^~~~
include/linux/compiler_types.h:298:15: note: expanded from macro '__unqual_scalar_typeof'
default: (x)))
^
>> mm/vmscan.c:1480:20: error: implicit declaration of function 'page_swap_info' [-Werror,-Wimplicit-function-declaration]
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
^
>> mm/vmscan.c:1480:42: error: member reference type 'int' is not a pointer
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
~~~~~~~~~~~~~~~~~~~~ ^
include/linux/compiler.h:218:3: note: expanded from macro 'data_race'
expr; \
^~~~
>> mm/vmscan.c:1480:9: error: invalid argument type 'void' to unary expression
return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 errors generated.
vim +/page_swap_info +1480 mm/vmscan.c
1467
1468 static bool test_may_enter_fs(struct page *page, gfp_t gfp_mask)
1469 {
1470 if (gfp_mask & __GFP_FS)
1471 return true;
1472 if (!PageSwapCache(page) || !(gfp_mask & __GFP_IO))
1473 return false;
1474 /* We can "enter_fs" for swap-cache with only __GFP_IO
1475 * providing this isn't SWP_FS_OPS.
1476 * ->flags can be updated non-atomicially (scan_swap_map_slots),
1477 * but that will never affect SWP_FS_OPS, so the data_race
1478 * is safe.
1479 */
> 1480 return !data_race(page_swap_info(page)->flags & SWP_FS_OPS);
1481 }
1482
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On Fri, Dec 17, 2021 at 10:48:22AM +1100, NeilBrown wrote: > +static bool test_may_enter_fs(struct page *page, gfp_t gfp_mask) > +{ > + if (gfp_mask & __GFP_FS) > + return true; > + if (!PageSwapCache(page) || !(gfp_mask & __GFP_IO)) > + return false; > + /* We can "enter_fs" for swap-cache with only __GFP_IO > + * providing this isn't SWP_FS_OPS. > + * ->flags can be updated non-atomicially (scan_swap_map_slots), > + * but that will never affect SWP_FS_OPS, so the data_race > + * is safe. > + */ > + return !data_race(page_swap_info(page)->flags & SWP_FS_OPS); Nit: the normal kernel comment style uses an empty /* line to start the comment. > @@ -1514,8 +1529,7 @@ static unsigned int shrink_page_list(struct list_head *page_list, > if (!sc->may_unmap && page_mapped(page)) > goto keep_locked; > > - may_enter_fs = (sc->gfp_mask & __GFP_FS) || > - (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO)); > + may_enter_fs = test_may_enter_fs(page, sc->gfp_mask); > > /* > * The number of dirty pages determines if a node is marked > @@ -1683,7 +1697,8 @@ static unsigned int shrink_page_list(struct list_head *page_list, > goto activate_locked_split; > } > > - may_enter_fs = true; > + may_enter_fs = test_may_enter_fs(page, > + sc->gfp_mask); Now that may_enter_fs is always reset using test_may_enter_fs, do we even need the local variable?
diff --git a/mm/vmscan.c b/mm/vmscan.c index 969bcdb4ca80..5f460d174b1b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1465,6 +1465,21 @@ static unsigned int demote_page_list(struct list_head *demote_pages, return nr_succeeded; } +static bool test_may_enter_fs(struct page *page, gfp_t gfp_mask) +{ + if (gfp_mask & __GFP_FS) + return true; + if (!PageSwapCache(page) || !(gfp_mask & __GFP_IO)) + return false; + /* We can "enter_fs" for swap-cache with only __GFP_IO + * providing this isn't SWP_FS_OPS. + * ->flags can be updated non-atomicially (scan_swap_map_slots), + * but that will never affect SWP_FS_OPS, so the data_race + * is safe. + */ + return !data_race(page_swap_info(page)->flags & SWP_FS_OPS); +} + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -1514,8 +1529,7 @@ static unsigned int shrink_page_list(struct list_head *page_list, if (!sc->may_unmap && page_mapped(page)) goto keep_locked; - may_enter_fs = (sc->gfp_mask & __GFP_FS) || - (PageSwapCache(page) && (sc->gfp_mask & __GFP_IO)); + may_enter_fs = test_may_enter_fs(page, sc->gfp_mask); /* * The number of dirty pages determines if a node is marked @@ -1683,7 +1697,8 @@ static unsigned int shrink_page_list(struct list_head *page_list, goto activate_locked_split; } - may_enter_fs = true; + may_enter_fs = test_may_enter_fs(page, + sc->gfp_mask); /* Adding to swap updated mapping */ mapping = page_mapping(page);
If swap-out is using filesystem operations (SWP_FS_OPS), then it is not safe to enter the FS for reclaim. So only down-grade the requirement for swap pages to __GFP_IO after checking that SWP_FS_OPS are not being used. Signed-off-by: NeilBrown <neilb@suse.de> --- mm/vmscan.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)