Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-14 Thread Minchan Kim 
On Sat, Aug 12, 2017 at 04:46:33PM +0800, kbuild test robot wrote:
> Hi Minchan,
> 
> [auto build test ERROR on mmotm/master]
> [also build test ERROR on next-20170811]
> [cannot apply to linus/master v4.13-rc4]
> [if your patch is applied to the wrong git tree, please drop us a note to 
> help improve the system]
> 
> url:
> https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
> base:   git://git.cmpxchg.org/linux-mmotm.git master
> config: sparc64-allmodconfig (attached as .config)
> compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
> wget 
> https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
> ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=sparc64 
> 
> All errors (new ones prefixed by >>):
> 
>mm/page_io.c: In function '__swap_writepage':
> >> mm/page_io.c:345:11: error: passing argument 1 of 'bio_get' from 
> >> incompatible pointer type [-Werror=incompatible-pointer-types]
>   bio_get();
>   ^
>In file included from include/linux/writeback.h:205:0,
> from include/linux/memcontrol.h:31,
> from include/linux/swap.h:8,
> from mm/page_io.c:17:
>include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is 
> of type 'struct bio **'
> static inline void bio_get(struct bio *bio)
>^~~
>cc1: some warnings being treated as errors
> 
> vim +/bio_get +345 mm/page_io.c
> 
>275
>276int __swap_writepage(struct page *page, struct 
> writeback_control *wbc)
>277{
>278int ret;
>279struct swap_info_struct *sis = page_swap_info(page);
>280struct bio *bio;
>281/* on-stack-bio */
>282struct bio sbio;
>283struct bio_vec sbvec;
>284
>285VM_BUG_ON_PAGE(!PageSwapCache(page), page);
>286if (sis->flags & SWP_FILE) {
>287struct kiocb kiocb;
>288struct file *swap_file = sis->swap_file;
>289struct address_space *mapping = 
> swap_file->f_mapping;
>290struct bio_vec bv = {
>291.bv_page = page,
>292.bv_len  = PAGE_SIZE,
>293.bv_offset = 0
>294};
>295struct iov_iter from;
>296
>297iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
> PAGE_SIZE);
>298init_sync_kiocb(, swap_file);
>299kiocb.ki_pos = page_file_offset(page);
>300
>301set_page_writeback(page);
>302unlock_page(page);
>303ret = mapping->a_ops->direct_IO(, );
>304if (ret == PAGE_SIZE) {
>305count_vm_event(PSWPOUT);
>306ret = 0;
>307} else {
>308/*
>309 * In the case of swap-over-nfs, this 
> can be a
>310 * temporary failure if the system has 
> limited
>311 * memory for allocating transmit 
> buffers.
>312 * Mark the page dirty and avoid
>313 * rotate_reclaimable_page but 
> rate-limit the
>314 * messages but do not flag PageError 
> like
>315 * the normal direct-to-bio case as it 
> could
>316 * be temporary.
>317 */
>318set_page_dirty(page);
>319ClearPageReclaim(page);
>320pr_err_ratelimited("Write error on dio 
> swapfile (%llu)\n",
>321   
> page_file_offset(page));
>322}
>323end_page_writeback(page);
>324return ret;
>325}
>326
>327ret = bdev_write_page(sis->bdev, 
> swap_page_sector(page), page, wbc);
>328if (!ret) {
>329count_swpout_vm_event(page);
>330return 0;
>331}
>332
>333ret = 0;
>334if (!(sis->flags & SWP_SYNC_IO)) {
>335
>336

Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-14 Thread Minchan Kim 
On Sat, Aug 12, 2017 at 04:46:33PM +0800, kbuild test robot wrote:
> Hi Minchan,
> 
> [auto build test ERROR on mmotm/master]
> [also build test ERROR on next-20170811]
> [cannot apply to linus/master v4.13-rc4]
> [if your patch is applied to the wrong git tree, please drop us a note to 
> help improve the system]
> 
> url:
> https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
> base:   git://git.cmpxchg.org/linux-mmotm.git master
> config: sparc64-allmodconfig (attached as .config)
> compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
> wget 
> https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
> ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> make.cross ARCH=sparc64 
> 
> All errors (new ones prefixed by >>):
> 
>mm/page_io.c: In function '__swap_writepage':
> >> mm/page_io.c:345:11: error: passing argument 1 of 'bio_get' from 
> >> incompatible pointer type [-Werror=incompatible-pointer-types]
>   bio_get();
>   ^
>In file included from include/linux/writeback.h:205:0,
> from include/linux/memcontrol.h:31,
> from include/linux/swap.h:8,
> from mm/page_io.c:17:
>include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is 
> of type 'struct bio **'
> static inline void bio_get(struct bio *bio)
>^~~
>cc1: some warnings being treated as errors
> 
> vim +/bio_get +345 mm/page_io.c
> 
>275
>276int __swap_writepage(struct page *page, struct 
> writeback_control *wbc)
>277{
>278int ret;
>279struct swap_info_struct *sis = page_swap_info(page);
>280struct bio *bio;
>281/* on-stack-bio */
>282struct bio sbio;
>283struct bio_vec sbvec;
>284
>285VM_BUG_ON_PAGE(!PageSwapCache(page), page);
>286if (sis->flags & SWP_FILE) {
>287struct kiocb kiocb;
>288struct file *swap_file = sis->swap_file;
>289struct address_space *mapping = 
> swap_file->f_mapping;
>290struct bio_vec bv = {
>291.bv_page = page,
>292.bv_len  = PAGE_SIZE,
>293.bv_offset = 0
>294};
>295struct iov_iter from;
>296
>297iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
> PAGE_SIZE);
>298init_sync_kiocb(, swap_file);
>299kiocb.ki_pos = page_file_offset(page);
>300
>301set_page_writeback(page);
>302unlock_page(page);
>303ret = mapping->a_ops->direct_IO(, );
>304if (ret == PAGE_SIZE) {
>305count_vm_event(PSWPOUT);
>306ret = 0;
>307} else {
>308/*
>309 * In the case of swap-over-nfs, this 
> can be a
>310 * temporary failure if the system has 
> limited
>311 * memory for allocating transmit 
> buffers.
>312 * Mark the page dirty and avoid
>313 * rotate_reclaimable_page but 
> rate-limit the
>314 * messages but do not flag PageError 
> like
>315 * the normal direct-to-bio case as it 
> could
>316 * be temporary.
>317 */
>318set_page_dirty(page);
>319ClearPageReclaim(page);
>320pr_err_ratelimited("Write error on dio 
> swapfile (%llu)\n",
>321   
> page_file_offset(page));
>322}
>323end_page_writeback(page);
>324return ret;
>325}
>326
>327ret = bdev_write_page(sis->bdev, 
> swap_page_sector(page), page, wbc);
>328if (!ret) {
>329count_swpout_vm_event(page);
>330return 0;
>331}
>332
>333ret = 0;
>334if (!(sis->flags & SWP_SYNC_IO)) {
>335
>336

Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-12 Thread kbuild test robot 
Hi Minchan,

[auto build test ERROR on mmotm/master]
[also build test ERROR on next-20170811]
[cannot apply to linus/master v4.13-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: sparc64-allmodconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget 
https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64 

All errors (new ones prefixed by >>):

   mm/page_io.c: In function '__swap_writepage':
>> mm/page_io.c:345:11: error: passing argument 1 of 'bio_get' from 
>> incompatible pointer type [-Werror=incompatible-pointer-types]
  bio_get();
  ^
   In file included from include/linux/writeback.h:205:0,
from include/linux/memcontrol.h:31,
from include/linux/swap.h:8,
from mm/page_io.c:17:
   include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is of 
type 'struct bio **'
static inline void bio_get(struct bio *bio)
   ^~~
   cc1: some warnings being treated as errors

vim +/bio_get +345 mm/page_io.c

   275  
   276  int __swap_writepage(struct page *page, struct writeback_control *wbc)
   277  {
   278  int ret;
   279  struct swap_info_struct *sis = page_swap_info(page);
   280  struct bio *bio;
   281  /* on-stack-bio */
   282  struct bio sbio;
   283  struct bio_vec sbvec;
   284  
   285  VM_BUG_ON_PAGE(!PageSwapCache(page), page);
   286  if (sis->flags & SWP_FILE) {
   287  struct kiocb kiocb;
   288  struct file *swap_file = sis->swap_file;
   289  struct address_space *mapping = swap_file->f_mapping;
   290  struct bio_vec bv = {
   291  .bv_page = page,
   292  .bv_len  = PAGE_SIZE,
   293  .bv_offset = 0
   294  };
   295  struct iov_iter from;
   296  
   297  iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
PAGE_SIZE);
   298  init_sync_kiocb(, swap_file);
   299  kiocb.ki_pos = page_file_offset(page);
   300  
   301  set_page_writeback(page);
   302  unlock_page(page);
   303  ret = mapping->a_ops->direct_IO(, );
   304  if (ret == PAGE_SIZE) {
   305  count_vm_event(PSWPOUT);
   306  ret = 0;
   307  } else {
   308  /*
   309   * In the case of swap-over-nfs, this can be a
   310   * temporary failure if the system has limited
   311   * memory for allocating transmit buffers.
   312   * Mark the page dirty and avoid
   313   * rotate_reclaimable_page but rate-limit the
   314   * messages but do not flag PageError like
   315   * the normal direct-to-bio case as it could
   316   * be temporary.
   317   */
   318  set_page_dirty(page);
   319  ClearPageReclaim(page);
   320  pr_err_ratelimited("Write error on dio swapfile 
(%llu)\n",
   321 page_file_offset(page));
   322  }
   323  end_page_writeback(page);
   324  return ret;
   325  }
   326  
   327  ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, 
wbc);
   328  if (!ret) {
   329  count_swpout_vm_event(page);
   330  return 0;
   331  }
   332  
   333  ret = 0;
   334  if (!(sis->flags & SWP_SYNC_IO)) {
   335  
   336  bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
   337  if (bio == NULL) {
   338  set_page_dirty(page);
   339  unlock_page(page);
   340  ret = -ENOMEM;
   341  goto out;
   342  }
   343  } else {
   344  bio = 
 > 345  bio_get();
   346  
   347  bio_init(, , 1);
   348  sbio.bi_bdev = sis->bdev;
   349  sbio.bi_iter.bi_sector = swap_page_sector(page);
   350  sbio.bi_end_io = end_swap_bio_write;
   351

Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-12 Thread kbuild test robot 
Hi Minchan,

[auto build test ERROR on mmotm/master]
[also build test ERROR on next-20170811]
[cannot apply to linus/master v4.13-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: sparc64-allmodconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget 
https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64 

All errors (new ones prefixed by >>):

   mm/page_io.c: In function '__swap_writepage':
>> mm/page_io.c:345:11: error: passing argument 1 of 'bio_get' from 
>> incompatible pointer type [-Werror=incompatible-pointer-types]
  bio_get();
  ^
   In file included from include/linux/writeback.h:205:0,
from include/linux/memcontrol.h:31,
from include/linux/swap.h:8,
from mm/page_io.c:17:
   include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is of 
type 'struct bio **'
static inline void bio_get(struct bio *bio)
   ^~~
   cc1: some warnings being treated as errors

vim +/bio_get +345 mm/page_io.c

   275  
   276  int __swap_writepage(struct page *page, struct writeback_control *wbc)
   277  {
   278  int ret;
   279  struct swap_info_struct *sis = page_swap_info(page);
   280  struct bio *bio;
   281  /* on-stack-bio */
   282  struct bio sbio;
   283  struct bio_vec sbvec;
   284  
   285  VM_BUG_ON_PAGE(!PageSwapCache(page), page);
   286  if (sis->flags & SWP_FILE) {
   287  struct kiocb kiocb;
   288  struct file *swap_file = sis->swap_file;
   289  struct address_space *mapping = swap_file->f_mapping;
   290  struct bio_vec bv = {
   291  .bv_page = page,
   292  .bv_len  = PAGE_SIZE,
   293  .bv_offset = 0
   294  };
   295  struct iov_iter from;
   296  
   297  iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
PAGE_SIZE);
   298  init_sync_kiocb(, swap_file);
   299  kiocb.ki_pos = page_file_offset(page);
   300  
   301  set_page_writeback(page);
   302  unlock_page(page);
   303  ret = mapping->a_ops->direct_IO(, );
   304  if (ret == PAGE_SIZE) {
   305  count_vm_event(PSWPOUT);
   306  ret = 0;
   307  } else {
   308  /*
   309   * In the case of swap-over-nfs, this can be a
   310   * temporary failure if the system has limited
   311   * memory for allocating transmit buffers.
   312   * Mark the page dirty and avoid
   313   * rotate_reclaimable_page but rate-limit the
   314   * messages but do not flag PageError like
   315   * the normal direct-to-bio case as it could
   316   * be temporary.
   317   */
   318  set_page_dirty(page);
   319  ClearPageReclaim(page);
   320  pr_err_ratelimited("Write error on dio swapfile 
(%llu)\n",
   321 page_file_offset(page));
   322  }
   323  end_page_writeback(page);
   324  return ret;
   325  }
   326  
   327  ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, 
wbc);
   328  if (!ret) {
   329  count_swpout_vm_event(page);
   330  return 0;
   331  }
   332  
   333  ret = 0;
   334  if (!(sis->flags & SWP_SYNC_IO)) {
   335  
   336  bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
   337  if (bio == NULL) {
   338  set_page_dirty(page);
   339  unlock_page(page);
   340  ret = -ENOMEM;
   341  goto out;
   342  }
   343  } else {
   344  bio = 
 > 345  bio_get();
   346  
   347  bio_init(, , 1);
   348  sbio.bi_bdev = sis->bdev;
   349  sbio.bi_iter.bi_sector = swap_page_sector(page);
   350  sbio.bi_end_io = end_swap_bio_write;
   351

Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-12 Thread kbuild test robot 
Hi Minchan,

[auto build test WARNING on mmotm/master]
[also build test WARNING on next-20170811]
[cannot apply to linus/master v4.13-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
wget 
https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa 

All warnings (new ones prefixed by >>):

   mm/page_io.c: In function '__swap_writepage':
>> mm/page_io.c:345:3: warning: passing argument 1 of 'bio_get' from 
>> incompatible pointer type
  bio_get();
  ^
   In file included from include/linux/writeback.h:205:0,
from include/linux/memcontrol.h:31,
from include/linux/swap.h:8,
from mm/page_io.c:17:
   include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is of 
type 'struct bio **'
static inline void bio_get(struct bio *bio)
   ^

vim +/bio_get +345 mm/page_io.c

   275  
   276  int __swap_writepage(struct page *page, struct writeback_control *wbc)
   277  {
   278  int ret;
   279  struct swap_info_struct *sis = page_swap_info(page);
   280  struct bio *bio;
   281  /* on-stack-bio */
   282  struct bio sbio;
   283  struct bio_vec sbvec;
   284  
   285  VM_BUG_ON_PAGE(!PageSwapCache(page), page);
   286  if (sis->flags & SWP_FILE) {
   287  struct kiocb kiocb;
   288  struct file *swap_file = sis->swap_file;
   289  struct address_space *mapping = swap_file->f_mapping;
   290  struct bio_vec bv = {
   291  .bv_page = page,
   292  .bv_len  = PAGE_SIZE,
   293  .bv_offset = 0
   294  };
   295  struct iov_iter from;
   296  
   297  iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
PAGE_SIZE);
   298  init_sync_kiocb(, swap_file);
   299  kiocb.ki_pos = page_file_offset(page);
   300  
   301  set_page_writeback(page);
   302  unlock_page(page);
   303  ret = mapping->a_ops->direct_IO(, );
   304  if (ret == PAGE_SIZE) {
   305  count_vm_event(PSWPOUT);
   306  ret = 0;
   307  } else {
   308  /*
   309   * In the case of swap-over-nfs, this can be a
   310   * temporary failure if the system has limited
   311   * memory for allocating transmit buffers.
   312   * Mark the page dirty and avoid
   313   * rotate_reclaimable_page but rate-limit the
   314   * messages but do not flag PageError like
   315   * the normal direct-to-bio case as it could
   316   * be temporary.
   317   */
   318  set_page_dirty(page);
   319  ClearPageReclaim(page);
   320  pr_err_ratelimited("Write error on dio swapfile 
(%llu)\n",
   321 page_file_offset(page));
   322  }
   323  end_page_writeback(page);
   324  return ret;
   325  }
   326  
   327  ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, 
wbc);
   328  if (!ret) {
   329  count_swpout_vm_event(page);
   330  return 0;
   331  }
   332  
   333  ret = 0;
   334  if (!(sis->flags & SWP_SYNC_IO)) {
   335  
   336  bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
   337  if (bio == NULL) {
   338  set_page_dirty(page);
   339  unlock_page(page);
   340  ret = -ENOMEM;
   341  goto out;
   342  }
   343  } else {
   344  bio = 
 > 345  bio_get();
   346  
   347  bio_init(, , 1);
   348  sbio.bi_bdev = sis->bdev;
   349  sbio.bi_iter.bi_sector = swap_page_sector(page);
   350  sbio.bi_end_io = end_swap_bio_write;
   351  bio_add_page(, page, PAGE_SIZE, 0);
   352  }
   353  
   354  bio_set_op_attrs(bio, REQ_OP_WRITE,

Re: [PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-12 Thread kbuild test robot 
Hi Minchan,

[auto build test WARNING on mmotm/master]
[also build test WARNING on next-20170811]
[cannot apply to linus/master v4.13-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Minchan-Kim/Replace-rw_page-with-on-stack-bio/20170812-152541
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
wget 
https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O 
~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa 

All warnings (new ones prefixed by >>):

   mm/page_io.c: In function '__swap_writepage':
>> mm/page_io.c:345:3: warning: passing argument 1 of 'bio_get' from 
>> incompatible pointer type
  bio_get();
  ^
   In file included from include/linux/writeback.h:205:0,
from include/linux/memcontrol.h:31,
from include/linux/swap.h:8,
from mm/page_io.c:17:
   include/linux/bio.h:252:20: note: expected 'struct bio *' but argument is of 
type 'struct bio **'
static inline void bio_get(struct bio *bio)
   ^

vim +/bio_get +345 mm/page_io.c

   275  
   276  int __swap_writepage(struct page *page, struct writeback_control *wbc)
   277  {
   278  int ret;
   279  struct swap_info_struct *sis = page_swap_info(page);
   280  struct bio *bio;
   281  /* on-stack-bio */
   282  struct bio sbio;
   283  struct bio_vec sbvec;
   284  
   285  VM_BUG_ON_PAGE(!PageSwapCache(page), page);
   286  if (sis->flags & SWP_FILE) {
   287  struct kiocb kiocb;
   288  struct file *swap_file = sis->swap_file;
   289  struct address_space *mapping = swap_file->f_mapping;
   290  struct bio_vec bv = {
   291  .bv_page = page,
   292  .bv_len  = PAGE_SIZE,
   293  .bv_offset = 0
   294  };
   295  struct iov_iter from;
   296  
   297  iov_iter_bvec(, ITER_BVEC | WRITE, , 1, 
PAGE_SIZE);
   298  init_sync_kiocb(, swap_file);
   299  kiocb.ki_pos = page_file_offset(page);
   300  
   301  set_page_writeback(page);
   302  unlock_page(page);
   303  ret = mapping->a_ops->direct_IO(, );
   304  if (ret == PAGE_SIZE) {
   305  count_vm_event(PSWPOUT);
   306  ret = 0;
   307  } else {
   308  /*
   309   * In the case of swap-over-nfs, this can be a
   310   * temporary failure if the system has limited
   311   * memory for allocating transmit buffers.
   312   * Mark the page dirty and avoid
   313   * rotate_reclaimable_page but rate-limit the
   314   * messages but do not flag PageError like
   315   * the normal direct-to-bio case as it could
   316   * be temporary.
   317   */
   318  set_page_dirty(page);
   319  ClearPageReclaim(page);
   320  pr_err_ratelimited("Write error on dio swapfile 
(%llu)\n",
   321 page_file_offset(page));
   322  }
   323  end_page_writeback(page);
   324  return ret;
   325  }
   326  
   327  ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, 
wbc);
   328  if (!ret) {
   329  count_swpout_vm_event(page);
   330  return 0;
   331  }
   332  
   333  ret = 0;
   334  if (!(sis->flags & SWP_SYNC_IO)) {
   335  
   336  bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
   337  if (bio == NULL) {
   338  set_page_dirty(page);
   339  unlock_page(page);
   340  ret = -ENOMEM;
   341  goto out;
   342  }
   343  } else {
   344  bio = 
 > 345  bio_get();
   346  
   347  bio_init(, , 1);
   348  sbio.bi_bdev = sis->bdev;
   349  sbio.bi_iter.bi_sector = swap_page_sector(page);
   350  sbio.bi_end_io = end_swap_bio_write;
   351  bio_add_page(, page, PAGE_SIZE, 0);
   352  }
   353  
   354  bio_set_op_attrs(bio, REQ_OP_WRITE,

[PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-10 Thread Minchan Kim 
There is no need to use dynamic bio allocation for BDI_CAP_SYNCHRONOUS
devices. They can live with on-stack-bio without concern about
waiting bio allocation from mempool under heavy memory pressure.

It would be much better for swap devices because the bio mempool
for swap IO have been used with fs. It means super-fast swap
IO like zram don't need to depends on slow eMMC read/write
completion.

Signed-off-by: Minchan Kim 
---
 include/linux/swap.h |  3 ++-
 mm/page_io.c | 70 +---
 mm/swapfile.c|  3 +++
 3 files changed, 55 insertions(+), 21 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index ae3da979a7b7..6ed9b6423f7d 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -152,8 +152,9 @@ enum {
SWP_AREA_DISCARD = (1 << 8),/* single-time swap area discards */
SWP_PAGE_DISCARD = (1 << 9),/* freed swap page-cluster discards */
SWP_STABLE_WRITES = (1 << 10),  /* no overwrite PG_writeback pages */
+   SWP_SYNC_IO = (1<<11),  /* synchronous IO is efficient */
/* add others here before... */
-   SWP_SCANNING= (1 << 11),/* refcount in scan_swap_map */
+   SWP_SCANNING= (1 << 12),/* refcount in scan_swap_map */
 };
 
 #define SWAP_CLUSTER_MAX 32UL
diff --git a/mm/page_io.c b/mm/page_io.c
index 3502a97f7c48..64330c751548 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -119,8 +119,8 @@ static void swap_slot_free_notify(struct page *page)
 
 static void end_swap_bio_read(struct bio *bio)
 {
-   struct page *page = bio->bi_io_vec[0].bv_page;
struct task_struct *waiter = bio->bi_private;
+   struct page *page = bio->bi_io_vec[0].bv_page;
 
if (bio->bi_status) {
SetPageError(page);
@@ -275,9 +275,12 @@ static inline void count_swpout_vm_event(struct page *page)
 
 int __swap_writepage(struct page *page, struct writeback_control *wbc)
 {
-   struct bio *bio;
int ret;
struct swap_info_struct *sis = page_swap_info(page);
+   struct bio *bio;
+   /* on-stack-bio */
+   struct bio sbio;
+   struct bio_vec sbvec;
 
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
if (sis->flags & SWP_FILE) {
@@ -328,29 +331,45 @@ int __swap_writepage(struct page *page, struct 
writeback_control *wbc)
}
 
ret = 0;
-   bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
-   if (bio == NULL) {
-   set_page_dirty(page);
-   unlock_page(page);
-   ret = -ENOMEM;
-   goto out;
+   if (!(sis->flags & SWP_SYNC_IO)) {
+
+   bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
+   if (bio == NULL) {
+   set_page_dirty(page);
+   unlock_page(page);
+   ret = -ENOMEM;
+   goto out;
+   }
+   } else {
+   bio = 
+   bio_get();
+
+   bio_init(, , 1);
+   sbio.bi_bdev = sis->bdev;
+   sbio.bi_iter.bi_sector = swap_page_sector(page);
+   sbio.bi_end_io = end_swap_bio_write;
+   bio_add_page(, page, PAGE_SIZE, 0);
}
-   bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc);
-   count_swpout_vm_event(page);
+
+   bio_set_op_attrs(bio, REQ_OP_WRITE, wbc_to_write_flags(wbc));
set_page_writeback(page);
unlock_page(page);
submit_bio(bio);
+   count_swpout_vm_event(page);
 out:
return ret;
 }
 
 int swap_readpage(struct page *page, bool do_poll)
 {
-   struct bio *bio;
int ret = 0;
struct swap_info_struct *sis = page_swap_info(page);
blk_qc_t qc;
struct block_device *bdev;
+   struct bio *bio;
+   /* on-stack-bio */
+   struct bio sbio;
+   struct bio_vec sbvec;
 
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
@@ -383,21 +402,33 @@ int swap_readpage(struct page *page, bool do_poll)
}
 
ret = 0;
-   bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
-   if (bio == NULL) {
-   unlock_page(page);
-   ret = -ENOMEM;
-   goto out;
+   count_vm_event(PSWPIN);
+   if (!(sis->flags & SWP_SYNC_IO)) {
+   bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
+   if (bio == NULL) {
+   unlock_page(page);
+   ret = -ENOMEM;
+   goto out;
+   }
+   } else {
+   bio = 
+   bio_get(bio);
+
+   bio_init(, , 1);
+   sbio.bi_bdev = sis->bdev;
+   sbio.bi_iter.bi_sector = swap_page_sector(page);
+   bio->bi_end_io = end_swap_bio_read;
+   bio_add_page(, page, PAGE_SIZE, 0);

[PATCH v2 5/7] mm:swap: use on-stack-bio for BDI_CAP_SYNCHRONOUS device

2017-08-10 Thread Minchan Kim 
There is no need to use dynamic bio allocation for BDI_CAP_SYNCHRONOUS
devices. They can live with on-stack-bio without concern about
waiting bio allocation from mempool under heavy memory pressure.

It would be much better for swap devices because the bio mempool
for swap IO have been used with fs. It means super-fast swap
IO like zram don't need to depends on slow eMMC read/write
completion.

Signed-off-by: Minchan Kim 
---
 include/linux/swap.h |  3 ++-
 mm/page_io.c | 70 +---
 mm/swapfile.c|  3 +++
 3 files changed, 55 insertions(+), 21 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index ae3da979a7b7..6ed9b6423f7d 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -152,8 +152,9 @@ enum {
SWP_AREA_DISCARD = (1 << 8),/* single-time swap area discards */
SWP_PAGE_DISCARD = (1 << 9),/* freed swap page-cluster discards */
SWP_STABLE_WRITES = (1 << 10),  /* no overwrite PG_writeback pages */
+   SWP_SYNC_IO = (1<<11),  /* synchronous IO is efficient */
/* add others here before... */
-   SWP_SCANNING= (1 << 11),/* refcount in scan_swap_map */
+   SWP_SCANNING= (1 << 12),/* refcount in scan_swap_map */
 };
 
 #define SWAP_CLUSTER_MAX 32UL
diff --git a/mm/page_io.c b/mm/page_io.c
index 3502a97f7c48..64330c751548 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -119,8 +119,8 @@ static void swap_slot_free_notify(struct page *page)
 
 static void end_swap_bio_read(struct bio *bio)
 {
-   struct page *page = bio->bi_io_vec[0].bv_page;
struct task_struct *waiter = bio->bi_private;
+   struct page *page = bio->bi_io_vec[0].bv_page;
 
if (bio->bi_status) {
SetPageError(page);
@@ -275,9 +275,12 @@ static inline void count_swpout_vm_event(struct page *page)
 
 int __swap_writepage(struct page *page, struct writeback_control *wbc)
 {
-   struct bio *bio;
int ret;
struct swap_info_struct *sis = page_swap_info(page);
+   struct bio *bio;
+   /* on-stack-bio */
+   struct bio sbio;
+   struct bio_vec sbvec;
 
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
if (sis->flags & SWP_FILE) {
@@ -328,29 +331,45 @@ int __swap_writepage(struct page *page, struct 
writeback_control *wbc)
}
 
ret = 0;
-   bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
-   if (bio == NULL) {
-   set_page_dirty(page);
-   unlock_page(page);
-   ret = -ENOMEM;
-   goto out;
+   if (!(sis->flags & SWP_SYNC_IO)) {
+
+   bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
+   if (bio == NULL) {
+   set_page_dirty(page);
+   unlock_page(page);
+   ret = -ENOMEM;
+   goto out;
+   }
+   } else {
+   bio = 
+   bio_get();
+
+   bio_init(, , 1);
+   sbio.bi_bdev = sis->bdev;
+   sbio.bi_iter.bi_sector = swap_page_sector(page);
+   sbio.bi_end_io = end_swap_bio_write;
+   bio_add_page(, page, PAGE_SIZE, 0);
}
-   bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc);
-   count_swpout_vm_event(page);
+
+   bio_set_op_attrs(bio, REQ_OP_WRITE, wbc_to_write_flags(wbc));
set_page_writeback(page);
unlock_page(page);
submit_bio(bio);
+   count_swpout_vm_event(page);
 out:
return ret;
 }
 
 int swap_readpage(struct page *page, bool do_poll)
 {
-   struct bio *bio;
int ret = 0;
struct swap_info_struct *sis = page_swap_info(page);
blk_qc_t qc;
struct block_device *bdev;
+   struct bio *bio;
+   /* on-stack-bio */
+   struct bio sbio;
+   struct bio_vec sbvec;
 
VM_BUG_ON_PAGE(!PageSwapCache(page), page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
@@ -383,21 +402,33 @@ int swap_readpage(struct page *page, bool do_poll)
}
 
ret = 0;
-   bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
-   if (bio == NULL) {
-   unlock_page(page);
-   ret = -ENOMEM;
-   goto out;
+   count_vm_event(PSWPIN);
+   if (!(sis->flags & SWP_SYNC_IO)) {
+   bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
+   if (bio == NULL) {
+   unlock_page(page);
+   ret = -ENOMEM;
+   goto out;
+   }
+   } else {
+   bio = 
+   bio_get(bio);
+
+   bio_init(, , 1);
+   sbio.bi_bdev = sis->bdev;
+   sbio.bi_iter.bi_sector = swap_page_sector(page);
+   bio->bi_end_io = end_swap_bio_read;
+   bio_add_page(, page, PAGE_SIZE, 0);
}
bdev =