Since commit 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
and commit ba925fa35057 ("s390/gmap: improve THP splitting") FOLL_SPLIT
has not been used anymore. Remove the dead code.
Signed-off-by: Yang Shi <[email protected]>
---
include/linux/mm.h | 1 -
mm/gup.c | 28 ++--------------------------
2 files changed, 2 insertions(+), 27 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8ba434287387..3568836841f9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2780,7 +2780,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
#define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
* and return without waiting upon it */
#define FOLL_POPULATE 0x40 /* fault in page */
-#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */
#define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
#define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
#define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
diff --git a/mm/gup.c b/mm/gup.c
index e40579624f10..f3d45a8f18ae 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -435,18 +435,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
}
}
- if (flags & FOLL_SPLIT && PageTransCompound(page)) {
- get_page(page);
- pte_unmap_unlock(ptep, ptl);
- lock_page(page);
- ret = split_huge_page(page);
- unlock_page(page);
- put_page(page);
- if (ret)
- return ERR_PTR(ret);
- goto retry;
- }
-
/* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */
if (unlikely(!try_grab_page(page, flags))) {
page = ERR_PTR(-ENOMEM);
@@ -591,7 +579,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
spin_unlock(ptl);
return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap);
}
- if (flags & (FOLL_SPLIT | FOLL_SPLIT_PMD)) {
+ if (flags & FOLL_SPLIT_PMD) {
int ret;
page = pmd_page(*pmd);
if (is_huge_zero_page(page)) {
@@ -600,19 +588,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
split_huge_pmd(vma, pmd, address);
if (pmd_trans_unstable(pmd))
ret = -EBUSY;
- } else if (flags & FOLL_SPLIT) {
- if (unlikely(!try_get_page(page))) {
- spin_unlock(ptl);
- return ERR_PTR(-ENOMEM);
- }
- spin_unlock(ptl);
- lock_page(page);
- ret = split_huge_page(page);
- unlock_page(page);
- put_page(page);
- if (pmd_none(*pmd))
- return no_page_table(vma, flags);
- } else { /* flags & FOLL_SPLIT_PMD */
+ } else {
spin_unlock(ptl);
split_huge_pmd(vma, pmd, address);
ret = pte_alloc(mm, pmd) ? -ENOMEM : 0;
--
2.26.2
Hi Yang,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on hnaz-linux-mm/master]
url: https://github.com/0day-ci/linux/commits/Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
base: https://github.com/hnaz/linux-mm master
config: s390-randconfig-r032-20210330 (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
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/0day-ci/linux/commit/c8563a636718f98af86a3965d94e25b8f2cf2354
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
git checkout c8563a636718f98af86a3965d94e25b8f2cf2354
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
arch/s390/mm/gmap.c: In function 'thp_split_mm':
>> arch/s390/mm/gmap.c:2498:27: error: 'FOLL_SPLIT' undeclared (first use in this function); did you mean 'FOLL_PIN'?
2498 | follow_page(vma, addr, FOLL_SPLIT);
| ^~~~~~~~~~
| FOLL_PIN
arch/s390/mm/gmap.c:2498:27: note: each undeclared identifier is reported only once for each function it appears in
vim +2498 arch/s390/mm/gmap.c
0959e168678d2d Janosch Frank 2018-07-17 2487
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2488 static inline void thp_split_mm(struct mm_struct *mm)
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2489 {
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2490 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2491 struct vm_area_struct *vma;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2492 unsigned long addr;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2493
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2494 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2495 for (addr = vma->vm_start;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2496 addr < vma->vm_end;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2497 addr += PAGE_SIZE)
1e133ab296f3ff Martin Schwidefsky 2016-03-08 @2498 follow_page(vma, addr, FOLL_SPLIT);
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2499 vma->vm_flags &= ~VM_HUGEPAGE;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2500 vma->vm_flags |= VM_NOHUGEPAGE;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2501 }
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2502 mm->def_flags |= VM_NOHUGEPAGE;
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2503 #endif
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2504 }
1e133ab296f3ff Martin Schwidefsky 2016-03-08 2505
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
On 3/29/21 12:38 PM, Yang Shi wrote:
> Since commit 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
> and commit ba925fa35057 ("s390/gmap: improve THP splitting") FOLL_SPLIT
> has not been used anymore. Remove the dead code.
>
> Signed-off-by: Yang Shi <[email protected]>
> ---
> include/linux/mm.h | 1 -
> mm/gup.c | 28 ++--------------------------
> 2 files changed, 2 insertions(+), 27 deletions(-)
>
Looks nice.
As long as I'm running git grep here, there is one more search hit that should also
be fixed up, as part of a "remove FOLL_SPLIT" patch:
git grep -nw FOLL_SPLIT
Documentation/vm/transhuge.rst:57:follow_page, the FOLL_SPLIT bit can be specified as a parameter to
Reviewed-by: John Hubbard <[email protected]>
thanks,
--
John Hubbard
NVIDIA
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 8ba434287387..3568836841f9 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2780,7 +2780,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
> #define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
> * and return without waiting upon it */
> #define FOLL_POPULATE 0x40 /* fault in page */
> -#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */
> #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
> #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
> #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
> diff --git a/mm/gup.c b/mm/gup.c
> index e40579624f10..f3d45a8f18ae 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -435,18 +435,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
> }
> }
>
> - if (flags & FOLL_SPLIT && PageTransCompound(page)) {
> - get_page(page);
> - pte_unmap_unlock(ptep, ptl);
> - lock_page(page);
> - ret = split_huge_page(page);
> - unlock_page(page);
> - put_page(page);
> - if (ret)
> - return ERR_PTR(ret);
> - goto retry;
> - }
> -
> /* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */
> if (unlikely(!try_grab_page(page, flags))) {
> page = ERR_PTR(-ENOMEM);
> @@ -591,7 +579,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
> spin_unlock(ptl);
> return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap);
> }
> - if (flags & (FOLL_SPLIT | FOLL_SPLIT_PMD)) {
> + if (flags & FOLL_SPLIT_PMD) {
> int ret;
> page = pmd_page(*pmd);
> if (is_huge_zero_page(page)) {
> @@ -600,19 +588,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
> split_huge_pmd(vma, pmd, address);
> if (pmd_trans_unstable(pmd))
> ret = -EBUSY;
> - } else if (flags & FOLL_SPLIT) {
> - if (unlikely(!try_get_page(page))) {
> - spin_unlock(ptl);
> - return ERR_PTR(-ENOMEM);
> - }
> - spin_unlock(ptl);
> - lock_page(page);
> - ret = split_huge_page(page);
> - unlock_page(page);
> - put_page(page);
> - if (pmd_none(*pmd))
> - return no_page_table(vma, flags);
> - } else { /* flags & FOLL_SPLIT_PMD */
> + } else {
> spin_unlock(ptl);
> split_huge_pmd(vma, pmd, address);
> ret = pte_alloc(mm, pmd) ? -ENOMEM : 0;
>
On 3/29/21 11:24 PM, kernel test robot wrote:
> Hi Yang,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on hnaz-linux-mm/master]
>
> url: https://github.com/0day-ci/linux/commits/Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
> base: https://github.com/hnaz/linux-mm master
> config: s390-randconfig-r032-20210330 (attached as .config)
> compiler: s390-linux-gcc (GCC) 9.3.0
> 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/0day-ci/linux/commit/c8563a636718f98af86a3965d94e25b8f2cf2354
> git remote add linux-review https://github.com/0day-ci/linux
> git fetch --no-tags linux-review Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
> git checkout c8563a636718f98af86a3965d94e25b8f2cf2354
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
>
> All errors (new ones prefixed by >>):
>
> arch/s390/mm/gmap.c: In function 'thp_split_mm':
>>> arch/s390/mm/gmap.c:2498:27: error: 'FOLL_SPLIT' undeclared (first use in this function); did you mean 'FOLL_PIN'?
> 2498 | follow_page(vma, addr, FOLL_SPLIT);
> | ^~~~~~~~~~
> | FOLL_PIN
> arch/s390/mm/gmap.c:2498:27: note: each undeclared identifier is reported only once for each function it appears in
>
>
> vim +2498 arch/s390/mm/gmap.c
There appears to be an imperfection in this 0day testing system, because (just as the patch
says), commit ba925fa35057a062ac98c3e8138b013ce4ce351c ("s390/gmap: improve THP splitting"),
July 29, 2020, removes the above use of FOLL_SPLIT.
And "git grep", just to be sure, shows it is not there in today's linux.git. So I guess the
https://github.com/0day-ci/linux repo needs a better way to stay in sync?
thanks,
--
John Hubbard
NVIDIA
On Tue, Mar 30, 2021 at 12:08 AM John Hubbard <[email protected]> wrote:
>
> On 3/29/21 12:38 PM, Yang Shi wrote:
> > Since commit 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
> > and commit ba925fa35057 ("s390/gmap: improve THP splitting") FOLL_SPLIT
> > has not been used anymore. Remove the dead code.
> >
> > Signed-off-by: Yang Shi <[email protected]>
> > ---
> > include/linux/mm.h | 1 -
> > mm/gup.c | 28 ++--------------------------
> > 2 files changed, 2 insertions(+), 27 deletions(-)
> >
>
> Looks nice.
>
> As long as I'm running git grep here, there is one more search hit that should also
> be fixed up, as part of a "remove FOLL_SPLIT" patch:
>
> git grep -nw FOLL_SPLIT
> Documentation/vm/transhuge.rst:57:follow_page, the FOLL_SPLIT bit can be specified as a parameter to
>
> Reviewed-by: John Hubbard <[email protected]>
Thanks. Removed the reference to FOLL_SPLIT in documentation for v2.
>
> thanks,
> --
> John Hubbard
> NVIDIA
>
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 8ba434287387..3568836841f9 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2780,7 +2780,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
> > #define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
> > * and return without waiting upon it */
> > #define FOLL_POPULATE 0x40 /* fault in page */
> > -#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */
> > #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
> > #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
> > #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
> > diff --git a/mm/gup.c b/mm/gup.c
> > index e40579624f10..f3d45a8f18ae 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -435,18 +435,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
> > }
> > }
> >
> > - if (flags & FOLL_SPLIT && PageTransCompound(page)) {
> > - get_page(page);
> > - pte_unmap_unlock(ptep, ptl);
> > - lock_page(page);
> > - ret = split_huge_page(page);
> > - unlock_page(page);
> > - put_page(page);
> > - if (ret)
> > - return ERR_PTR(ret);
> > - goto retry;
> > - }
> > -
> > /* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */
> > if (unlikely(!try_grab_page(page, flags))) {
> > page = ERR_PTR(-ENOMEM);
> > @@ -591,7 +579,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
> > spin_unlock(ptl);
> > return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap);
> > }
> > - if (flags & (FOLL_SPLIT | FOLL_SPLIT_PMD)) {
> > + if (flags & FOLL_SPLIT_PMD) {
> > int ret;
> > page = pmd_page(*pmd);
> > if (is_huge_zero_page(page)) {
> > @@ -600,19 +588,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
> > split_huge_pmd(vma, pmd, address);
> > if (pmd_trans_unstable(pmd))
> > ret = -EBUSY;
> > - } else if (flags & FOLL_SPLIT) {
> > - if (unlikely(!try_get_page(page))) {
> > - spin_unlock(ptl);
> > - return ERR_PTR(-ENOMEM);
> > - }
> > - spin_unlock(ptl);
> > - lock_page(page);
> > - ret = split_huge_page(page);
> > - unlock_page(page);
> > - put_page(page);
> > - if (pmd_none(*pmd))
> > - return no_page_table(vma, flags);
> > - } else { /* flags & FOLL_SPLIT_PMD */
> > + } else {
> > spin_unlock(ptl);
> > split_huge_pmd(vma, pmd, address);
> > ret = pte_alloc(mm, pmd) ? -ENOMEM : 0;
> >
>
Hi John,
On 3/30/21 3:08 PM, John Hubbard wrote:
> On 3/29/21 11:24 PM, kernel test robot wrote:
>> Hi Yang,
>>
>> Thank you for the patch! Yet something to improve:
>>
>> [auto build test ERROR on hnaz-linux-mm/master]
>>
>> url:
>> https://github.com/0day-ci/linux/commits/Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
>> base: https://github.com/hnaz/linux-mm master
>> config: s390-randconfig-r032-20210330 (attached as .config)
>> compiler: s390-linux-gcc (GCC) 9.3.0
>> 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/0day-ci/linux/commit/c8563a636718f98af86a3965d94e25b8f2cf2354
>> git remote add linux-review https://github.com/0day-ci/linux
>> git fetch --no-tags linux-review
>> Yang-Shi/mm-gup-remove-FOLL_SPLIT/20210330-034042
>> git checkout c8563a636718f98af86a3965d94e25b8f2cf2354
>> # save the attached .config to linux build tree
>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0
>> make.cross ARCH=s390
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <[email protected]>
>>
>> All errors (new ones prefixed by >>):
>>
>> arch/s390/mm/gmap.c: In function 'thp_split_mm':
>>>> arch/s390/mm/gmap.c:2498:27: error: 'FOLL_SPLIT' undeclared (first
>>>> use in this function); did you mean 'FOLL_PIN'?
>> 2498 | follow_page(vma, addr, FOLL_SPLIT);
>> | ^~~~~~~~~~
>> | FOLL_PIN
>> arch/s390/mm/gmap.c:2498:27: note: each undeclared identifier is
>> reported only once for each function it appears in
>>
>>
>> vim +2498 arch/s390/mm/gmap.c
>
> There appears to be an imperfection in this 0day testing system,
> because (just as the patch
> says), commit ba925fa35057a062ac98c3e8138b013ce4ce351c ("s390/gmap:
> improve THP splitting"),
> July 29, 2020, removes the above use of FOLL_SPLIT.
>
> And "git grep", just to be sure, shows it is not there in today's
> linux.git. So I guess the
> https://github.com/0day-ci/linux repo needs a better way to stay in sync?
Sorry for the delay, indeed, it's a issue from 0day-CI, we'll update
linux-mm in the system.
Best Regards,
Rong Chen