[aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3413 bytes --]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git mapcount_deshare
head:   3e2f198cce0c1792ad71d6d81974b091019b6483
commit: 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 [20/27] mm: gup: pack has_pinned in MMF_HAS_PINNED
config: arm-randconfig-r014-20210511 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
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://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=8dec302e87453234fc7ac1cf4d09e4d577a06cf3
        git remote add aa https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
        git fetch --no-tags aa mapcount_deshare
        git checkout 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 

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/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag' [-Werror,-Wimplicit-function-declaration]
                   mm_set_has_pinned_flag(&current->mm->flags);
                   ^
   1 error generated.


vim +/mm_set_has_pinned_flag +2756 mm/gup.c

  2740	
  2741	static int internal_get_user_pages_fast(unsigned long start,
  2742						unsigned long nr_pages,
  2743						unsigned int gup_flags,
  2744						struct page **pages)
  2745	{
  2746		unsigned long len, end;
  2747		unsigned long nr_pinned;
  2748		int ret;
  2749	
  2750		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM |
  2751					       FOLL_FORCE | FOLL_PIN | FOLL_GET |
  2752					       FOLL_FAST_ONLY)))
  2753			return -EINVAL;
  2754	
  2755		if (gup_flags & FOLL_PIN)
> 2756			mm_set_has_pinned_flag(&current->mm->flags);
  2757	
  2758		if (!(gup_flags & FOLL_FAST_ONLY))
  2759			might_lock_read(&current->mm->mmap_lock);
  2760	
  2761		start = untagged_addr(start) & PAGE_MASK;
  2762		len = nr_pages << PAGE_SHIFT;
  2763		if (check_add_overflow(start, len, &end))
  2764			return 0;
  2765		if (unlikely(!access_ok((void __user *)start, len)))
  2766			return -EFAULT;
  2767	
  2768		nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
  2769		if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
  2770			return nr_pinned;
  2771	
  2772		/* Slow path: try to get the remaining pages with get_user_pages */
  2773		start += nr_pinned << PAGE_SHIFT;
  2774		pages += nr_pinned;
  2775		ret = __gup_longterm_unlocked(start, nr_pages - nr_pinned, gup_flags,
  2776					      pages);
  2777		if (ret < 0) {
  2778			/*
  2779			 * The caller has to unpin the pages we already pinned so
  2780			 * returning -errno is not an option
  2781			 */
  2782			if (nr_pinned)
  2783				return nr_pinned;
  2784			return ret;
  2785		}
  2786		return ret + nr_pinned;
  2787	}
  2788	

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

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 29577 bytes --]

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Andrea Arcangeli]

[-- Attachment #1: Type: text/plain, Size: 9805 bytes --]

Hello,

thanks to the report.

Peter, this isn't immediately clear to me, is it perhaps something
related to clang?

This is commit 8dec302e87453234fc7ac1cf4d09e4d577a06cf3

>From 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 Mon Sep 17 00:00:00 2001
From: Andrea Arcangeli <aarcange@redhat.com>
Date: Fri, 7 May 2021 11:05:53 -0400
Subject: [PATCH 1/1] mm: gup: pack has_pinned in MMF_HAS_PINNED

has_pinned 32bit can be packed in the MMF_HAS_PINNED bit as a noop
cleanup.

Any atomic_inc/dec to the mm cacheline shared by all threads in
pin-fast would reintroduce a loss of SMP scalability to pin-fast, so
there's no future potential usefulness to keep an atomic in the mm for
this.

set_bit(MMF_HAS_PINNED) will be theoretically a bit slower than
WRITE_ONCE (atomic_set is equivalent to WRITE_ONCE), but the set_bit
(just like atomic_set after this commit) has to be still issued only
once per "mm", so the difference between the two will be lost in the
noise.

will-it-scale "mmap2" shows no change in performance with enterprise
config as expected.

will-it-scale "pin_fast" retains the > 4000% SMP scalability
performance improvement against upstream as expected.

This is a noop as far as overall performance and SMP scalability are
concerned.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
[peterx: Fix build for task_mmu.c, introduce mm_set_has_pinned_flag, fix
 comment here and there]
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---
 include/linux/mm.h             |  2 +-
 include/linux/mm_types.h       | 10 ----------
 include/linux/sched/coredump.h |  8 ++++++++
 kernel/fork.c                  |  1 -
 mm/gup.c                       | 19 +++++++++++++++----
 5 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5c297b0a97e1..639b3b27ffb7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1352,7 +1352,7 @@ static inline bool page_needs_cow_for_dma(struct vm_area_struct *vma,
 	if (!is_cow_mapping(vma->vm_flags))
 		return false;
 
-	if (!atomic_read(&vma->vm_mm->has_pinned))
+	if (!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))
 		return false;
 
 	return page_maybe_dma_pinned(page);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index ebfece42843c..7fc7a3320ad9 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -441,16 +441,6 @@ struct mm_struct {
 		 */
 		atomic_t mm_count;
 
-		/**
-		 * @has_pinned: Whether this mm has pinned any pages.  This can
-		 * be either replaced in the future by @pinned_vm when it
-		 * becomes stable, or grow into a counter on its own. We're
-		 * aggresive on this bit now - even if the pinned pages were
-		 * unpinned later on, we'll still keep this bit set for the
-		 * lifecycle of this mm just for simplicity.
-		 */
-		atomic_t has_pinned;
-
 		/**
 		 * @write_protect_seq: Locked when any thread is write
 		 * protecting pages mapped by this mm to enforce a later COW,
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index dfd82eab2902..4d9e3a656875 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -73,6 +73,14 @@ static inline int get_dumpable(struct mm_struct *mm)
 #define MMF_OOM_VICTIM		25	/* mm is the oom victim */
 #define MMF_OOM_REAP_QUEUED	26	/* mm was queued for oom_reaper */
 #define MMF_MULTIPROCESS	27	/* mm is shared between processes */
+/*
+ * MMF_HAS_PINNED: Whether this mm has pinned any pages.  This can be either
+ * replaced in the future by mm.pinned_vm when it becomes stable, or grow into
+ * a counter on its own. We're aggresive on this bit for now: even if the
+ * pinned pages were unpinned later on, we'll still keep this bit set for the
+ * lifecycle of this mm, just for simplicity.
+ */
+#define MMF_HAS_PINNED		28	/* FOLL_PIN has run, never cleared */
 #define MMF_DISABLE_THP_MASK	(1 << MMF_DISABLE_THP)
 
 #define MMF_INIT_MASK		(MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\
diff --git a/kernel/fork.c b/kernel/fork.c
index dc06afd725cb..e31541da7dbd 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1029,7 +1029,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 	mm_pgtables_bytes_init(mm);
 	mm->map_count = 0;
 	mm->locked_vm = 0;
-	atomic_set(&mm->has_pinned, 0);
 	atomic64_set(&mm->pinned_vm, 0);
 	memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
 	spin_lock_init(&mm->page_table_lock);
diff --git a/mm/gup.c b/mm/gup.c
index 8ca5e923b54f..d8751840ad0b 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1382,6 +1382,17 @@ int fixup_user_fault(struct mm_struct *mm,
 }
 EXPORT_SYMBOL_GPL(fixup_user_fault);
 
+/*
+ * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
+ * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
+ * cache bouncing on large SMP machines for concurrent pinned gups.
+ */
+static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
+{
+       if (!test_bit(MMF_HAS_PINNED, mm_flags))
+               set_bit(MMF_HAS_PINNED, mm_flags);
+}
+
 /*
  * Please note that this function, unlike __get_user_pages will not
  * return 0 for nr_pages > 0 without FOLL_NOWAIT
@@ -1404,8 +1415,8 @@ static __always_inline long __get_user_pages_locked(struct mm_struct *mm,
 		BUG_ON(*locked != 1);
 	}
 
-	if ((flags & FOLL_PIN) && !atomic_read(&mm->has_pinned))
-		atomic_set(&mm->has_pinned, 1);
+	if (flags & FOLL_PIN)
+		mm_set_has_pinned_flag(&mm->flags);
 
 	/*
 	 * FOLL_PIN and FOLL_GET are mutually exclusive. Traditional behavior
@@ -2741,8 +2752,8 @@ static int internal_get_user_pages_fast(unsigned long start,
 				       FOLL_FAST_ONLY)))
 		return -EINVAL;
 
-	if ((gup_flags & FOLL_PIN) && !atomic_read(&current->mm->has_pinned))
-		atomic_set(&current->mm->has_pinned, 1);
+	if (gup_flags & FOLL_PIN)
+		mm_set_has_pinned_flag(&current->mm->flags);
 
 	if (!(gup_flags & FOLL_FAST_ONLY))
 		might_lock_read(&current->mm->mmap_lock);


On Tue, May 11, 2021 at 06:45:36PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git mapcount_deshare
> head:   3e2f198cce0c1792ad71d6d81974b091019b6483
> commit: 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 [20/27] mm: gup: pack has_pinned in MMF_HAS_PINNED
> config: arm-randconfig-r014-20210511 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
> 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://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=8dec302e87453234fc7ac1cf4d09e4d577a06cf3
>         git remote add aa https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
>         git fetch --no-tags aa mapcount_deshare
>         git checkout 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 
> 
> 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/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag' [-Werror,-Wimplicit-function-declaration]
>                    mm_set_has_pinned_flag(&current->mm->flags);
>                    ^
>    1 error generated.
> 
> 
> vim +/mm_set_has_pinned_flag +2756 mm/gup.c
> 
>   2740	
>   2741	static int internal_get_user_pages_fast(unsigned long start,
>   2742						unsigned long nr_pages,
>   2743						unsigned int gup_flags,
>   2744						struct page **pages)
>   2745	{
>   2746		unsigned long len, end;
>   2747		unsigned long nr_pinned;
>   2748		int ret;
>   2749	
>   2750		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM |
>   2751					       FOLL_FORCE | FOLL_PIN | FOLL_GET |
>   2752					       FOLL_FAST_ONLY)))
>   2753			return -EINVAL;
>   2754	
>   2755		if (gup_flags & FOLL_PIN)
> > 2756			mm_set_has_pinned_flag(&current->mm->flags);
>   2757	
>   2758		if (!(gup_flags & FOLL_FAST_ONLY))
>   2759			might_lock_read(&current->mm->mmap_lock);
>   2760	
>   2761		start = untagged_addr(start) & PAGE_MASK;
>   2762		len = nr_pages << PAGE_SHIFT;
>   2763		if (check_add_overflow(start, len, &end))
>   2764			return 0;
>   2765		if (unlikely(!access_ok((void __user *)start, len)))
>   2766			return -EFAULT;
>   2767	
>   2768		nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
>   2769		if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
>   2770			return nr_pinned;
>   2771	
>   2772		/* Slow path: try to get the remaining pages with get_user_pages */
>   2773		start += nr_pinned << PAGE_SHIFT;
>   2774		pages += nr_pinned;
>   2775		ret = __gup_longterm_unlocked(start, nr_pages - nr_pinned, gup_flags,
>   2776					      pages);
>   2777		if (ret < 0) {
>   2778			/*
>   2779			 * The caller has to unpin the pages we already pinned so
>   2780			 * returning -errno is not an option
>   2781			 */
>   2782			if (nr_pinned)
>   2783				return nr_pinned;
>   2784			return ret;
>   2785		}
>   2786		return ret + nr_pinned;
>   2787	}
>   2788	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Peter Xu]

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On Tue, May 11, 2021 at 08:31:23AM -0400, Andrea Arcangeli wrote:
> Hello,
> 
> thanks to the report.
> 
> Peter, this isn't immediately clear to me, is it perhaps something
> related to clang?
> 
> This is commit 8dec302e87453234fc7ac1cf4d09e4d577a06cf3

Andrea,

I guess it's probably a NOMMU arm config so the helper got opted out as I
errornously put it into a CONFIG_MMU block without noticing..

So we may need to squash below into that commit.

I really should think of something to avoid such errors in the future, as this
is the 2nd time happening at least this year..  Probably I should always start
adding helpers at the beginning of files so I won't overlook any macros..

Thanks,

----8<----
diff --git a/mm/gup.c b/mm/gup.c
index bb130723a6717..0223644d0c61a 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -392,6 +392,17 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
 }
 EXPORT_SYMBOL(unpin_user_pages);
 
+/*
+ * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
+ * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
+ * cache bouncing on large SMP machines for concurrent pinned gups.
+ */
+static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
+{
+       if (!test_bit(MMF_HAS_PINNED, mm_flags))
+               set_bit(MMF_HAS_PINNED, mm_flags);
+}
+
 #ifdef CONFIG_MMU
 static struct page *no_page_table(struct vm_area_struct *vma,
                unsigned int flags)
@@ -1270,17 +1281,6 @@ int fixup_user_fault(struct mm_struct *mm,
 }
 EXPORT_SYMBOL_GPL(fixup_user_fault);
 
-/*
- * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
- * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
- * cache bouncing on large SMP machines for concurrent pinned gups.
- */
-static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
-{
-       if (!test_bit(MMF_HAS_PINNED, mm_flags))
-               set_bit(MMF_HAS_PINNED, mm_flags);
-}
-
 /*
  * Please note that this function, unlike __get_user_pages will not
  * return 0 for nr_pages > 0 without FOLL_NOWAIT
----8<----

-- 
Peter Xu

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Peter Xu]

[-- Attachment #1: Type: text/plain, Size: 2595 bytes --]

On Tue, May 11, 2021 at 10:23:39AM -0400, Peter Xu wrote:
> On Tue, May 11, 2021 at 08:31:23AM -0400, Andrea Arcangeli wrote:
> > Hello,
> > 
> > thanks to the report.
> > 
> > Peter, this isn't immediately clear to me, is it perhaps something
> > related to clang?
> > 
> > This is commit 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> 
> Andrea,
> 
> I guess it's probably a NOMMU arm config so the helper got opted out as I
> errornously put it into a CONFIG_MMU block without noticing..
> 
> So we may need to squash below into that commit.
> 
> I really should think of something to avoid such errors in the future, as this
> is the 2nd time happening at least this year..  Probably I should always start
> adding helpers at the beginning of files so I won't overlook any macros..
> 
> Thanks,
> 
> ----8<----
> diff --git a/mm/gup.c b/mm/gup.c
> index bb130723a6717..0223644d0c61a 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -392,6 +392,17 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
>  }
>  EXPORT_SYMBOL(unpin_user_pages);
>  
> +/*
> + * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
> + * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
> + * cache bouncing on large SMP machines for concurrent pinned gups.
> + */
> +static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
> +{
> +       if (!test_bit(MMF_HAS_PINNED, mm_flags))
> +               set_bit(MMF_HAS_PINNED, mm_flags);
> +}
> +
>  #ifdef CONFIG_MMU
>  static struct page *no_page_table(struct vm_area_struct *vma,
>                 unsigned int flags)
> @@ -1270,17 +1281,6 @@ int fixup_user_fault(struct mm_struct *mm,
>  }
>  EXPORT_SYMBOL_GPL(fixup_user_fault);
>  
> -/*
> - * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
> - * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
> - * cache bouncing on large SMP machines for concurrent pinned gups.
> - */
> -static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
> -{
> -       if (!test_bit(MMF_HAS_PINNED, mm_flags))
> -               set_bit(MMF_HAS_PINNED, mm_flags);
> -}
> -
>  /*
>   * Please note that this function, unlike __get_user_pages will not
>   * return 0 for nr_pages > 0 without FOLL_NOWAIT
> ----8<----

Btw, there's also a space issue with the patch (we need to reindent
mm_set_has_pinned_flag so to use tabs rather than spaces), otherwise checkpatch
seems to complain.  Sorry about both issues!

-- 
Peter Xu

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Andrea Arcangeli]

[-- Attachment #1: Type: text/plain, Size: 2985 bytes --]

On Tue, May 11, 2021 at 10:36:36AM -0400, Peter Xu wrote:
> On Tue, May 11, 2021 at 10:23:39AM -0400, Peter Xu wrote:
> > On Tue, May 11, 2021 at 08:31:23AM -0400, Andrea Arcangeli wrote:
> > > Hello,
> > > 
> > > thanks to the report.
> > > 
> > > Peter, this isn't immediately clear to me, is it perhaps something
> > > related to clang?
> > > 
> > > This is commit 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> > 
> > Andrea,
> > 
> > I guess it's probably a NOMMU arm config so the helper got opted out as I
> > errornously put it into a CONFIG_MMU block without noticing..
> > 
> > So we may need to squash below into that commit.
> > 
> > I really should think of something to avoid such errors in the future, as this
> > is the 2nd time happening at least this year..  Probably I should always start
> > adding helpers at the beginning of files so I won't overlook any macros..
> > 
> > Thanks,
> > 
> > ----8<----
> > diff --git a/mm/gup.c b/mm/gup.c
> > index bb130723a6717..0223644d0c61a 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -392,6 +392,17 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
> >  }
> >  EXPORT_SYMBOL(unpin_user_pages);
> >  
> > +/*
> > + * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
> > + * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
> > + * cache bouncing on large SMP machines for concurrent pinned gups.
> > + */
> > +static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
> > +{
> > +       if (!test_bit(MMF_HAS_PINNED, mm_flags))
> > +               set_bit(MMF_HAS_PINNED, mm_flags);
> > +}
> > +
> >  #ifdef CONFIG_MMU
> >  static struct page *no_page_table(struct vm_area_struct *vma,
> >                 unsigned int flags)
> > @@ -1270,17 +1281,6 @@ int fixup_user_fault(struct mm_struct *mm,
> >  }
> >  EXPORT_SYMBOL_GPL(fixup_user_fault);
> >  
> > -/*
> > - * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's
> > - * lifecycle.  Avoid setting the bit unless necessary, or it might cause write
> > - * cache bouncing on large SMP machines for concurrent pinned gups.
> > - */
> > -static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
> > -{
> > -       if (!test_bit(MMF_HAS_PINNED, mm_flags))
> > -               set_bit(MMF_HAS_PINNED, mm_flags);
> > -}
> > -
> >  /*
> >   * Please note that this function, unlike __get_user_pages will not
> >   * return 0 for nr_pages > 0 without FOLL_NOWAIT
> > ----8<----
> 
> Btw, there's also a space issue with the patch (we need to reindent
> mm_set_has_pinned_flag so to use tabs rather than spaces), otherwise checkpatch
> seems to complain.  Sorry about both issues!

Right, noticed the space issue but I didn't report it because it was
secondary.

Agreed it looks the nommu issue. In the patch the nommu bit didn't
showup since context was missing.

Thanks!
Andrea

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Andrea Arcangeli]

[-- Attachment #1: Type: text/plain, Size: 4083 bytes --]

Hello,

I'm not receiving mails from lkp anymore on my kernel tree for a
while:

https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git

Mostly my interest is in the "main" branch, the other branches aren't
as important to test.

If you disconnected the kernel test robot from my tree it'd be good to
know, alternatively if it's just an glitch if you could correct it, it
would be great.

Thank you,
Andrea

On Tue, May 11, 2021 at 06:45:36PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git mapcount_deshare
> head:   3e2f198cce0c1792ad71d6d81974b091019b6483
> commit: 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 [20/27] mm: gup: pack has_pinned in MMF_HAS_PINNED
> config: arm-randconfig-r014-20210511 (attached as .config)
> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
> 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://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=8dec302e87453234fc7ac1cf4d09e4d577a06cf3
>         git remote add aa https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
>         git fetch --no-tags aa mapcount_deshare
>         git checkout 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 
> 
> 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/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag' [-Werror,-Wimplicit-function-declaration]
>                    mm_set_has_pinned_flag(&current->mm->flags);
>                    ^
>    1 error generated.
> 
> 
> vim +/mm_set_has_pinned_flag +2756 mm/gup.c
> 
>   2740	
>   2741	static int internal_get_user_pages_fast(unsigned long start,
>   2742						unsigned long nr_pages,
>   2743						unsigned int gup_flags,
>   2744						struct page **pages)
>   2745	{
>   2746		unsigned long len, end;
>   2747		unsigned long nr_pinned;
>   2748		int ret;
>   2749	
>   2750		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM |
>   2751					       FOLL_FORCE | FOLL_PIN | FOLL_GET |
>   2752					       FOLL_FAST_ONLY)))
>   2753			return -EINVAL;
>   2754	
>   2755		if (gup_flags & FOLL_PIN)
> > 2756			mm_set_has_pinned_flag(&current->mm->flags);
>   2757	
>   2758		if (!(gup_flags & FOLL_FAST_ONLY))
>   2759			might_lock_read(&current->mm->mmap_lock);
>   2760	
>   2761		start = untagged_addr(start) & PAGE_MASK;
>   2762		len = nr_pages << PAGE_SHIFT;
>   2763		if (check_add_overflow(start, len, &end))
>   2764			return 0;
>   2765		if (unlikely(!access_ok((void __user *)start, len)))
>   2766			return -EFAULT;
>   2767	
>   2768		nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
>   2769		if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
>   2770			return nr_pinned;
>   2771	
>   2772		/* Slow path: try to get the remaining pages with get_user_pages */
>   2773		start += nr_pinned << PAGE_SHIFT;
>   2774		pages += nr_pinned;
>   2775		ret = __gup_longterm_unlocked(start, nr_pages - nr_pinned, gup_flags,
>   2776					      pages);
>   2777		if (ret < 0) {
>   2778			/*
>   2779			 * The caller has to unpin the pages we already pinned so
>   2780			 * returning -errno is not an option
>   2781			 */
>   2782			if (nr_pinned)
>   2783				return nr_pinned;
>   2784			return ret;
>   2785		}
>   2786		return ret + nr_pinned;
>   2787	}
>   2788	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Philip Li]

[-- Attachment #1: Type: text/plain, Size: 4731 bytes --]

On Fri, Dec 17, 2021 at 01:47:08PM -0500, Andrea Arcangeli wrote:
> Hello,
> 
> I'm not receiving mails from lkp anymore on my kernel tree for a
> while:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
> 
> Mostly my interest is in the "main" branch, the other branches aren't
> as important to test.
> 
> If you disconnected the kernel test robot from my tree it'd be good to
> know, alternatively if it's just an glitch if you could correct it, it
> would be great.

Sorry Andrea about this, we will check internally to see what went wrong.
We will not disconnect any repo, and this should be some bug.

Hi Yujie, can you help to check and resolve this?

Thanks

> 
> Thank you,
> Andrea
> 
> On Tue, May 11, 2021 at 06:45:36PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git mapcount_deshare
> > head:   3e2f198cce0c1792ad71d6d81974b091019b6483
> > commit: 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 [20/27] mm: gup: pack has_pinned in MMF_HAS_PINNED
> > config: arm-randconfig-r014-20210511 (attached as .config)
> > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
> > 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://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> >         git remote add aa https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
> >         git fetch --no-tags aa mapcount_deshare
> >         git checkout 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 
> > 
> > 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/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag' [-Werror,-Wimplicit-function-declaration]
> >                    mm_set_has_pinned_flag(&current->mm->flags);
> >                    ^
> >    1 error generated.
> > 
> > 
> > vim +/mm_set_has_pinned_flag +2756 mm/gup.c
> > 
> >   2740	
> >   2741	static int internal_get_user_pages_fast(unsigned long start,
> >   2742						unsigned long nr_pages,
> >   2743						unsigned int gup_flags,
> >   2744						struct page **pages)
> >   2745	{
> >   2746		unsigned long len, end;
> >   2747		unsigned long nr_pinned;
> >   2748		int ret;
> >   2749	
> >   2750		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM |
> >   2751					       FOLL_FORCE | FOLL_PIN | FOLL_GET |
> >   2752					       FOLL_FAST_ONLY)))
> >   2753			return -EINVAL;
> >   2754	
> >   2755		if (gup_flags & FOLL_PIN)
> > > 2756			mm_set_has_pinned_flag(&current->mm->flags);
> >   2757	
> >   2758		if (!(gup_flags & FOLL_FAST_ONLY))
> >   2759			might_lock_read(&current->mm->mmap_lock);
> >   2760	
> >   2761		start = untagged_addr(start) & PAGE_MASK;
> >   2762		len = nr_pages << PAGE_SHIFT;
> >   2763		if (check_add_overflow(start, len, &end))
> >   2764			return 0;
> >   2765		if (unlikely(!access_ok((void __user *)start, len)))
> >   2766			return -EFAULT;
> >   2767	
> >   2768		nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
> >   2769		if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
> >   2770			return nr_pinned;
> >   2771	
> >   2772		/* Slow path: try to get the remaining pages with get_user_pages */
> >   2773		start += nr_pinned << PAGE_SHIFT;
> >   2774		pages += nr_pinned;
> >   2775		ret = __gup_longterm_unlocked(start, nr_pages - nr_pinned, gup_flags,
> >   2776					      pages);
> >   2777		if (ret < 0) {
> >   2778			/*
> >   2779			 * The caller has to unpin the pages we already pinned so
> >   2780			 * returning -errno is not an option
> >   2781			 */
> >   2782			if (nr_pinned)
> >   2783				return nr_pinned;
> >   2784			return ret;
> >   2785		}
> >   2786		return ret + nr_pinned;
> >   2787	}
> >   2788	
> > 
> > ---
> > 0-DAY CI Kernel Test Service, Intel Corporation
> > https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
> 
> _______________________________________________
> kbuild-all mailing list -- kbuild-all(a)lists.01.org
> To unsubscribe send an email to kbuild-all-leave(a)lists.01.org

Re: [aa:mapcount_deshare 20/27] mm/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag'

[Andrea Arcangeli]

[-- Attachment #1: Type: text/plain, Size: 5310 bytes --]

Hi Philip,

On Sat, Dec 18, 2021 at 08:30:24PM +0800, Philip Li wrote:
> On Fri, Dec 17, 2021 at 01:47:08PM -0500, Andrea Arcangeli wrote:
> > Hello,
> > 
> > I'm not receiving mails from lkp anymore on my kernel tree for a
> > while:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
> > 
> > Mostly my interest is in the "main" branch, the other branches aren't
> > as important to test.
> > 
> > If you disconnected the kernel test robot from my tree it'd be good to
> > know, alternatively if it's just an glitch if you could correct it, it
> > would be great.
> 
> Sorry Andrea about this, we will check internally to see what went wrong.
> We will not disconnect any repo, and this should be some bug.

This is great news. Thanks a lot for checking!

I shall specify that it might be possible that it's still running,
perhaps I simply triggered no emails over the last months despite
adding various updates, but I thought of asking just in case.

Thanks,
Andrea

> 
> Hi Yujie, can you help to check and resolve this?
> 
> Thanks
> 
> > 
> > Thank you,
> > Andrea
> > 
> > On Tue, May 11, 2021 at 06:45:36PM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git mapcount_deshare
> > > head:   3e2f198cce0c1792ad71d6d81974b091019b6483
> > > commit: 8dec302e87453234fc7ac1cf4d09e4d577a06cf3 [20/27] mm: gup: pack has_pinned in MMF_HAS_PINNED
> > > config: arm-randconfig-r014-20210511 (attached as .config)
> > > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
> > > 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://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git/commit/?id=8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> > >         git remote add aa https://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
> > >         git fetch --no-tags aa mapcount_deshare
> > >         git checkout 8dec302e87453234fc7ac1cf4d09e4d577a06cf3
> > >         # save the attached .config to linux build tree
> > >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm 
> > > 
> > > 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/gup.c:2756:3: error: implicit declaration of function 'mm_set_has_pinned_flag' [-Werror,-Wimplicit-function-declaration]
> > >                    mm_set_has_pinned_flag(&current->mm->flags);
> > >                    ^
> > >    1 error generated.
> > > 
> > > 
> > > vim +/mm_set_has_pinned_flag +2756 mm/gup.c
> > > 
> > >   2740	
> > >   2741	static int internal_get_user_pages_fast(unsigned long start,
> > >   2742						unsigned long nr_pages,
> > >   2743						unsigned int gup_flags,
> > >   2744						struct page **pages)
> > >   2745	{
> > >   2746		unsigned long len, end;
> > >   2747		unsigned long nr_pinned;
> > >   2748		int ret;
> > >   2749	
> > >   2750		if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM |
> > >   2751					       FOLL_FORCE | FOLL_PIN | FOLL_GET |
> > >   2752					       FOLL_FAST_ONLY)))
> > >   2753			return -EINVAL;
> > >   2754	
> > >   2755		if (gup_flags & FOLL_PIN)
> > > > 2756			mm_set_has_pinned_flag(&current->mm->flags);
> > >   2757	
> > >   2758		if (!(gup_flags & FOLL_FAST_ONLY))
> > >   2759			might_lock_read(&current->mm->mmap_lock);
> > >   2760	
> > >   2761		start = untagged_addr(start) & PAGE_MASK;
> > >   2762		len = nr_pages << PAGE_SHIFT;
> > >   2763		if (check_add_overflow(start, len, &end))
> > >   2764			return 0;
> > >   2765		if (unlikely(!access_ok((void __user *)start, len)))
> > >   2766			return -EFAULT;
> > >   2767	
> > >   2768		nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
> > >   2769		if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
> > >   2770			return nr_pinned;
> > >   2771	
> > >   2772		/* Slow path: try to get the remaining pages with get_user_pages */
> > >   2773		start += nr_pinned << PAGE_SHIFT;
> > >   2774		pages += nr_pinned;
> > >   2775		ret = __gup_longterm_unlocked(start, nr_pages - nr_pinned, gup_flags,
> > >   2776					      pages);
> > >   2777		if (ret < 0) {
> > >   2778			/*
> > >   2779			 * The caller has to unpin the pages we already pinned so
> > >   2780			 * returning -errno is not an option
> > >   2781			 */
> > >   2782			if (nr_pinned)
> > >   2783				return nr_pinned;
> > >   2784			return ret;
> > >   2785		}
> > >   2786		return ret + nr_pinned;
> > >   2787	}
> > >   2788	
> > > 
> > > ---
> > > 0-DAY CI Kernel Test Service, Intel Corporation
> > > https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
> > 
> > _______________________________________________
> > kbuild-all mailing list -- kbuild-all(a)lists.01.org
> > To unsubscribe send an email to kbuild-all-leave(a)lists.01.org
>