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2021-04-21 Thread SALES 
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Re: [Virtio-fs] [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry()

2021-04-21 Thread Vivek Goyal 
On Wed, Apr 21, 2021 at 12:09:54PM -0700, Dan Williams wrote:
> On Tue, Apr 20, 2021 at 7:01 AM Vivek Goyal  wrote:
> >
> > On Tue, Apr 20, 2021 at 09:34:20AM +0200, Greg Kurz wrote:
> > > On Mon, 19 Apr 2021 17:36:35 -0400
> > > Vivek Goyal  wrote:
> > >
> > > > As of now put_unlocked_entry() always wakes up next waiter. In next
> > > > patches we want to wake up all waiters at one callsite. Hence, add a
> > > > parameter to the function.
> > > >
> > > > This patch does not introduce any change of behavior.
> > > >
> > > > Suggested-by: Dan Williams 
> > > > Signed-off-by: Vivek Goyal 
> > > > ---
> > > >  fs/dax.c | 13 +++--
> > > >  1 file changed, 7 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/fs/dax.c b/fs/dax.c
> > > > index 00978d0838b1..f19d76a6a493 100644
> > > > --- a/fs/dax.c
> > > > +++ b/fs/dax.c
> > > > @@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state 
> > > > *xas, void *entry)
> > > > finish_wait(wq, );
> > > >  }
> > > >
> > > > -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> > > > +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> > > > +  enum dax_entry_wake_mode mode)
> > > >  {
> > > > /* If we were the only waiter woken, wake the next one */
> > >
> > > With this change, the comment is no longer accurate since the
> > > function can now wake all waiters if passed mode == WAKE_ALL.
> > > Also, it paraphrases the code which is simple enough, so I'd
> > > simply drop it.
> > >
> > > This is minor though and it shouldn't prevent this fix to go
> > > forward.
> > >
> > > Reviewed-by: Greg Kurz 
> >
> > Ok, here is the updated patch which drops that comment line.
> >
> > Vivek
> 
> Hi Vivek,
> 
> Can you get in the habit of not replying inline with new patches like
> this? Collect the review feedback, take a pause, and resend the full
> series so tooling like b4 and patchwork can track when a new posting
> supersedes a previous one. As is, this inline style inflicts manual
> effort on the maintainer.

Hi Dan,

Sure. I will avoid doing this updated inline patch style. I will post new
version of patch series. 

Thanks
Vivek

> 
> >
> > Subject: dax: Add a wakeup mode parameter to put_unlocked_entry()
> >
> > As of now put_unlocked_entry() always wakes up next waiter. In next
> > patches we want to wake up all waiters at one callsite. Hence, add a
> > parameter to the function.
> >
> > This patch does not introduce any change of behavior.
> >
> > Suggested-by: Dan Williams 
> > Signed-off-by: Vivek Goyal 
> > ---
> >  fs/dax.c |   14 +++---
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > Index: redhat-linux/fs/dax.c
> > ===
> > --- redhat-linux.orig/fs/dax.c  2021-04-20 09:55:45.105069893 -0400
> > +++ redhat-linux/fs/dax.c   2021-04-20 09:56:27.685822730 -0400
> > @@ -275,11 +275,11 @@ static void wait_entry_unlocked(struct x
> > finish_wait(wq, );
> >  }
> >
> > -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> > +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> > +  enum dax_entry_wake_mode mode)
> >  {
> > -   /* If we were the only waiter woken, wake the next one */
> > if (entry && !dax_is_conflict(entry))
> > -   dax_wake_entry(xas, entry, WAKE_NEXT);
> > +   dax_wake_entry(xas, entry, mode);
> >  }
> >
> >  /*
> > @@ -633,7 +633,7 @@ struct page *dax_layout_busy_page_range(
> > entry = get_unlocked_entry(, 0);
> > if (entry)
> > page = dax_busy_page(entry);
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > if (page)
> > break;
> > if (++scanned % XA_CHECK_SCHED)
> > @@ -675,7 +675,7 @@ static int __dax_invalidate_entry(struct
> > mapping->nrexceptional--;
> > ret = 1;
> >  out:
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > xas_unlock_irq();
> > return ret;
> >  }
> > @@ -954,7 +954,7 @@ static int dax_writeback_one(struct xa_s
> > return ret;
> >
> >   put_unlocked:
> > -   put_unlocked_entry(xas, entry);
> > +   put_unlocked_entry(xas, entry, WAKE_NEXT);
> > return ret;
> >  }
> >
> > @@ -1695,7 +1695,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *
> > /* Did we race with someone splitting entry or so? */
> > if (!entry || dax_is_conflict(entry) ||
> > (order == 0 && !dax_is_pte_entry(entry))) {
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > xas_unlock_irq();
> > trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
> >

Re: [Virtio-fs] [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry()

2021-04-21 Thread Dan Williams 
On Tue, Apr 20, 2021 at 7:01 AM Vivek Goyal  wrote:
>
> On Tue, Apr 20, 2021 at 09:34:20AM +0200, Greg Kurz wrote:
> > On Mon, 19 Apr 2021 17:36:35 -0400
> > Vivek Goyal  wrote:
> >
> > > As of now put_unlocked_entry() always wakes up next waiter. In next
> > > patches we want to wake up all waiters at one callsite. Hence, add a
> > > parameter to the function.
> > >
> > > This patch does not introduce any change of behavior.
> > >
> > > Suggested-by: Dan Williams 
> > > Signed-off-by: Vivek Goyal 
> > > ---
> > >  fs/dax.c | 13 +++--
> > >  1 file changed, 7 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/fs/dax.c b/fs/dax.c
> > > index 00978d0838b1..f19d76a6a493 100644
> > > --- a/fs/dax.c
> > > +++ b/fs/dax.c
> > > @@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state 
> > > *xas, void *entry)
> > > finish_wait(wq, );
> > >  }
> > >
> > > -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> > > +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> > > +  enum dax_entry_wake_mode mode)
> > >  {
> > > /* If we were the only waiter woken, wake the next one */
> >
> > With this change, the comment is no longer accurate since the
> > function can now wake all waiters if passed mode == WAKE_ALL.
> > Also, it paraphrases the code which is simple enough, so I'd
> > simply drop it.
> >
> > This is minor though and it shouldn't prevent this fix to go
> > forward.
> >
> > Reviewed-by: Greg Kurz 
>
> Ok, here is the updated patch which drops that comment line.
>
> Vivek

Hi Vivek,

Can you get in the habit of not replying inline with new patches like
this? Collect the review feedback, take a pause, and resend the full
series so tooling like b4 and patchwork can track when a new posting
supersedes a previous one. As is, this inline style inflicts manual
effort on the maintainer.

>
> Subject: dax: Add a wakeup mode parameter to put_unlocked_entry()
>
> As of now put_unlocked_entry() always wakes up next waiter. In next
> patches we want to wake up all waiters at one callsite. Hence, add a
> parameter to the function.
>
> This patch does not introduce any change of behavior.
>
> Suggested-by: Dan Williams 
> Signed-off-by: Vivek Goyal 
> ---
>  fs/dax.c |   14 +++---
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> Index: redhat-linux/fs/dax.c
> ===
> --- redhat-linux.orig/fs/dax.c  2021-04-20 09:55:45.105069893 -0400
> +++ redhat-linux/fs/dax.c   2021-04-20 09:56:27.685822730 -0400
> @@ -275,11 +275,11 @@ static void wait_entry_unlocked(struct x
> finish_wait(wq, );
>  }
>
> -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> +  enum dax_entry_wake_mode mode)
>  {
> -   /* If we were the only waiter woken, wake the next one */
> if (entry && !dax_is_conflict(entry))
> -   dax_wake_entry(xas, entry, WAKE_NEXT);
> +   dax_wake_entry(xas, entry, mode);
>  }
>
>  /*
> @@ -633,7 +633,7 @@ struct page *dax_layout_busy_page_range(
> entry = get_unlocked_entry(, 0);
> if (entry)
> page = dax_busy_page(entry);
> -   put_unlocked_entry(, entry);
> +   put_unlocked_entry(, entry, WAKE_NEXT);
> if (page)
> break;
> if (++scanned % XA_CHECK_SCHED)
> @@ -675,7 +675,7 @@ static int __dax_invalidate_entry(struct
> mapping->nrexceptional--;
> ret = 1;
>  out:
> -   put_unlocked_entry(, entry);
> +   put_unlocked_entry(, entry, WAKE_NEXT);
> xas_unlock_irq();
> return ret;
>  }
> @@ -954,7 +954,7 @@ static int dax_writeback_one(struct xa_s
> return ret;
>
>   put_unlocked:
> -   put_unlocked_entry(xas, entry);
> +   put_unlocked_entry(xas, entry, WAKE_NEXT);
> return ret;
>  }
>
> @@ -1695,7 +1695,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *
> /* Did we race with someone splitting entry or so? */
> if (!entry || dax_is_conflict(entry) ||
> (order == 0 && !dax_is_pte_entry(entry))) {
> -   put_unlocked_entry(, entry);
> +   put_unlocked_entry(, entry, WAKE_NEXT);
> xas_unlock_irq();
> trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
>   VM_FAULT_NOPAGE);
>
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Re: [Virtio-fs] [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry()

2021-04-21 Thread Vivek Goyal 
On Tue, Apr 20, 2021 at 09:34:20AM +0200, Greg Kurz wrote:
> On Mon, 19 Apr 2021 17:36:35 -0400
> Vivek Goyal  wrote:
> 
> > As of now put_unlocked_entry() always wakes up next waiter. In next
> > patches we want to wake up all waiters at one callsite. Hence, add a
> > parameter to the function.
> > 
> > This patch does not introduce any change of behavior.
> > 
> > Suggested-by: Dan Williams 
> > Signed-off-by: Vivek Goyal 
> > ---
> >  fs/dax.c | 13 +++--
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> > 
> > diff --git a/fs/dax.c b/fs/dax.c
> > index 00978d0838b1..f19d76a6a493 100644
> > --- a/fs/dax.c
> > +++ b/fs/dax.c
> > @@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state *xas, 
> > void *entry)
> > finish_wait(wq, );
> >  }
> >  
> > -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> > +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> > +  enum dax_entry_wake_mode mode)
> >  {
> > /* If we were the only waiter woken, wake the next one */
> 
> With this change, the comment is no longer accurate since the
> function can now wake all waiters if passed mode == WAKE_ALL.
> Also, it paraphrases the code which is simple enough, so I'd
> simply drop it.

Ok, I will get rid of this comment. Agreed that code is simple
enough. And frankly speaking I don't even understand "If we were the
only waiter woken" part. How do we know that only this caller
was woken.

Vivek

> 
> This is minor though and it shouldn't prevent this fix to go
> forward.
> 
> Reviewed-by: Greg Kurz 
> 
> > if (entry && !dax_is_conflict(entry))
> > -   dax_wake_entry(xas, entry, WAKE_NEXT);
> > +   dax_wake_entry(xas, entry, mode);
> >  }
> >  
> >  /*
> > @@ -633,7 +634,7 @@ struct page *dax_layout_busy_page_range(struct 
> > address_space *mapping,
> > entry = get_unlocked_entry(, 0);
> > if (entry)
> > page = dax_busy_page(entry);
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > if (page)
> > break;
> > if (++scanned % XA_CHECK_SCHED)
> > @@ -675,7 +676,7 @@ static int __dax_invalidate_entry(struct address_space 
> > *mapping,
> > mapping->nrexceptional--;
> > ret = 1;
> >  out:
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > xas_unlock_irq();
> > return ret;
> >  }
> > @@ -954,7 +955,7 @@ static int dax_writeback_one(struct xa_state *xas, 
> > struct dax_device *dax_dev,
> > return ret;
> >  
> >   put_unlocked:
> > -   put_unlocked_entry(xas, entry);
> > +   put_unlocked_entry(xas, entry, WAKE_NEXT);
> > return ret;
> >  }
> >  
> > @@ -1695,7 +1696,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t 
> > pfn, unsigned int order)
> > /* Did we race with someone splitting entry or so? */
> > if (!entry || dax_is_conflict(entry) ||
> > (order == 0 && !dax_is_pte_entry(entry))) {
> > -   put_unlocked_entry(, entry);
> > +   put_unlocked_entry(, entry, WAKE_NEXT);
> > xas_unlock_irq();
> > trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
> >   VM_FAULT_NOPAGE);
> 
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Re: [PATCH v3 1/3] dax: Add an enum for specifying dax wakup mode

2021-04-21 Thread Vivek Goyal 
On Wed, Apr 21, 2021 at 05:16:24PM +0100, Matthew Wilcox wrote:
> On Wed, Apr 21, 2021 at 11:56:31AM -0400, Vivek Goyal wrote:
> > +/**
> > + * enum dax_entry_wake_mode: waitqueue wakeup toggle
> 
> s/toggle/behaviour/ ?

Will do.

> 
> > + * @WAKE_NEXT: wake only the first waiter in the waitqueue
> > + * @WAKE_ALL: wake all waiters in the waitqueue
> > + */
> > +enum dax_entry_wake_mode {
> > +   WAKE_NEXT,
> > +   WAKE_ALL,
> > +};
> > +
> >  static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas,
> > void *entry, struct exceptional_entry_key *key)
> >  {
> > @@ -182,7 +192,8 @@ static int wake_exceptional_entry_func(w
> >   * The important information it's conveying is whether the entry at
> >   * this index used to be a PMD entry.
> >   */
> > -static void dax_wake_entry(struct xa_state *xas, void *entry, bool 
> > wake_all)
> > +static void dax_wake_entry(struct xa_state *xas, void *entry,
> > +  enum dax_entry_wake_mode mode)
> 
> It's an awfully verbose name.  'dax_wake_mode'?

Sure. Will change.

Vivek
> 
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Re: [PATCH v3 1/3] dax: Add an enum for specifying dax wakup mode

2021-04-21 Thread Matthew Wilcox 
On Wed, Apr 21, 2021 at 11:56:31AM -0400, Vivek Goyal wrote:
> +/**
> + * enum dax_entry_wake_mode: waitqueue wakeup toggle

s/toggle/behaviour/ ?

> + * @WAKE_NEXT: wake only the first waiter in the waitqueue
> + * @WAKE_ALL: wake all waiters in the waitqueue
> + */
> +enum dax_entry_wake_mode {
> + WAKE_NEXT,
> + WAKE_ALL,
> +};
> +
>  static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas,
>   void *entry, struct exceptional_entry_key *key)
>  {
> @@ -182,7 +192,8 @@ static int wake_exceptional_entry_func(w
>   * The important information it's conveying is whether the entry at
>   * this index used to be a PMD entry.
>   */
> -static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all)
> +static void dax_wake_entry(struct xa_state *xas, void *entry,
> +enum dax_entry_wake_mode mode)

It's an awfully verbose name.  'dax_wake_mode'?
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Re: [PATCH v3 1/3] dax: Add an enum for specifying dax wakup mode

2021-04-21 Thread Vivek Goyal 
On Wed, Apr 21, 2021 at 11:24:40AM +0200, Jan Kara wrote:
> On Mon 19-04-21 17:36:34, Vivek Goyal wrote:
> > Dan mentioned that he is not very fond of passing around a boolean 
> > true/false
> > to specify if only next waiter should be woken up or all waiters should be
> > woken up. He instead prefers that we introduce an enum and make it very
> > explicity at the callsite itself. Easier to read code.
> > 
> > This patch should not introduce any change of behavior.
> > 
> > Suggested-by: Dan Williams 
> > Signed-off-by: Vivek Goyal 
> > ---
> >  fs/dax.c | 23 +--
> >  1 file changed, 17 insertions(+), 6 deletions(-)
> > 
> > diff --git a/fs/dax.c b/fs/dax.c
> > index b3d27fdc6775..00978d0838b1 100644
> > --- a/fs/dax.c
> > +++ b/fs/dax.c
> > @@ -144,6 +144,16 @@ struct wait_exceptional_entry_queue {
> > struct exceptional_entry_key key;
> >  };
> >  
> > +/**
> > + * enum dax_entry_wake_mode: waitqueue wakeup toggle
> > + * @WAKE_NEXT: entry was not mutated
> > + * @WAKE_ALL: entry was invalidated, or resized
> 
> Let's document the constants in terms of what they do, not when they are
> expected to be called. So something like:
> 
> @WAKE_NEXT: wake only the first waiter in the waitqueue
> @WAKE_ALL: wake all waiters in the waitqueue
> 
> Otherwise the patch looks good so feel free to add:
> 
> Reviewed-by: Jan Kara 
> 

Hi Jan,

Here is the updated patch based on your feedback.

Thanks
Vivek


Subject: dax: Add an enum for specifying dax wakup mode

Dan mentioned that he is not very fond of passing around a boolean true/false
to specify if only next waiter should be woken up or all waiters should be
woken up. He instead prefers that we introduce an enum and make it very
explicity at the callsite itself. Easier to read code.

This patch should not introduce any change of behavior.

Suggested-by: Dan Williams 
Signed-off-by: Vivek Goyal 
---
 fs/dax.c |   23 +--
 1 file changed, 17 insertions(+), 6 deletions(-)

Index: redhat-linux/fs/dax.c
===
--- redhat-linux.orig/fs/dax.c  2021-04-21 11:51:04.716289502 -0400
+++ redhat-linux/fs/dax.c   2021-04-21 11:52:10.298010850 -0400
@@ -144,6 +144,16 @@ struct wait_exceptional_entry_queue {
struct exceptional_entry_key key;
 };
 
+/**
+ * enum dax_entry_wake_mode: waitqueue wakeup toggle
+ * @WAKE_NEXT: wake only the first waiter in the waitqueue
+ * @WAKE_ALL: wake all waiters in the waitqueue
+ */
+enum dax_entry_wake_mode {
+   WAKE_NEXT,
+   WAKE_ALL,
+};
+
 static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas,
void *entry, struct exceptional_entry_key *key)
 {
@@ -182,7 +192,8 @@ static int wake_exceptional_entry_func(w
  * The important information it's conveying is whether the entry at
  * this index used to be a PMD entry.
  */
-static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all)
+static void dax_wake_entry(struct xa_state *xas, void *entry,
+  enum dax_entry_wake_mode mode)
 {
struct exceptional_entry_key key;
wait_queue_head_t *wq;
@@ -196,7 +207,7 @@ static void dax_wake_entry(struct xa_sta
 * must be in the waitqueue and the following check will see them.
 */
if (waitqueue_active(wq))
-   __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, );
+   __wake_up(wq, TASK_NORMAL, mode == WAKE_ALL ? 0 : 1, );
 }
 
 /*
@@ -268,7 +279,7 @@ static void put_unlocked_entry(struct xa
 {
/* If we were the only waiter woken, wake the next one */
if (entry && !dax_is_conflict(entry))
-   dax_wake_entry(xas, entry, false);
+   dax_wake_entry(xas, entry, WAKE_NEXT);
 }
 
 /*
@@ -286,7 +297,7 @@ static void dax_unlock_entry(struct xa_s
old = xas_store(xas, entry);
xas_unlock_irq(xas);
BUG_ON(!dax_is_locked(old));
-   dax_wake_entry(xas, entry, false);
+   dax_wake_entry(xas, entry, WAKE_NEXT);
 }
 
 /*
@@ -524,7 +535,7 @@ retry:
 
dax_disassociate_entry(entry, mapping, false);
xas_store(xas, NULL);   /* undo the PMD join */
-   dax_wake_entry(xas, entry, true);
+   dax_wake_entry(xas, entry, WAKE_ALL);
mapping->nrexceptional--;
entry = NULL;
xas_set(xas, index);
@@ -937,7 +948,7 @@ static int dax_writeback_one(struct xa_s
xas_lock_irq(xas);
xas_store(xas, entry);
xas_clear_mark(xas, PAGECACHE_TAG_DIRTY);
-   dax_wake_entry(xas, entry, false);
+   dax_wake_entry(xas, entry, WAKE_NEXT);
 
trace_dax_writeback_one(mapping->host, index, count);
return ret;
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Re: [PATCH v3 3/3] dax: Wake up all waiters after invalidating dax entry

2021-04-21 Thread Jan Kara 
On Mon 19-04-21 17:36:36, Vivek Goyal wrote:
> I am seeing missed wakeups which ultimately lead to a deadlock when I am
> using virtiofs with DAX enabled and running "make -j". I had to mount
> virtiofs as rootfs and also reduce to dax window size to 256M to reproduce
> the problem consistently.
> 
> So here is the problem. put_unlocked_entry() wakes up waiters only
> if entry is not null as well as !dax_is_conflict(entry). But if I
> call multiple instances of invalidate_inode_pages2() in parallel,
> then I can run into a situation where there are waiters on
> this index but nobody will wait these.
> 
> invalidate_inode_pages2()
>   invalidate_inode_pages2_range()
> invalidate_exceptional_entry2()
>   dax_invalidate_mapping_entry_sync()
> __dax_invalidate_entry() {
> xas_lock_irq();
> entry = get_unlocked_entry(, 0);
> ...
> ...
> dax_disassociate_entry(entry, mapping, trunc);
> xas_store(, NULL);
> ...
> ...
> put_unlocked_entry(, entry);
> xas_unlock_irq();
> }
> 
> Say a fault in in progress and it has locked entry at offset say "0x1c".
> Now say three instances of invalidate_inode_pages2() are in progress
> (A, B, C) and they all try to invalidate entry at offset "0x1c". Given
> dax entry is locked, all tree instances A, B, C will wait in wait queue.
> 
> When dax fault finishes, say A is woken up. It will store NULL entry
> at index "0x1c" and wake up B. When B comes along it will find "entry=0"
> at page offset 0x1c and it will call put_unlocked_entry(, 0). And
> this means put_unlocked_entry() will not wake up next waiter, given
> the current code. And that means C continues to wait and is not woken
> up.
> 
> This patch fixes the issue by waking up all waiters when a dax entry
> has been invalidated. This seems to fix the deadlock I am facing
> and I can make forward progress.
> 
> Reported-by: Sergio Lopez 
> Fixes: ac401cc78242 ("dax: New fault locking")
> Suggested-by: Dan Williams 
> Signed-off-by: Vivek Goyal 

Looks good to me. Thanks for fixing this! Feel free to add:

Reviewed-by: Jan Kara 

Honza

> ---
>  fs/dax.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index f19d76a6a493..cc497519be83 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -676,7 +676,7 @@ static int __dax_invalidate_entry(struct address_space 
> *mapping,
>   mapping->nrexceptional--;
>   ret = 1;
>  out:
> - put_unlocked_entry(, entry, WAKE_NEXT);
> + put_unlocked_entry(, entry, WAKE_ALL);
>   xas_unlock_irq();
>   return ret;
>  }
> -- 
> 2.25.4
> 
-- 
Jan Kara 
SUSE Labs, CR
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Re: [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry()

2021-04-21 Thread Jan Kara 
On Mon 19-04-21 17:36:35, Vivek Goyal wrote:
> As of now put_unlocked_entry() always wakes up next waiter. In next
> patches we want to wake up all waiters at one callsite. Hence, add a
> parameter to the function.
> 
> This patch does not introduce any change of behavior.
> 
> Suggested-by: Dan Williams 
> Signed-off-by: Vivek Goyal 

Looks good. You can add:

Reviewed-by: Jan Kara 

Honza

> ---
>  fs/dax.c | 13 +++--
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 00978d0838b1..f19d76a6a493 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state *xas, 
> void *entry)
>   finish_wait(wq, );
>  }
>  
> -static void put_unlocked_entry(struct xa_state *xas, void *entry)
> +static void put_unlocked_entry(struct xa_state *xas, void *entry,
> +enum dax_entry_wake_mode mode)
>  {
>   /* If we were the only waiter woken, wake the next one */
>   if (entry && !dax_is_conflict(entry))
> - dax_wake_entry(xas, entry, WAKE_NEXT);
> + dax_wake_entry(xas, entry, mode);
>  }
>  
>  /*
> @@ -633,7 +634,7 @@ struct page *dax_layout_busy_page_range(struct 
> address_space *mapping,
>   entry = get_unlocked_entry(, 0);
>   if (entry)
>   page = dax_busy_page(entry);
> - put_unlocked_entry(, entry);
> + put_unlocked_entry(, entry, WAKE_NEXT);
>   if (page)
>   break;
>   if (++scanned % XA_CHECK_SCHED)
> @@ -675,7 +676,7 @@ static int __dax_invalidate_entry(struct address_space 
> *mapping,
>   mapping->nrexceptional--;
>   ret = 1;
>  out:
> - put_unlocked_entry(, entry);
> + put_unlocked_entry(, entry, WAKE_NEXT);
>   xas_unlock_irq();
>   return ret;
>  }
> @@ -954,7 +955,7 @@ static int dax_writeback_one(struct xa_state *xas, struct 
> dax_device *dax_dev,
>   return ret;
>  
>   put_unlocked:
> - put_unlocked_entry(xas, entry);
> + put_unlocked_entry(xas, entry, WAKE_NEXT);
>   return ret;
>  }
>  
> @@ -1695,7 +1696,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, 
> unsigned int order)
>   /* Did we race with someone splitting entry or so? */
>   if (!entry || dax_is_conflict(entry) ||
>   (order == 0 && !dax_is_pte_entry(entry))) {
> - put_unlocked_entry(, entry);
> + put_unlocked_entry(, entry, WAKE_NEXT);
>   xas_unlock_irq();
>   trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
> VM_FAULT_NOPAGE);
> -- 
> 2.25.4
> 
-- 
Jan Kara 
SUSE Labs, CR
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Re: [PATCH v3 1/3] dax: Add an enum for specifying dax wakup mode

2021-04-21 Thread Jan Kara 
On Mon 19-04-21 17:36:34, Vivek Goyal wrote:
> Dan mentioned that he is not very fond of passing around a boolean true/false
> to specify if only next waiter should be woken up or all waiters should be
> woken up. He instead prefers that we introduce an enum and make it very
> explicity at the callsite itself. Easier to read code.
> 
> This patch should not introduce any change of behavior.
> 
> Suggested-by: Dan Williams 
> Signed-off-by: Vivek Goyal 
> ---
>  fs/dax.c | 23 +--
>  1 file changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index b3d27fdc6775..00978d0838b1 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -144,6 +144,16 @@ struct wait_exceptional_entry_queue {
>   struct exceptional_entry_key key;
>  };
>  
> +/**
> + * enum dax_entry_wake_mode: waitqueue wakeup toggle
> + * @WAKE_NEXT: entry was not mutated
> + * @WAKE_ALL: entry was invalidated, or resized

Let's document the constants in terms of what they do, not when they are
expected to be called. So something like:

@WAKE_NEXT: wake only the first waiter in the waitqueue
@WAKE_ALL: wake all waiters in the waitqueue

Otherwise the patch looks good so feel free to add:

Reviewed-by: Jan Kara 

Honza

> + */
> +enum dax_entry_wake_mode {
> + WAKE_NEXT,
> + WAKE_ALL,
> +};
> +
>  static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas,
>   void *entry, struct exceptional_entry_key *key)
>  {
> @@ -182,7 +192,8 @@ static int wake_exceptional_entry_func(wait_queue_entry_t 
> *wait,
>   * The important information it's conveying is whether the entry at
>   * this index used to be a PMD entry.
>   */
> -static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all)
> +static void dax_wake_entry(struct xa_state *xas, void *entry,
> +enum dax_entry_wake_mode mode)
>  {
>   struct exceptional_entry_key key;
>   wait_queue_head_t *wq;
> @@ -196,7 +207,7 @@ static void dax_wake_entry(struct xa_state *xas, void 
> *entry, bool wake_all)
>* must be in the waitqueue and the following check will see them.
>*/
>   if (waitqueue_active(wq))
> - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, );
> + __wake_up(wq, TASK_NORMAL, mode == WAKE_ALL ? 0 : 1, );
>  }
>  
>  /*
> @@ -268,7 +279,7 @@ static void put_unlocked_entry(struct xa_state *xas, void 
> *entry)
>  {
>   /* If we were the only waiter woken, wake the next one */
>   if (entry && !dax_is_conflict(entry))
> - dax_wake_entry(xas, entry, false);
> + dax_wake_entry(xas, entry, WAKE_NEXT);
>  }
>  
>  /*
> @@ -286,7 +297,7 @@ static void dax_unlock_entry(struct xa_state *xas, void 
> *entry)
>   old = xas_store(xas, entry);
>   xas_unlock_irq(xas);
>   BUG_ON(!dax_is_locked(old));
> - dax_wake_entry(xas, entry, false);
> + dax_wake_entry(xas, entry, WAKE_NEXT);
>  }
>  
>  /*
> @@ -524,7 +535,7 @@ static void *grab_mapping_entry(struct xa_state *xas,
>  
>   dax_disassociate_entry(entry, mapping, false);
>   xas_store(xas, NULL);   /* undo the PMD join */
> - dax_wake_entry(xas, entry, true);
> + dax_wake_entry(xas, entry, WAKE_ALL);
>   mapping->nrexceptional--;
>   entry = NULL;
>   xas_set(xas, index);
> @@ -937,7 +948,7 @@ static int dax_writeback_one(struct xa_state *xas, struct 
> dax_device *dax_dev,
>   xas_lock_irq(xas);
>   xas_store(xas, entry);
>   xas_clear_mark(xas, PAGECACHE_TAG_DIRTY);
> - dax_wake_entry(xas, entry, false);
> + dax_wake_entry(xas, entry, WAKE_NEXT);
>  
>   trace_dax_writeback_one(mapping->host, index, count);
>   return ret;
> -- 
> 2.25.4
> 
-- 
Jan Kara 
SUSE Labs, CR
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Request for Quotation (RFQ)

2021-04-21 Thread PFIZER B . V Supply 
Good Day Sir/Madam,

We are please to invite you or your company to quote the following item listed
below:

Product/Model No: Cetter Actuator model 275
Model Number: 275
Qty. 45

Compulsory,Kindly send your quotation to: 
qu...@pfizereu.com
for immediate approval.

Kind Regards,
Ajane Bulla
PFIZER B.V Supply Chain Manager
Tel: +31(0)513 78 8206
ADDRESS: Rivium Westlaan 142, 2909 LD
Capelle aan den IJssel, Netherlands


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[PATCH] MAINTAINERS: Move nvdimm mailing list

2021-04-21 Thread Dan Williams 
After seeing some users have subscription management trouble, more spam
than other Linux development lists, and considering some of the benefits
of kernel.org hosted lists, nvdimm and persistent memory development is
moving to nvd...@lists.linux.dev.

The old list will remain up until v5.14-rc1 and shutdown thereafter.

Cc: Ira Weiny 
Cc: Oliver O'Halloran 
Cc: Matthew Wilcox 
Cc: Jan Kara 
Cc: Jonathan Corbet 
Cc: Dave Jiang 
Cc: Vishal Verma 
Signed-off-by: Dan Williams 
---
 Documentation/ABI/obsolete/sysfs-class-dax|2 +
 Documentation/ABI/removed/sysfs-bus-nfit  |2 +
 Documentation/ABI/testing/sysfs-bus-nfit  |   40 +
 Documentation/ABI/testing/sysfs-bus-papr-pmem |4 +--
 Documentation/driver-api/nvdimm/nvdimm.rst|2 +
 MAINTAINERS   |   14 -
 6 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/Documentation/ABI/obsolete/sysfs-class-dax 
b/Documentation/ABI/obsolete/sysfs-class-dax
index 0faf1354cd05..5bcce27458e3 100644
--- a/Documentation/ABI/obsolete/sysfs-class-dax
+++ b/Documentation/ABI/obsolete/sysfs-class-dax
@@ -1,7 +1,7 @@
 What:   /sys/class/dax/
 Date:   May, 2016
 KernelVersion:  v4.7
-Contact:linux-nvdimm@lists.01.org
+Contact:nvd...@lists.linux.dev
 Description:   Device DAX is the device-centric analogue of Filesystem
DAX (CONFIG_FS_DAX).  It allows memory ranges to be
allocated and mapped without need of an intervening file
diff --git a/Documentation/ABI/removed/sysfs-bus-nfit 
b/Documentation/ABI/removed/sysfs-bus-nfit
index ae8c1ca53828..277437005def 100644
--- a/Documentation/ABI/removed/sysfs-bus-nfit
+++ b/Documentation/ABI/removed/sysfs-bus-nfit
@@ -1,7 +1,7 @@
 What:  /sys/bus/nd/devices/regionX/nfit/ecc_unit_size
 Date:  Aug, 2017
 KernelVersion: v4.14 (Removed v4.18)
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) Size of a write request to a DIMM that will not incur a
read-modify-write cycle at the memory controller.
diff --git a/Documentation/ABI/testing/sysfs-bus-nfit 
b/Documentation/ABI/testing/sysfs-bus-nfit
index 63ef0b9ecce7..e7282d184a74 100644
--- a/Documentation/ABI/testing/sysfs-bus-nfit
+++ b/Documentation/ABI/testing/sysfs-bus-nfit
@@ -5,7 +5,7 @@ Interface Table (NFIT)' section in the ACPI specification
 What:  /sys/bus/nd/devices/nmemX/nfit/serial
 Date:  Jun, 2015
 KernelVersion: v4.2
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) Serial number of the NVDIMM (non-volatile dual in-line
memory module), assigned by the module vendor.
@@ -14,7 +14,7 @@ Description:
 What:  /sys/bus/nd/devices/nmemX/nfit/handle
 Date:  Apr, 2015
 KernelVersion: v4.2
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) The address (given by the _ADR object) of the device on its
parent bus of the NVDIMM device containing the NVDIMM region.
@@ -23,7 +23,7 @@ Description:
 What:  /sys/bus/nd/devices/nmemX/nfit/device
 Date:  Apr, 2015
 KernelVersion: v4.1
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) Device id for the NVDIMM, assigned by the module vendor.
 
@@ -31,7 +31,7 @@ Description:
 What:  /sys/bus/nd/devices/nmemX/nfit/rev_id
 Date:  Jun, 2015
 KernelVersion: v4.2
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) Revision of the NVDIMM, assigned by the module vendor.
 
@@ -39,7 +39,7 @@ Description:
 What:  /sys/bus/nd/devices/nmemX/nfit/phys_id
 Date:  Apr, 2015
 KernelVersion: v4.2
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) Handle (i.e., instance number) for the SMBIOS (system
management BIOS) Memory Device structure describing the NVDIMM
@@ -49,7 +49,7 @@ Description:
 What:  /sys/bus/nd/devices/nmemX/nfit/flags
 Date:  Jun, 2015
 KernelVersion: v4.2
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) The flags in the NFIT memory device sub-structure indicate
the state of the data on the nvdimm relative to its energy
@@ -68,7 +68,7 @@ What: /sys/bus/nd/devices/nmemX/nfit/format1
 What:  /sys/bus/nd/devices/nmemX/nfit/formats
 Date:  Apr, 2016
 KernelVersion: v4.7
-Contact:   linux-nvdimm@lists.01.org
+Contact:   nvd...@lists.linux.dev
 Description:
(RO) The interface codes indicate support for persistent memory
mapped directly into system physical address space and / or a
@@ -84,7 +84,7 @@