2019-10-16 11:59:57

by Naoya Horiguchi

[permalink] [raw]
Subject: [PATCH] mm, soft-offline: convert parameter to pfn

Hi,

I wrote a simple cleanup for parameter of soft_offline_page(),
based on thread https://lkml.org/lkml/2019/10/11/57.

I know that we need more cleanup on hwpoison-inject, but I think
that will be mentioned in re-write patchset Oscar is preparing now.
So let me shared only this part as a separate one now.

Thanks,
Naoya Horiguchi
---
From: Naoya Horiguchi <[email protected]>
Date: Wed, 16 Oct 2019 15:49:00 +0900
Subject: [PATCH] mm, soft-offline: convert parameter to pfn

Currently soft_offline_page() receives struct page, and its sibling
memory_failure() receives pfn. This discrepancy looks weird and makes
precheck on pfn validity tricky. So let's align them.

Signed-off-by: Naoya Horiguchi <[email protected]>
---
drivers/base/memory.c | 2 +-
include/linux/mm.h | 2 +-
mm/madvise.c | 2 +-
mm/memory-failure.c | 8 ++++----
4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index e5485c22ef77..04e469c82852 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -540,7 +540,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
pfn >>= PAGE_SHIFT;
if (!pfn_valid(pfn))
return -ENXIO;
- ret = soft_offline_page(pfn_to_page(pfn));
+ ret = soft_offline_page(pfn);
return ret == 0 ? count : ret;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3eba26324ff1..0a452020edf5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2783,7 +2783,7 @@ extern int sysctl_memory_failure_early_kill;
extern int sysctl_memory_failure_recovery;
extern void shake_page(struct page *p, int access);
extern atomic_long_t num_poisoned_pages __read_mostly;
-extern int soft_offline_page(struct page *page);
+extern int soft_offline_page(unsigned long pfn);


/*
diff --git a/mm/madvise.c b/mm/madvise.c
index fd221b610b52..df198d1e5e2e 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -893,7 +893,7 @@ static int madvise_inject_error(int behavior,
if (behavior == MADV_SOFT_OFFLINE) {
pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
pfn, start);
- ret = soft_offline_page(page);
+ ret = soft_offline_page(pfn);
if (ret)
return ret;
} else {
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4f16e0a7e7cc..eb4fd5e8d5e1 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1514,7 +1514,7 @@ static void memory_failure_work_func(struct work_struct *work)
if (!gotten)
break;
if (entry.flags & MF_SOFT_OFFLINE)
- soft_offline_page(pfn_to_page(entry.pfn));
+ soft_offline_page(entry.pfn);
else
memory_failure(entry.pfn, entry.flags);
}
@@ -1822,7 +1822,7 @@ static int soft_offline_free_page(struct page *page)

/**
* soft_offline_page - Soft offline a page.
- * @page: page to offline
+ * @pfn: pfn to soft-offline
*
* Returns 0 on success, otherwise negated errno.
*
@@ -1841,10 +1841,10 @@ static int soft_offline_free_page(struct page *page)
* This is not a 100% solution for all memory, but tries to be
* ``good enough'' for the majority of memory.
*/
-int soft_offline_page(struct page *page)
+int soft_offline_page(unsigned long pfn)
{
int ret;
- unsigned long pfn = page_to_pfn(page);
+ struct page *page = pfn_to_page(pfn);

if (is_zone_device_page(page)) {
pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
--
2.17.1


2019-10-16 12:44:10

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On 16.10.19 09:09, Naoya Horiguchi wrote:
> Hi,
>
> I wrote a simple cleanup for parameter of soft_offline_page(),
> based on thread https://lkml.org/lkml/2019/10/11/57.
>
> I know that we need more cleanup on hwpoison-inject, but I think
> that will be mentioned in re-write patchset Oscar is preparing now.
> So let me shared only this part as a separate one now.
>
> Thanks,
> Naoya Horiguchi
> ---
> From: Naoya Horiguchi <[email protected]>
> Date: Wed, 16 Oct 2019 15:49:00 +0900
> Subject: [PATCH] mm, soft-offline: convert parameter to pfn
>
> Currently soft_offline_page() receives struct page, and its sibling
> memory_failure() receives pfn. This discrepancy looks weird and makes
> precheck on pfn validity tricky. So let's align them.
>
> Signed-off-by: Naoya Horiguchi <[email protected]>
> ---
> drivers/base/memory.c | 2 +-
> include/linux/mm.h | 2 +-
> mm/madvise.c | 2 +-
> mm/memory-failure.c | 8 ++++----
> 4 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index e5485c22ef77..04e469c82852 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -540,7 +540,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
> pfn >>= PAGE_SHIFT;
> if (!pfn_valid(pfn))
> return -ENXIO;
> - ret = soft_offline_page(pfn_to_page(pfn));
> + ret = soft_offline_page(pfn);
> return ret == 0 ? count : ret;
> }
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 3eba26324ff1..0a452020edf5 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2783,7 +2783,7 @@ extern int sysctl_memory_failure_early_kill;
> extern int sysctl_memory_failure_recovery;
> extern void shake_page(struct page *p, int access);
> extern atomic_long_t num_poisoned_pages __read_mostly;
> -extern int soft_offline_page(struct page *page);
> +extern int soft_offline_page(unsigned long pfn);
>
>
> /*
> diff --git a/mm/madvise.c b/mm/madvise.c
> index fd221b610b52..df198d1e5e2e 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -893,7 +893,7 @@ static int madvise_inject_error(int behavior,
> if (behavior == MADV_SOFT_OFFLINE) {
> pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
> pfn, start);
> - ret = soft_offline_page(page);
> + ret = soft_offline_page(pfn);
> if (ret)
> return ret;
> } else {
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 4f16e0a7e7cc..eb4fd5e8d5e1 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1514,7 +1514,7 @@ static void memory_failure_work_func(struct work_struct *work)
> if (!gotten)
> break;
> if (entry.flags & MF_SOFT_OFFLINE)
> - soft_offline_page(pfn_to_page(entry.pfn));
> + soft_offline_page(entry.pfn);
> else
> memory_failure(entry.pfn, entry.flags);
> }
> @@ -1822,7 +1822,7 @@ static int soft_offline_free_page(struct page *page)
>
> /**
> * soft_offline_page - Soft offline a page.
> - * @page: page to offline
> + * @pfn: pfn to soft-offline
> *
> * Returns 0 on success, otherwise negated errno.
> *
> @@ -1841,10 +1841,10 @@ static int soft_offline_free_page(struct page *page)
> * This is not a 100% solution for all memory, but tries to be
> * ``good enough'' for the majority of memory.
> */
> -int soft_offline_page(struct page *page)
> +int soft_offline_page(unsigned long pfn)
> {
> int ret;
> - unsigned long pfn = page_to_pfn(page);
> + struct page *page = pfn_to_page(pfn);
>
> if (is_zone_device_page(page)) {
> pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
>

I think you should rebase that patch on linux-next (where the
pfn_to_online_page() check is in place). I assume you'll want to move
the pfn_to_online_page() check into soft_offline_page() then as well?

--

Thanks,

David / dhildenb

2019-10-16 12:56:33

by Naoya Horiguchi

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
> On 16.10.19 09:09, Naoya Horiguchi wrote:
> > Hi,
> >
> > I wrote a simple cleanup for parameter of soft_offline_page(),
> > based on thread https://lkml.org/lkml/2019/10/11/57.
> >
> > I know that we need more cleanup on hwpoison-inject, but I think
> > that will be mentioned in re-write patchset Oscar is preparing now.
> > So let me shared only this part as a separate one now.
...
>
> I think you should rebase that patch on linux-next (where the
> pfn_to_online_page() check is in place). I assume you'll want to move the
> pfn_to_online_page() check into soft_offline_page() then as well?

I rebased to next-20191016. And yes, we will move pfn_to_online_page()
into soft offline code. It seems that we can also move pfn_valid(),
but is simply moving like below good enough for you?

@@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
* This is not a 100% solution for all memory, but tries to be
* ``good enough'' for the majority of memory.
*/
-int soft_offline_page(struct page *page, int flags)
+int soft_offline_page(unsigned long pfn, int flags)
{
int ret;
- unsigned long pfn = page_to_pfn(page);
+ struct page *page;

+ if (!pfn_valid(pfn))
+ return -ENXIO;
+ /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
+ if (!pfn_to_online_page(pfn))
+ return -EIO;
+ page = pfn_to_page(pfn);
if (is_zone_device_page(page)) {
pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
pfn);
--

Or we might have an option to do as memory_failure() does like below:

int memory_failure(unsigned long pfn, int flags)
{
....
p = pfn_to_online_page(pfn);
if (!p) {
if (pfn_valid(pfn)) {
pgmap = get_dev_pagemap(pfn, NULL);
if (pgmap)
return memory_failure_dev_pagemap(pfn, flags,
pgmap);
}
pr_err("Memory failure: %#lx: memory outside kernel control\n",
pfn);
return -ENXIO;
}

Thanks,
Naoya Horiguchi

2019-10-16 12:56:36

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On 16.10.19 10:27, Naoya Horiguchi wrote:
> On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
>> On 16.10.19 09:09, Naoya Horiguchi wrote:
>>> Hi,
>>>
>>> I wrote a simple cleanup for parameter of soft_offline_page(),
>>> based on thread https://lkml.org/lkml/2019/10/11/57.
>>>
>>> I know that we need more cleanup on hwpoison-inject, but I think
>>> that will be mentioned in re-write patchset Oscar is preparing now.
>>> So let me shared only this part as a separate one now.
> ...
>>
>> I think you should rebase that patch on linux-next (where the
>> pfn_to_online_page() check is in place). I assume you'll want to move the
>> pfn_to_online_page() check into soft_offline_page() then as well?
>
> I rebased to next-20191016. And yes, we will move pfn_to_online_page()
> into soft offline code. It seems that we can also move pfn_valid(),
> but is simply moving like below good enough for you?

At least I can't am the patch to current next/master (due to
pfn_to_online_page()).

>
> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> * This is not a 100% solution for all memory, but tries to be
> * ``good enough'' for the majority of memory.
> */
> -int soft_offline_page(struct page *page, int flags)
> +int soft_offline_page(unsigned long pfn, int flags)
> {
> int ret;
> - unsigned long pfn = page_to_pfn(page);
> + struct page *page;
>
> + if (!pfn_valid(pfn))
> + return -ENXIO;
> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> + if (!pfn_to_online_page(pfn))
> + return -EIO;
> + page = pfn_to_page(pfn);
> if (is_zone_device_page(page)) {
> pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
> pfn);
> --
>
> Or we might have an option to do as memory_failure() does like below:

In contrast to soft offlining, memory failure can deal with devmem. So I
think the above makes sense.

--

Thanks,

David / dhildenb

2019-10-16 13:17:57

by Naoya Horiguchi

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
> On 16.10.19 10:27, Naoya Horiguchi wrote:
> > On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
> > > On 16.10.19 09:09, Naoya Horiguchi wrote:
> > > > Hi,
> > > >
> > > > I wrote a simple cleanup for parameter of soft_offline_page(),
> > > > based on thread https://lkml.org/lkml/2019/10/11/57.
> > > >
> > > > I know that we need more cleanup on hwpoison-inject, but I think
> > > > that will be mentioned in re-write patchset Oscar is preparing now.
> > > > So let me shared only this part as a separate one now.
> > ...
> > >
> > > I think you should rebase that patch on linux-next (where the
> > > pfn_to_online_page() check is in place). I assume you'll want to move the
> > > pfn_to_online_page() check into soft_offline_page() then as well?
> >
> > I rebased to next-20191016. And yes, we will move pfn_to_online_page()
> > into soft offline code. It seems that we can also move pfn_valid(),
> > but is simply moving like below good enough for you?
>
> At least I can't am the patch to current next/master (due to
> pfn_to_online_page()).
>
> >
> > @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> > * This is not a 100% solution for all memory, but tries to be
> > * ``good enough'' for the majority of memory.
> > */
> > -int soft_offline_page(struct page *page, int flags)
> > +int soft_offline_page(unsigned long pfn, int flags)
> > {
> > int ret;
> > - unsigned long pfn = page_to_pfn(page);
> > + struct page *page;
> > + if (!pfn_valid(pfn))
> > + return -ENXIO;
> > + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> > + if (!pfn_to_online_page(pfn))
> > + return -EIO;
> > + page = pfn_to_page(pfn);
> > if (is_zone_device_page(page)) {
> > pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
> > pfn);
> > --
> >
> > Or we might have an option to do as memory_failure() does like below:
>
> In contrast to soft offlining, memory failure can deal with devmem. So I
> think the above makes sense.

OK, so here's the revised one.

Thanks,
Naoya Horiguchi
---
From: Naoya Horiguchi <[email protected]>
Date: Wed, 16 Oct 2019 17:00:33 +0900
Subject: [PATCH] mm, soft-offline: convert parameter to pfn

Currently soft_offline_page() receives struct page, and its sibling
memory_failure() receives pfn. This discrepancy looks weird and makes
precheck on pfn validity tricky. So let's align them.

Signed-off-by: Naoya Horiguchi <[email protected]>
---
drivers/base/memory.c | 7 +------
include/linux/mm.h | 2 +-
mm/madvise.c | 2 +-
mm/memory-failure.c | 14 ++++++++++----
4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 55907c27075b..a757d9ed88a7 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
- if (!pfn_valid(pfn))
- return -ENXIO;
- /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
- if (!pfn_to_online_page(pfn))
- return -EIO;
- ret = soft_offline_page(pfn_to_page(pfn), 0);
+ ret = soft_offline_page(pfn, 0);
return ret == 0 ? count : ret;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 44d058723db9..fd360d208346 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
extern int sysctl_memory_failure_recovery;
extern void shake_page(struct page *p, int access);
extern atomic_long_t num_poisoned_pages __read_mostly;
-extern int soft_offline_page(struct page *page, int flags);
+extern int soft_offline_page(unsigned long pfn, int flags);


/*
diff --git a/mm/madvise.c b/mm/madvise.c
index 2be9f3fdb05e..99dd06fecfa9 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
pfn, start);

- ret = soft_offline_page(page, MF_COUNT_INCREASED);
+ ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
if (ret)
return ret;
continue;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 05c8c6df25e6..bdf408d7f65c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
if (!gotten)
break;
if (entry.flags & MF_SOFT_OFFLINE)
- soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
+ soft_offline_page(entry.pfn, entry.flags);
else
memory_failure(entry.pfn, entry.flags);
}
@@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)

/**
* soft_offline_page - Soft offline a page.
- * @page: page to offline
+ * @pfn: pfn to soft-offline
* @flags: flags. Same as memory_failure().
*
* Returns 0 on success, otherwise negated errno.
@@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
* This is not a 100% solution for all memory, but tries to be
* ``good enough'' for the majority of memory.
*/
-int soft_offline_page(struct page *page, int flags)
+int soft_offline_page(unsigned long pfn, int flags)
{
int ret;
- unsigned long pfn = page_to_pfn(page);
+ struct page *page;

+ if (!pfn_valid(pfn))
+ return -ENXIO;
+ /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
+ page = pfn_to_online_page(pfn);
+ if (!page)
+ return -EIO;
if (is_zone_device_page(page)) {
pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
pfn);
--
2.17.1

2019-10-16 13:21:51

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On 16.10.19 10:54, Naoya Horiguchi wrote:
> On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
>> On 16.10.19 10:27, Naoya Horiguchi wrote:
>>> On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
>>>> On 16.10.19 09:09, Naoya Horiguchi wrote:
>>>>> Hi,
>>>>>
>>>>> I wrote a simple cleanup for parameter of soft_offline_page(),
>>>>> based on thread https://lkml.org/lkml/2019/10/11/57.
>>>>>
>>>>> I know that we need more cleanup on hwpoison-inject, but I think
>>>>> that will be mentioned in re-write patchset Oscar is preparing now.
>>>>> So let me shared only this part as a separate one now.
>>> ...
>>>>
>>>> I think you should rebase that patch on linux-next (where the
>>>> pfn_to_online_page() check is in place). I assume you'll want to move the
>>>> pfn_to_online_page() check into soft_offline_page() then as well?
>>>
>>> I rebased to next-20191016. And yes, we will move pfn_to_online_page()
>>> into soft offline code. It seems that we can also move pfn_valid(),
>>> but is simply moving like below good enough for you?
>>
>> At least I can't am the patch to current next/master (due to
>> pfn_to_online_page()).

Could also be that my "git am" skills failed as the mail was not a
proper patch itself :)

>>
>>>
>>> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
>>> * This is not a 100% solution for all memory, but tries to be
>>> * ``good enough'' for the majority of memory.
>>> */
>>> -int soft_offline_page(struct page *page, int flags)
>>> +int soft_offline_page(unsigned long pfn, int flags)
>>> {
>>> int ret;
>>> - unsigned long pfn = page_to_pfn(page);
>>> + struct page *page;
>>> + if (!pfn_valid(pfn))
>>> + return -ENXIO;
>>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
>>> + if (!pfn_to_online_page(pfn))
>>> + return -EIO;
>>> + page = pfn_to_page(pfn);
>>> if (is_zone_device_page(page)) {
>>> pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
>>> pfn);
>>> --
>>>
>>> Or we might have an option to do as memory_failure() does like below:
>>
>> In contrast to soft offlining, memory failure can deal with devmem. So I
>> think the above makes sense.
>
> OK, so here's the revised one.
>
> Thanks,
> Naoya Horiguchi
> ---
> From: Naoya Horiguchi <[email protected]>
> Date: Wed, 16 Oct 2019 17:00:33 +0900
> Subject: [PATCH] mm, soft-offline: convert parameter to pfn
>
> Currently soft_offline_page() receives struct page, and its sibling
> memory_failure() receives pfn. This discrepancy looks weird and makes
> precheck on pfn validity tricky. So let's align them.
>
> Signed-off-by: Naoya Horiguchi <[email protected]>
> ---
> drivers/base/memory.c | 7 +------
> include/linux/mm.h | 2 +-
> mm/madvise.c | 2 +-
> mm/memory-failure.c | 14 ++++++++++----
> 4 files changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 55907c27075b..a757d9ed88a7 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
> if (kstrtoull(buf, 0, &pfn) < 0)
> return -EINVAL;
> pfn >>= PAGE_SHIFT;
> - if (!pfn_valid(pfn))
> - return -ENXIO;
> - /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> - if (!pfn_to_online_page(pfn))
> - return -EIO;
> - ret = soft_offline_page(pfn_to_page(pfn), 0);
> + ret = soft_offline_page(pfn, 0);
> return ret == 0 ? count : ret;
> }
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 44d058723db9..fd360d208346 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
> extern int sysctl_memory_failure_recovery;
> extern void shake_page(struct page *p, int access);
> extern atomic_long_t num_poisoned_pages __read_mostly;
> -extern int soft_offline_page(struct page *page, int flags);
> +extern int soft_offline_page(unsigned long pfn, int flags);
>
>
> /*
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 2be9f3fdb05e..99dd06fecfa9 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
> pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
> pfn, start);
>
> - ret = soft_offline_page(page, MF_COUNT_INCREASED);
> + ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
> if (ret)
> return ret;
> continue;
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 05c8c6df25e6..bdf408d7f65c 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
> if (!gotten)
> break;
> if (entry.flags & MF_SOFT_OFFLINE)
> - soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
> + soft_offline_page(entry.pfn, entry.flags);
> else
> memory_failure(entry.pfn, entry.flags);
> }
> @@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)
>
> /**
> * soft_offline_page - Soft offline a page.
> - * @page: page to offline
> + * @pfn: pfn to soft-offline
> * @flags: flags. Same as memory_failure().
> *
> * Returns 0 on success, otherwise negated errno.
> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> * This is not a 100% solution for all memory, but tries to be
> * ``good enough'' for the majority of memory.
> */
> -int soft_offline_page(struct page *page, int flags)
> +int soft_offline_page(unsigned long pfn, int flags)
> {
> int ret;
> - unsigned long pfn = page_to_pfn(page);
> + struct page *page;
>
> + if (!pfn_valid(pfn))
> + return -ENXIO;
> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> + page = pfn_to_online_page(pfn);
> + if (!page)
> + return -EIO;
> if (is_zone_device_page(page)) {

-> this is now no longer possible! So you can drop the whole if
(is_zone_device....) case

> pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
> pfn);
>

Apart from that, looks good to me.

--

Thanks,

David / dhildenb

2019-10-18 05:17:53

by Naoya Horiguchi

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Wed, Oct 16, 2019 at 10:57:57AM +0200, David Hildenbrand wrote:
> On 16.10.19 10:54, Naoya Horiguchi wrote:
> >On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
> >>On 16.10.19 10:27, Naoya Horiguchi wrote:
> >>>On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
> >>>>On 16.10.19 09:09, Naoya Horiguchi wrote:
> >>>>>Hi,
> >>>>>
> >>>>>I wrote a simple cleanup for parameter of soft_offline_page(),
> >>>>>based on thread https://lkml.org/lkml/2019/10/11/57.
> >>>>>
> >>>>>I know that we need more cleanup on hwpoison-inject, but I think
> >>>>>that will be mentioned in re-write patchset Oscar is preparing now.
> >>>>>So let me shared only this part as a separate one now.
> >>>...
> >>>>
> >>>>I think you should rebase that patch on linux-next (where the
> >>>>pfn_to_online_page() check is in place). I assume you'll want to move the
> >>>>pfn_to_online_page() check into soft_offline_page() then as well?
> >>>
> >>>I rebased to next-20191016. And yes, we will move pfn_to_online_page()
> >>>into soft offline code. It seems that we can also move pfn_valid(),
> >>>but is simply moving like below good enough for you?
> >>
> >>At least I can't am the patch to current next/master (due to
> >>pfn_to_online_page()).
>
> Could also be that my "git am" skills failed as the mail was not a
> proper patch itself :)

Sorry for the inconvenience, my company email system breaks original
message by introducing quoted-printable format ('=20' or '=3D').
Most mail client usually handles it but git-am doesn't.
I give up using it and send via smtp.gmail.com.

> >@@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> > * This is not a 100% solution for all memory, but tries to be
> > * ``good enough'' for the majority of memory.
> > */
> >-int soft_offline_page(struct page *page, int flags)
> >+int soft_offline_page(unsigned long pfn, int flags)
> > {
> > int ret;
> >- unsigned long pfn = page_to_pfn(page);
> >+ struct page *page;
> >+ if (!pfn_valid(pfn))
> >+ return -ENXIO;
> >+ /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> >+ page = pfn_to_online_page(pfn);
> >+ if (!page)
> >+ return -EIO;
> > if (is_zone_device_page(page)) {
>
> -> this is now no longer possible! So you can drop the whole if
> (is_zone_device....) case

OK, thanks. I updated it.

Thanks,
Naoya Horiguchi
---
From 5faf227839b578726fe7f5ff414a153abb3b3a31 Mon Sep 17 00:00:00 2001
From: Naoya Horiguchi <[email protected]>
Date: Thu, 17 Oct 2019 08:40:53 +0900
Subject: [PATCH] mm, soft-offline: convert parameter to pfn

Currently soft_offline_page() receives struct page, and its sibling
memory_failure() receives pfn. This discrepancy looks weird and makes
precheck on pfn validity tricky. So let's align them.

Signed-off-by: Naoya Horiguchi <[email protected]>
---
drivers/base/memory.c | 7 +------
include/linux/mm.h | 2 +-
mm/madvise.c | 2 +-
mm/memory-failure.c | 19 +++++++++----------
4 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 55907c27075b..a757d9ed88a7 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
- if (!pfn_valid(pfn))
- return -ENXIO;
- /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
- if (!pfn_to_online_page(pfn))
- return -EIO;
- ret = soft_offline_page(pfn_to_page(pfn), 0);
+ ret = soft_offline_page(pfn, 0);
return ret == 0 ? count : ret;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 44d058723db9..fd360d208346 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
extern int sysctl_memory_failure_recovery;
extern void shake_page(struct page *p, int access);
extern atomic_long_t num_poisoned_pages __read_mostly;
-extern int soft_offline_page(struct page *page, int flags);
+extern int soft_offline_page(unsigned long pfn, int flags);


/*
diff --git a/mm/madvise.c b/mm/madvise.c
index 2be9f3fdb05e..99dd06fecfa9 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
pfn, start);

- ret = soft_offline_page(page, MF_COUNT_INCREASED);
+ ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
if (ret)
return ret;
continue;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 05c8c6df25e6..af2712004a4d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
if (!gotten)
break;
if (entry.flags & MF_SOFT_OFFLINE)
- soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
+ soft_offline_page(entry.pfn, entry.flags);
else
memory_failure(entry.pfn, entry.flags);
}
@@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)

/**
* soft_offline_page - Soft offline a page.
- * @page: page to offline
+ * @pfn: pfn to soft-offline
* @flags: flags. Same as memory_failure().
*
* Returns 0 on success, otherwise negated errno.
@@ -1877,18 +1877,17 @@ static int soft_offline_free_page(struct page *page)
* This is not a 100% solution for all memory, but tries to be
* ``good enough'' for the majority of memory.
*/
-int soft_offline_page(struct page *page, int flags)
+int soft_offline_page(unsigned long pfn, int flags)
{
int ret;
- unsigned long pfn = page_to_pfn(page);
+ struct page *page;

- if (is_zone_device_page(page)) {
- pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
- pfn);
- if (flags & MF_COUNT_INCREASED)
- put_page(page);
+ if (!pfn_valid(pfn))
+ return -ENXIO;
+ /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
+ page = pfn_to_online_page(pfn);
+ if (!page)
return -EIO;
- }

if (PageHWPoison(page)) {
pr_info("soft offline: %#lx page already poisoned\n", pfn);
--
2.17.1

2019-10-18 10:08:55

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On 17.10.19 01:47, Naoya Horiguchi wrote:
> On Wed, Oct 16, 2019 at 10:57:57AM +0200, David Hildenbrand wrote:
>> On 16.10.19 10:54, Naoya Horiguchi wrote:
>>> On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
>>>> On 16.10.19 10:27, Naoya Horiguchi wrote:
>>>>> On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
>>>>>> On 16.10.19 09:09, Naoya Horiguchi wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I wrote a simple cleanup for parameter of soft_offline_page(),
>>>>>>> based on thread https://lkml.org/lkml/2019/10/11/57.
>>>>>>>
>>>>>>> I know that we need more cleanup on hwpoison-inject, but I think
>>>>>>> that will be mentioned in re-write patchset Oscar is preparing now.
>>>>>>> So let me shared only this part as a separate one now.
>>>>> ...
>>>>>>
>>>>>> I think you should rebase that patch on linux-next (where the
>>>>>> pfn_to_online_page() check is in place). I assume you'll want to move the
>>>>>> pfn_to_online_page() check into soft_offline_page() then as well?
>>>>>
>>>>> I rebased to next-20191016. And yes, we will move pfn_to_online_page()
>>>>> into soft offline code. It seems that we can also move pfn_valid(),
>>>>> but is simply moving like below good enough for you?
>>>>
>>>> At least I can't am the patch to current next/master (due to
>>>> pfn_to_online_page()).
>>
>> Could also be that my "git am" skills failed as the mail was not a
>> proper patch itself :)
>
> Sorry for the inconvenience, my company email system breaks original
> message by introducing quoted-printable format ('=20' or '=3D').
> Most mail client usually handles it but git-am doesn't.
> I give up using it and send via smtp.gmail.com.
>
>>> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
>>> * This is not a 100% solution for all memory, but tries to be
>>> * ``good enough'' for the majority of memory.
>>> */
>>> -int soft_offline_page(struct page *page, int flags)
>>> +int soft_offline_page(unsigned long pfn, int flags)
>>> {
>>> int ret;
>>> - unsigned long pfn = page_to_pfn(page);
>>> + struct page *page;
>>> + if (!pfn_valid(pfn))
>>> + return -ENXIO;
>>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
>>> + page = pfn_to_online_page(pfn);
>>> + if (!page)
>>> + return -EIO;
>>> if (is_zone_device_page(page)) {
>>
>> -> this is now no longer possible! So you can drop the whole if
>> (is_zone_device....) case
>
> OK, thanks. I updated it.
>
> Thanks,
> Naoya Horiguchi
> ---
> From 5faf227839b578726fe7f5ff414a153abb3b3a31 Mon Sep 17 00:00:00 2001
> From: Naoya Horiguchi <[email protected]>
> Date: Thu, 17 Oct 2019 08:40:53 +0900
> Subject: [PATCH] mm, soft-offline: convert parameter to pfn
>
> Currently soft_offline_page() receives struct page, and its sibling
> memory_failure() receives pfn. This discrepancy looks weird and makes
> precheck on pfn validity tricky. So let's align them.
>
> Signed-off-by: Naoya Horiguchi <[email protected]>
> ---
> drivers/base/memory.c | 7 +------
> include/linux/mm.h | 2 +-
> mm/madvise.c | 2 +-
> mm/memory-failure.c | 19 +++++++++----------
> 4 files changed, 12 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 55907c27075b..a757d9ed88a7 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
> if (kstrtoull(buf, 0, &pfn) < 0)
> return -EINVAL;
> pfn >>= PAGE_SHIFT;
> - if (!pfn_valid(pfn))
> - return -ENXIO;
> - /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> - if (!pfn_to_online_page(pfn))
> - return -EIO;
> - ret = soft_offline_page(pfn_to_page(pfn), 0);
> + ret = soft_offline_page(pfn, 0);
> return ret == 0 ? count : ret;
> }
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 44d058723db9..fd360d208346 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
> extern int sysctl_memory_failure_recovery;
> extern void shake_page(struct page *p, int access);
> extern atomic_long_t num_poisoned_pages __read_mostly;
> -extern int soft_offline_page(struct page *page, int flags);
> +extern int soft_offline_page(unsigned long pfn, int flags);
>
>
> /*
> diff --git a/mm/madvise.c b/mm/madvise.c
> index 2be9f3fdb05e..99dd06fecfa9 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
> pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
> pfn, start);
>
> - ret = soft_offline_page(page, MF_COUNT_INCREASED);
> + ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
> if (ret)
> return ret;
> continue;
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 05c8c6df25e6..af2712004a4d 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
> if (!gotten)
> break;
> if (entry.flags & MF_SOFT_OFFLINE)
> - soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
> + soft_offline_page(entry.pfn, entry.flags);
> else
> memory_failure(entry.pfn, entry.flags);
> }
> @@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)
>
> /**
> * soft_offline_page - Soft offline a page.
> - * @page: page to offline
> + * @pfn: pfn to soft-offline
> * @flags: flags. Same as memory_failure().
> *
> * Returns 0 on success, otherwise negated errno.
> @@ -1877,18 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> * This is not a 100% solution for all memory, but tries to be
> * ``good enough'' for the majority of memory.
> */
> -int soft_offline_page(struct page *page, int flags)
> +int soft_offline_page(unsigned long pfn, int flags)
> {
> int ret;
> - unsigned long pfn = page_to_pfn(page);
> + struct page *page;
>
> - if (is_zone_device_page(page)) {
> - pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
> - pfn);
> - if (flags & MF_COUNT_INCREASED)
> - put_page(page);
> + if (!pfn_valid(pfn))
> + return -ENXIO;
> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> + page = pfn_to_online_page(pfn);
> + if (!page)

If you pass in a PFN with MF_COUNT_INCREASED via mm/madvise.c, you would
now no longer do a put_page(page) in case of ZONE_DEVICE (!page =
pfn_to_online_page(pfn);)

something like this

page = pfn_to_online_page(pfn);
if (!page) {
/*
* With MF_COUNT_INCREASED, we can use pfn_to_page() directly
* (esp., ZONE_DEVICE).
*/
if (flags & MF_COUNT_INCREASED)
put_page(pfn_to_page(page));
return -EIO;
}

For !pfn_valid(pfn), this is not relevant.

> return -EIO;
> - }
>
> if (PageHWPoison(page)) {
> pr_info("soft offline: %#lx page already poisoned\n", pfn);
>


--

Thanks,

David / dhildenb

2019-10-18 10:14:31

by Naoya Horiguchi

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Thu, Oct 17, 2019 at 09:16:42AM +0200, David Hildenbrand wrote:
> On 17.10.19 01:47, Naoya Horiguchi wrote:
> > On Wed, Oct 16, 2019 at 10:57:57AM +0200, David Hildenbrand wrote:
> > > On 16.10.19 10:54, Naoya Horiguchi wrote:
> > > > On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
> > > > > On 16.10.19 10:27, Naoya Horiguchi wrote:
> > > > > > On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
> > > > > > > On 16.10.19 09:09, Naoya Horiguchi wrote:
> > > > > > > > Hi,
> > > > > > > >
> > > > > > > > I wrote a simple cleanup for parameter of soft_offline_page(),
> > > > > > > > based on thread https://lkml.org/lkml/2019/10/11/57.
> > > > > > > >
> > > > > > > > I know that we need more cleanup on hwpoison-inject, but I think
> > > > > > > > that will be mentioned in re-write patchset Oscar is preparing now.
> > > > > > > > So let me shared only this part as a separate one now.
> > > > > > ...
> > > > > > >
> > > > > > > I think you should rebase that patch on linux-next (where the
> > > > > > > pfn_to_online_page() check is in place). I assume you'll want to move the
> > > > > > > pfn_to_online_page() check into soft_offline_page() then as well?
> > > > > >
> > > > > > I rebased to next-20191016. And yes, we will move pfn_to_online_page()
> > > > > > into soft offline code. It seems that we can also move pfn_valid(),
> > > > > > but is simply moving like below good enough for you?
> > > > >
> > > > > At least I can't am the patch to current next/master (due to
> > > > > pfn_to_online_page()).
> > >
> > > Could also be that my "git am" skills failed as the mail was not a
> > > proper patch itself :)
> >
> > Sorry for the inconvenience, my company email system breaks original
> > message by introducing quoted-printable format ('=20' or '=3D').
> > Most mail client usually handles it but git-am doesn't.
> > I give up using it and send via smtp.gmail.com.
> >
> > > > @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> > > > * This is not a 100% solution for all memory, but tries to be
> > > > * ``good enough'' for the majority of memory.
> > > > */
> > > > -int soft_offline_page(struct page *page, int flags)
> > > > +int soft_offline_page(unsigned long pfn, int flags)
> > > > {
> > > > int ret;
> > > > - unsigned long pfn = page_to_pfn(page);
> > > > + struct page *page;
> > > > + if (!pfn_valid(pfn))
> > > > + return -ENXIO;
> > > > + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> > > > + page = pfn_to_online_page(pfn);
> > > > + if (!page)
> > > > + return -EIO;
> > > > if (is_zone_device_page(page)) {
> > >
> > > -> this is now no longer possible! So you can drop the whole if
> > > (is_zone_device....) case
> >
> > OK, thanks. I updated it.
> >
> > Thanks,
> > Naoya Horiguchi
> > ---
> > From 5faf227839b578726fe7f5ff414a153abb3b3a31 Mon Sep 17 00:00:00 2001
> > From: Naoya Horiguchi <[email protected]>
> > Date: Thu, 17 Oct 2019 08:40:53 +0900
> > Subject: [PATCH] mm, soft-offline: convert parameter to pfn
> >
> > Currently soft_offline_page() receives struct page, and its sibling
> > memory_failure() receives pfn. This discrepancy looks weird and makes
> > precheck on pfn validity tricky. So let's align them.
> >
> > Signed-off-by: Naoya Horiguchi <[email protected]>
> > ---
> > drivers/base/memory.c | 7 +------
> > include/linux/mm.h | 2 +-
> > mm/madvise.c | 2 +-
> > mm/memory-failure.c | 19 +++++++++----------
> > 4 files changed, 12 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> > index 55907c27075b..a757d9ed88a7 100644
> > --- a/drivers/base/memory.c
> > +++ b/drivers/base/memory.c
> > @@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
> > if (kstrtoull(buf, 0, &pfn) < 0)
> > return -EINVAL;
> > pfn >>= PAGE_SHIFT;
> > - if (!pfn_valid(pfn))
> > - return -ENXIO;
> > - /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> > - if (!pfn_to_online_page(pfn))
> > - return -EIO;
> > - ret = soft_offline_page(pfn_to_page(pfn), 0);
> > + ret = soft_offline_page(pfn, 0);
> > return ret == 0 ? count : ret;
> > }
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 44d058723db9..fd360d208346 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
> > extern int sysctl_memory_failure_recovery;
> > extern void shake_page(struct page *p, int access);
> > extern atomic_long_t num_poisoned_pages __read_mostly;
> > -extern int soft_offline_page(struct page *page, int flags);
> > +extern int soft_offline_page(unsigned long pfn, int flags);
> > /*
> > diff --git a/mm/madvise.c b/mm/madvise.c
> > index 2be9f3fdb05e..99dd06fecfa9 100644
> > --- a/mm/madvise.c
> > +++ b/mm/madvise.c
> > @@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
> > pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
> > pfn, start);
> > - ret = soft_offline_page(page, MF_COUNT_INCREASED);
> > + ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
> > if (ret)
> > return ret;
> > continue;
> > diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> > index 05c8c6df25e6..af2712004a4d 100644
> > --- a/mm/memory-failure.c
> > +++ b/mm/memory-failure.c
> > @@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
> > if (!gotten)
> > break;
> > if (entry.flags & MF_SOFT_OFFLINE)
> > - soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
> > + soft_offline_page(entry.pfn, entry.flags);
> > else
> > memory_failure(entry.pfn, entry.flags);
> > }
> > @@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)
> > /**
> > * soft_offline_page - Soft offline a page.
> > - * @page: page to offline
> > + * @pfn: pfn to soft-offline
> > * @flags: flags. Same as memory_failure().
> > *
> > * Returns 0 on success, otherwise negated errno.
> > @@ -1877,18 +1877,17 @@ static int soft_offline_free_page(struct page *page)
> > * This is not a 100% solution for all memory, but tries to be
> > * ``good enough'' for the majority of memory.
> > */
> > -int soft_offline_page(struct page *page, int flags)
> > +int soft_offline_page(unsigned long pfn, int flags)
> > {
> > int ret;
> > - unsigned long pfn = page_to_pfn(page);
> > + struct page *page;
> > - if (is_zone_device_page(page)) {
> > - pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
> > - pfn);
> > - if (flags & MF_COUNT_INCREASED)
> > - put_page(page);
> > + if (!pfn_valid(pfn))
> > + return -ENXIO;
> > + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
> > + page = pfn_to_online_page(pfn);
> > + if (!page)
>
> If you pass in a PFN with MF_COUNT_INCREASED via mm/madvise.c, you would now
> no longer do a put_page(page) in case of ZONE_DEVICE (!page =
> pfn_to_online_page(pfn);)

Yes, right.

>
> something like this
>
> page = pfn_to_online_page(pfn);
> if (!page) {
> /*
> * With MF_COUNT_INCREASED, we can use pfn_to_page() directly
> * (esp., ZONE_DEVICE).
> */
> if (flags & MF_COUNT_INCREASED)
> put_page(pfn_to_page(page));
> return -EIO;
> }
>
> For !pfn_valid(pfn), this is not relevant.

Actually I guess that !pfn_valid() never happens when called from
madvise_inject_error(), because madvise_inject_error() gets pfn via
get_user_pages_fast() which only returns valid page for valid pfn.

And we plan to remove MF_COUNT_INCREASED by Oscar's re-design work,
so I start feeling that this patch should come on top of his tree.

Thanks,
Naoya Horiguchi

2019-10-18 10:14:45

by David Hildenbrand

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On 17.10.19 09:50, Naoya Horiguchi wrote:
> On Thu, Oct 17, 2019 at 09:16:42AM +0200, David Hildenbrand wrote:
>> On 17.10.19 01:47, Naoya Horiguchi wrote:
>>> On Wed, Oct 16, 2019 at 10:57:57AM +0200, David Hildenbrand wrote:
>>>> On 16.10.19 10:54, Naoya Horiguchi wrote:
>>>>> On Wed, Oct 16, 2019 at 10:34:52AM +0200, David Hildenbrand wrote:
>>>>>> On 16.10.19 10:27, Naoya Horiguchi wrote:
>>>>>>> On Wed, Oct 16, 2019 at 09:56:19AM +0200, David Hildenbrand wrote:
>>>>>>>> On 16.10.19 09:09, Naoya Horiguchi wrote:
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I wrote a simple cleanup for parameter of soft_offline_page(),
>>>>>>>>> based on thread https://lkml.org/lkml/2019/10/11/57.
>>>>>>>>>
>>>>>>>>> I know that we need more cleanup on hwpoison-inject, but I think
>>>>>>>>> that will be mentioned in re-write patchset Oscar is preparing now.
>>>>>>>>> So let me shared only this part as a separate one now.
>>>>>>> ...
>>>>>>>>
>>>>>>>> I think you should rebase that patch on linux-next (where the
>>>>>>>> pfn_to_online_page() check is in place). I assume you'll want to move the
>>>>>>>> pfn_to_online_page() check into soft_offline_page() then as well?
>>>>>>>
>>>>>>> I rebased to next-20191016. And yes, we will move pfn_to_online_page()
>>>>>>> into soft offline code. It seems that we can also move pfn_valid(),
>>>>>>> but is simply moving like below good enough for you?
>>>>>>
>>>>>> At least I can't am the patch to current next/master (due to
>>>>>> pfn_to_online_page()).
>>>>
>>>> Could also be that my "git am" skills failed as the mail was not a
>>>> proper patch itself :)
>>>
>>> Sorry for the inconvenience, my company email system breaks original
>>> message by introducing quoted-printable format ('=20' or '=3D').
>>> Most mail client usually handles it but git-am doesn't.
>>> I give up using it and send via smtp.gmail.com.
>>>
>>>>> @@ -1877,11 +1877,17 @@ static int soft_offline_free_page(struct page *page)
>>>>> * This is not a 100% solution for all memory, but tries to be
>>>>> * ``good enough'' for the majority of memory.
>>>>> */
>>>>> -int soft_offline_page(struct page *page, int flags)
>>>>> +int soft_offline_page(unsigned long pfn, int flags)
>>>>> {
>>>>> int ret;
>>>>> - unsigned long pfn = page_to_pfn(page);
>>>>> + struct page *page;
>>>>> + if (!pfn_valid(pfn))
>>>>> + return -ENXIO;
>>>>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
>>>>> + page = pfn_to_online_page(pfn);
>>>>> + if (!page)
>>>>> + return -EIO;
>>>>> if (is_zone_device_page(page)) {
>>>>
>>>> -> this is now no longer possible! So you can drop the whole if
>>>> (is_zone_device....) case
>>>
>>> OK, thanks. I updated it.
>>>
>>> Thanks,
>>> Naoya Horiguchi
>>> ---
>>> From 5faf227839b578726fe7f5ff414a153abb3b3a31 Mon Sep 17 00:00:00 2001
>>> From: Naoya Horiguchi <[email protected]>
>>> Date: Thu, 17 Oct 2019 08:40:53 +0900
>>> Subject: [PATCH] mm, soft-offline: convert parameter to pfn
>>>
>>> Currently soft_offline_page() receives struct page, and its sibling
>>> memory_failure() receives pfn. This discrepancy looks weird and makes
>>> precheck on pfn validity tricky. So let's align them.
>>>
>>> Signed-off-by: Naoya Horiguchi <[email protected]>
>>> ---
>>> drivers/base/memory.c | 7 +------
>>> include/linux/mm.h | 2 +-
>>> mm/madvise.c | 2 +-
>>> mm/memory-failure.c | 19 +++++++++----------
>>> 4 files changed, 12 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>>> index 55907c27075b..a757d9ed88a7 100644
>>> --- a/drivers/base/memory.c
>>> +++ b/drivers/base/memory.c
>>> @@ -538,12 +538,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
>>> if (kstrtoull(buf, 0, &pfn) < 0)
>>> return -EINVAL;
>>> pfn >>= PAGE_SHIFT;
>>> - if (!pfn_valid(pfn))
>>> - return -ENXIO;
>>> - /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
>>> - if (!pfn_to_online_page(pfn))
>>> - return -EIO;
>>> - ret = soft_offline_page(pfn_to_page(pfn), 0);
>>> + ret = soft_offline_page(pfn, 0);
>>> return ret == 0 ? count : ret;
>>> }
>>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>>> index 44d058723db9..fd360d208346 100644
>>> --- a/include/linux/mm.h
>>> +++ b/include/linux/mm.h
>>> @@ -2794,7 +2794,7 @@ extern int sysctl_memory_failure_early_kill;
>>> extern int sysctl_memory_failure_recovery;
>>> extern void shake_page(struct page *p, int access);
>>> extern atomic_long_t num_poisoned_pages __read_mostly;
>>> -extern int soft_offline_page(struct page *page, int flags);
>>> +extern int soft_offline_page(unsigned long pfn, int flags);
>>> /*
>>> diff --git a/mm/madvise.c b/mm/madvise.c
>>> index 2be9f3fdb05e..99dd06fecfa9 100644
>>> --- a/mm/madvise.c
>>> +++ b/mm/madvise.c
>>> @@ -887,7 +887,7 @@ static int madvise_inject_error(int behavior,
>>> pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
>>> pfn, start);
>>> - ret = soft_offline_page(page, MF_COUNT_INCREASED);
>>> + ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
>>> if (ret)
>>> return ret;
>>> continue;
>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>>> index 05c8c6df25e6..af2712004a4d 100644
>>> --- a/mm/memory-failure.c
>>> +++ b/mm/memory-failure.c
>>> @@ -1476,7 +1476,7 @@ static void memory_failure_work_func(struct work_struct *work)
>>> if (!gotten)
>>> break;
>>> if (entry.flags & MF_SOFT_OFFLINE)
>>> - soft_offline_page(pfn_to_page(entry.pfn), entry.flags);
>>> + soft_offline_page(entry.pfn, entry.flags);
>>> else
>>> memory_failure(entry.pfn, entry.flags);
>>> }
>>> @@ -1857,7 +1857,7 @@ static int soft_offline_free_page(struct page *page)
>>> /**
>>> * soft_offline_page - Soft offline a page.
>>> - * @page: page to offline
>>> + * @pfn: pfn to soft-offline
>>> * @flags: flags. Same as memory_failure().
>>> *
>>> * Returns 0 on success, otherwise negated errno.
>>> @@ -1877,18 +1877,17 @@ static int soft_offline_free_page(struct page *page)
>>> * This is not a 100% solution for all memory, but tries to be
>>> * ``good enough'' for the majority of memory.
>>> */
>>> -int soft_offline_page(struct page *page, int flags)
>>> +int soft_offline_page(unsigned long pfn, int flags)
>>> {
>>> int ret;
>>> - unsigned long pfn = page_to_pfn(page);
>>> + struct page *page;
>>> - if (is_zone_device_page(page)) {
>>> - pr_debug_ratelimited("soft_offline: %#lx page is device page\n",
>>> - pfn);
>>> - if (flags & MF_COUNT_INCREASED)
>>> - put_page(page);
>>> + if (!pfn_valid(pfn))
>>> + return -ENXIO;
>>> + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
>>> + page = pfn_to_online_page(pfn);
>>> + if (!page)
>>
>> If you pass in a PFN with MF_COUNT_INCREASED via mm/madvise.c, you would now
>> no longer do a put_page(page) in case of ZONE_DEVICE (!page =
>> pfn_to_online_page(pfn);)
>
> Yes, right.
>
>>
>> something like this
>>
>> page = pfn_to_online_page(pfn);
>> if (!page) {
>> /*
>> * With MF_COUNT_INCREASED, we can use pfn_to_page() directly
>> * (esp., ZONE_DEVICE).
>> */
>> if (flags & MF_COUNT_INCREASED)
>> put_page(pfn_to_page(page));
>> return -EIO;
>> }
>>
>> For !pfn_valid(pfn), this is not relevant.
>
> Actually I guess that !pfn_valid() never happens when called from
> madvise_inject_error(), because madvise_inject_error() gets pfn via
> get_user_pages_fast() which only returns valid page for valid pfn.
>
> And we plan to remove MF_COUNT_INCREASED by Oscar's re-design work,
> so I start feeling that this patch should come on top of his tree.

I agree, let's clean that up first.

--

Thanks,

David / dhildenb

2019-10-18 10:14:47

by Oscar Salvador

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Thu, Oct 17, 2019 at 07:50:18AM +0000, Naoya Horiguchi wrote:
> Actually I guess that !pfn_valid() never happens when called from
> madvise_inject_error(), because madvise_inject_error() gets pfn via
> get_user_pages_fast() which only returns valid page for valid pfn.
>
> And we plan to remove MF_COUNT_INCREASED by Oscar's re-design work,
> so I start feeling that this patch should come on top of his tree.

Hi Naoya,

I am pretty much done with my testing.
If you feel like, I can take the patch and add it on top of [1]
, then I will do some more testing and, if nothing pops up, I will
send it upstream.

[1] https://github.com/leberus/linux/tree/hwpoison-v2

>
> Thanks,
> Naoya Horiguchi

--
Oscar Salvador
SUSE L3

2019-10-18 10:15:10

by Naoya Horiguchi

[permalink] [raw]
Subject: Re: [PATCH] mm, soft-offline: convert parameter to pfn

On Thu, Oct 17, 2019 at 10:03:21AM +0200, Oscar Salvador wrote:
> On Thu, Oct 17, 2019 at 07:50:18AM +0000, Naoya Horiguchi wrote:
> > Actually I guess that !pfn_valid() never happens when called from
> > madvise_inject_error(), because madvise_inject_error() gets pfn via
> > get_user_pages_fast() which only returns valid page for valid pfn.
> >
> > And we plan to remove MF_COUNT_INCREASED by Oscar's re-design work,
> > so I start feeling that this patch should come on top of his tree.
>
> Hi Naoya,
>
> I am pretty much done with my testing.
> If you feel like, I can take the patch and add it on top of [1]
> , then I will do some more testing and, if nothing pops up, I will
> send it upstream.

Hi Oscar,
Yes, please take it, thank you for speaking up.

>
> [1] https://github.com/leberus/linux/tree/hwpoison-v2