From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Currently PageHWPoison flag does not behave well when experiencing memory
hotremove/hotplug. Any data field in struct page is unreliable when the
associated memory is offlined, and the current mechanism can't tell whether
a memory block is onlined because a new memory devices is installed or
because previous failed offline operations are undone. Especially if
there's a hwpoisoned memory, it's unclear what the best option is.
So introduce a new mechanism to make struct memory_block remember that
a memory block has hwpoisoned memory inside it. And make any online event
fail if the onlining memory block contains hwpoison. struct memory_block
is freed and reallocated over ACPI-based hotremove/hotplug, but not over
sysfs-based hotremove/hotplug. So the new counter can distinguish these
cases.
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: kernel test robot <lkp@intel.com>
---
ChangeLog v5 -> v6:
- fix build errors over memblk_nr_poison_inc() and memblk_nr_poison_sub(),
- pass "struct memory_block *" to memblk_nr_poison() instead of pfn,
- removed clear_hwpoisoned_pages() and call num_poisoned_pages_sub() directly.
- add static keyword to the definition of memblk_nr_poison().
- Mioahe added Reviewed-by for v5, but I have some non trivial changes in
v6, so let me hold to add it.
- unpoison_memory() properly cancels per-memblk hwpoison counter.
ChangeLog v4 -> v5:
- add Reported-by of lkp bot,
- check both CONFIG_MEMORY_FAILURE and CONFIG_MEMORY_HOTPLUG in introduced #ifdefs,
intending to fix "undefined reference" errors in aarch64.
ChangeLog v3 -> v4:
- fix build error (https://lore.kernel.org/linux-mm/202209231134.tnhKHRfg-lkp@intel.com/)
by using memblk_nr_poison() to access to the member ->nr_hwpoison
---
drivers/base/memory.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/linux/memory.h | 3 +++
include/linux/mm.h | 18 ++++++++++++++++++
mm/internal.h | 8 --------
mm/memory-failure.c | 36 +++++++++++-------------------------
mm/sparse.c | 2 --
6 files changed, 72 insertions(+), 35 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 9aa0da991cfb..5d00d8a14c79 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -175,6 +175,17 @@ int memory_notify(unsigned long val, void *v)
return blocking_notifier_call_chain(&memory_chain, val, v);
}
+#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
+void memblk_nr_poison_inc(unsigned long pfn);
+void memblk_nr_poison_sub(unsigned long pfn, long i);
+static unsigned long memblk_nr_poison(struct memory_block *mem);
+#else
+static inline unsigned long memblk_nr_poison(struct memory_block *mem)
+{
+ return 0;
+}
+#endif
+
static int memory_block_online(struct memory_block *mem)
{
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
@@ -183,6 +194,9 @@ static int memory_block_online(struct memory_block *mem)
struct zone *zone;
int ret;
+ if (memblk_nr_poison(mem))
+ return -EHWPOISON;
+
zone = zone_for_pfn_range(mem->online_type, mem->nid, mem->group,
start_pfn, nr_pages);
@@ -864,6 +878,7 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
+ num_poisoned_pages_sub(-1UL, memblk_nr_poison(mem));
unregister_memory_block_under_nodes(mem);
remove_memory_block(mem);
}
@@ -1164,3 +1179,28 @@ int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
}
return ret;
}
+
+#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
+void memblk_nr_poison_inc(unsigned long pfn)
+{
+ const unsigned long block_id = pfn_to_block_id(pfn);
+ struct memory_block *mem = find_memory_block_by_id(block_id);
+
+ if (mem)
+ atomic_long_inc(&mem->nr_hwpoison);
+}
+
+void memblk_nr_poison_sub(unsigned long pfn, long i)
+{
+ const unsigned long block_id = pfn_to_block_id(pfn);
+ struct memory_block *mem = find_memory_block_by_id(block_id);
+
+ if (mem)
+ atomic_long_sub(i, &mem->nr_hwpoison);
+}
+
+static unsigned long memblk_nr_poison(struct memory_block *mem)
+{
+ return atomic_long_read(&mem->nr_hwpoison);
+}
+#endif
diff --git a/include/linux/memory.h b/include/linux/memory.h
index aa619464a1df..ad8cd9bb3239 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -85,6 +85,9 @@ struct memory_block {
unsigned long nr_vmemmap_pages;
struct memory_group *group; /* group (if any) for this block */
struct list_head group_next; /* next block inside memory group */
+#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
+ atomic_long_t nr_hwpoison;
+#endif
};
int arch_get_memory_phys_device(unsigned long start_pfn);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 17119dbf8fad..f80269e90772 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3280,6 +3280,7 @@ extern int soft_offline_page(unsigned long pfn, int flags);
extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
bool *migratable_cleared);
extern void num_poisoned_pages_inc(unsigned long pfn);
+extern void num_poisoned_pages_sub(unsigned long pfn, long i);
#else
static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
bool *migratable_cleared)
@@ -3290,6 +3291,23 @@ static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
static inline void num_poisoned_pages_inc(unsigned long pfn)
{
}
+
+static inline void num_poisoned_pages_sub(unsigned long pfn, long i)
+{
+}
+#endif
+
+#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
+extern void memblk_nr_poison_inc(unsigned long pfn);
+extern void memblk_nr_poison_sub(unsigned long pfn, long i);
+#else
+static inline void memblk_nr_poison_inc(unsigned long pfn)
+{
+}
+
+static inline void memblk_nr_poison_sub(unsigned long pfn, long i)
+{
+}
#endif
#ifndef arch_memory_failure
diff --git a/mm/internal.h b/mm/internal.h
index b3002e03c28f..42ba8b96cab5 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -708,14 +708,6 @@ extern u64 hwpoison_filter_flags_value;
extern u64 hwpoison_filter_memcg;
extern u32 hwpoison_filter_enable;
-#ifdef CONFIG_MEMORY_FAILURE
-void clear_hwpoisoned_pages(struct page *memmap, int nr_pages);
-#else
-static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
-{
-}
-#endif
-
extern unsigned long __must_check vm_mmap_pgoff(struct file *, unsigned long,
unsigned long, unsigned long,
unsigned long, unsigned long);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index c19a301f16fc..4f5921590b76 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -77,11 +77,14 @@ static bool hw_memory_failure __read_mostly = false;
inline void num_poisoned_pages_inc(unsigned long pfn)
{
atomic_long_inc(&num_poisoned_pages);
+ memblk_nr_poison_inc(pfn);
}
-static inline void num_poisoned_pages_sub(unsigned long pfn, long i)
+inline void num_poisoned_pages_sub(unsigned long pfn, long i)
{
atomic_long_sub(i, &num_poisoned_pages);
+ if (pfn != -1UL)
+ memblk_nr_poison_sub(pfn, i);
}
/*
@@ -1706,6 +1709,8 @@ static unsigned long __free_raw_hwp_pages(struct page *hpage, bool move_flag)
if (move_flag)
SetPageHWPoison(p->page);
+ else
+ num_poisoned_pages_sub(page_to_pfn(p->page), 1);
kfree(p);
count++;
}
@@ -2337,6 +2342,7 @@ int unpoison_memory(unsigned long pfn)
int ret = -EBUSY;
int freeit = 0;
unsigned long count = 1;
+ bool huge = false;
static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
@@ -2385,6 +2391,7 @@ int unpoison_memory(unsigned long pfn)
ret = get_hwpoison_page(p, MF_UNPOISON);
if (!ret) {
if (PageHuge(p)) {
+ huge = true;
count = free_raw_hwp_pages(page, false);
if (count == 0) {
ret = -EBUSY;
@@ -2400,6 +2407,7 @@ int unpoison_memory(unsigned long pfn)
pfn, &unpoison_rs);
} else {
if (PageHuge(p)) {
+ huge = true;
count = free_raw_hwp_pages(page, false);
if (count == 0) {
ret = -EBUSY;
@@ -2419,7 +2427,8 @@ int unpoison_memory(unsigned long pfn)
unlock_mutex:
mutex_unlock(&mf_mutex);
if (!ret || freeit) {
- num_poisoned_pages_sub(pfn, count);
+ if (!huge)
+ num_poisoned_pages_sub(pfn, 1);
unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
page_to_pfn(p), &unpoison_rs);
}
@@ -2622,26 +2631,3 @@ int soft_offline_page(unsigned long pfn, int flags)
return ret;
}
-
-void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
-{
- int i, total = 0;
-
- /*
- * A further optimization is to have per section refcounted
- * num_poisoned_pages. But that would need more space per memmap, so
- * for now just do a quick global check to speed up this routine in the
- * absence of bad pages.
- */
- if (atomic_long_read(&num_poisoned_pages) == 0)
- return;
-
- for (i = 0; i < nr_pages; i++) {
- if (PageHWPoison(&memmap[i])) {
- total++;
- ClearPageHWPoison(&memmap[i]);
- }
- }
- if (total)
- num_poisoned_pages_sub(0, total);
-}
diff --git a/mm/sparse.c b/mm/sparse.c
index e5a8a3a0edd7..2779b419ef2a 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -926,8 +926,6 @@ void sparse_remove_section(struct mem_section *ms, unsigned long pfn,
unsigned long nr_pages, unsigned long map_offset,
struct vmem_altmap *altmap)
{
- clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset,
- nr_pages - map_offset);
section_deactivate(pfn, nr_pages, altmap);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
--
2.25.1On 2022/10/7 9:07, Naoya Horiguchi wrote:
> From: Naoya Horiguchi <naoya.horiguchi@nec.com>
>
> Currently PageHWPoison flag does not behave well when experiencing memory
> hotremove/hotplug. Any data field in struct page is unreliable when the
> associated memory is offlined, and the current mechanism can't tell whether
> a memory block is onlined because a new memory devices is installed or
> because previous failed offline operations are undone. Especially if
> there's a hwpoisoned memory, it's unclear what the best option is.
>
> So introduce a new mechanism to make struct memory_block remember that
> a memory block has hwpoisoned memory inside it. And make any online event
> fail if the onlining memory block contains hwpoison. struct memory_block
> is freed and reallocated over ACPI-based hotremove/hotplug, but not over
> sysfs-based hotremove/hotplug. So the new counter can distinguish these
> cases.
>
> Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
> Reported-by: kernel test robot <lkp@intel.com>
> ---
> ChangeLog v5 -> v6:
> - fix build errors over memblk_nr_poison_inc() and memblk_nr_poison_sub(),
> - pass "struct memory_block *" to memblk_nr_poison() instead of pfn,
> - removed clear_hwpoisoned_pages() and call num_poisoned_pages_sub() directly.
> - add static keyword to the definition of memblk_nr_poison().
> - Mioahe added Reviewed-by for v5, but I have some non trivial changes in
> v6, so let me hold to add it.
> - unpoison_memory() properly cancels per-memblk hwpoison counter.
>
> ChangeLog v4 -> v5:
> - add Reported-by of lkp bot,
> - check both CONFIG_MEMORY_FAILURE and CONFIG_MEMORY_HOTPLUG in introduced #ifdefs,
> intending to fix "undefined reference" errors in aarch64.
>
> ChangeLog v3 -> v4:
> - fix build error (https://lore.kernel.org/linux-mm/202209231134.tnhKHRfg-lkp@intel.com/)
> by using memblk_nr_poison() to access to the member ->nr_hwpoison
> ---
> drivers/base/memory.c | 40 ++++++++++++++++++++++++++++++++++++++++
> include/linux/memory.h | 3 +++
> include/linux/mm.h | 18 ++++++++++++++++++
> mm/internal.h | 8 --------
> mm/memory-failure.c | 36 +++++++++++-------------------------
> mm/sparse.c | 2 --
> 6 files changed, 72 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 9aa0da991cfb..5d00d8a14c79 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -175,6 +175,17 @@ int memory_notify(unsigned long val, void *v)
> return blocking_notifier_call_chain(&memory_chain, val, v);
> }
>
> +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
> +void memblk_nr_poison_inc(unsigned long pfn);
> +void memblk_nr_poison_sub(unsigned long pfn, long i);
> +static unsigned long memblk_nr_poison(struct memory_block *mem);
> +#else
> +static inline unsigned long memblk_nr_poison(struct memory_block *mem)
> +{
> + return 0;
> +}
> +#endif
> +
> static int memory_block_online(struct memory_block *mem)
> {
> unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
> @@ -183,6 +194,9 @@ static int memory_block_online(struct memory_block *mem)
> struct zone *zone;
> int ret;
>
> + if (memblk_nr_poison(mem))
> + return -EHWPOISON;
> +
> zone = zone_for_pfn_range(mem->online_type, mem->nid, mem->group,
> start_pfn, nr_pages);
>
> @@ -864,6 +878,7 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
> mem = find_memory_block_by_id(block_id);
> if (WARN_ON_ONCE(!mem))
> continue;
> + num_poisoned_pages_sub(-1UL, memblk_nr_poison(mem));
> unregister_memory_block_under_nodes(mem);
> remove_memory_block(mem);
> }
> @@ -1164,3 +1179,28 @@ int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func,
> }
> return ret;
> }
> +
> +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
> +void memblk_nr_poison_inc(unsigned long pfn)
> +{
> + const unsigned long block_id = pfn_to_block_id(pfn);
> + struct memory_block *mem = find_memory_block_by_id(block_id);
> +
> + if (mem)
> + atomic_long_inc(&mem->nr_hwpoison);
> +}
> +
> +void memblk_nr_poison_sub(unsigned long pfn, long i)
> +{
> + const unsigned long block_id = pfn_to_block_id(pfn);
> + struct memory_block *mem = find_memory_block_by_id(block_id);
> +
> + if (mem)
> + atomic_long_sub(i, &mem->nr_hwpoison);
> +}
> +
> +static unsigned long memblk_nr_poison(struct memory_block *mem)
> +{
> + return atomic_long_read(&mem->nr_hwpoison);
> +}
> +#endif
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index aa619464a1df..ad8cd9bb3239 100644
> --- a/include/linux/memory.h
> +++ b/include/linux/memory.h
> @@ -85,6 +85,9 @@ struct memory_block {
> unsigned long nr_vmemmap_pages;
> struct memory_group *group; /* group (if any) for this block */
> struct list_head group_next; /* next block inside memory group */
> +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
> + atomic_long_t nr_hwpoison;
> +#endif
> };
>
> int arch_get_memory_phys_device(unsigned long start_pfn);
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 17119dbf8fad..f80269e90772 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3280,6 +3280,7 @@ extern int soft_offline_page(unsigned long pfn, int flags);
> extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
> bool *migratable_cleared);
> extern void num_poisoned_pages_inc(unsigned long pfn);
> +extern void num_poisoned_pages_sub(unsigned long pfn, long i);
The prototype of this function is: *inline* void num_poisoned_pages_sub(unsigned long pfn, long i).
The combination of inline and extern looks weird to me. Is this a common use case?
Anyway, this patch looks good to me. Thanks.
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Thanks,
Miaohe Lin
On Sat, Oct 15, 2022 at 10:28:00AM +0800, Miaohe Lin wrote:
> On 2022/10/7 9:07, Naoya Horiguchi wrote:
...
> > diff --git a/include/linux/memory.h b/include/linux/memory.h
> > index aa619464a1df..ad8cd9bb3239 100644
> > --- a/include/linux/memory.h
> > +++ b/include/linux/memory.h
> > @@ -85,6 +85,9 @@ struct memory_block {
> > unsigned long nr_vmemmap_pages;
> > struct memory_group *group; /* group (if any) for this block */
> > struct list_head group_next; /* next block inside memory group */
> > +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
> > + atomic_long_t nr_hwpoison;
> > +#endif
> > };
> >
> > int arch_get_memory_phys_device(unsigned long start_pfn);
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 17119dbf8fad..f80269e90772 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -3280,6 +3280,7 @@ extern int soft_offline_page(unsigned long pfn, int flags);
> > extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
> > bool *migratable_cleared);
> > extern void num_poisoned_pages_inc(unsigned long pfn);
> > +extern void num_poisoned_pages_sub(unsigned long pfn, long i);
>
> The prototype of this function is: *inline* void num_poisoned_pages_sub(unsigned long pfn, long i).
> The combination of inline and extern looks weird to me. Is this a common use case?
No, it seems not. I can find a few place of such a comination like task_curr()
and raise_softirq_irqoff(), but as long as I understand, there's little meaning
(showing explicitly but redundant) to add extern keyword to functions in shared
header files. So I think of dropping the extern keyword.
>
> Anyway, this patch looks good to me. Thanks.
> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Thank you.
- Naoya Horiguchi
On 2022/10/17 19:43, HORIGUCHI NAOYA(堀口 直也) wrote:
> On Sat, Oct 15, 2022 at 10:28:00AM +0800, Miaohe Lin wrote:
>> On 2022/10/7 9:07, Naoya Horiguchi wrote:
> ...
>>> diff --git a/include/linux/memory.h b/include/linux/memory.h
>>> index aa619464a1df..ad8cd9bb3239 100644
>>> --- a/include/linux/memory.h
>>> +++ b/include/linux/memory.h
>>> @@ -85,6 +85,9 @@ struct memory_block {
>>> unsigned long nr_vmemmap_pages;
>>> struct memory_group *group; /* group (if any) for this block */
>>> struct list_head group_next; /* next block inside memory group */
>>> +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
>>> + atomic_long_t nr_hwpoison;
>>> +#endif
>>> };
>>>
>>> int arch_get_memory_phys_device(unsigned long start_pfn);
>>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>>> index 17119dbf8fad..f80269e90772 100644
>>> --- a/include/linux/mm.h
>>> +++ b/include/linux/mm.h
>>> @@ -3280,6 +3280,7 @@ extern int soft_offline_page(unsigned long pfn, int flags);
>>> extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
>>> bool *migratable_cleared);
>>> extern void num_poisoned_pages_inc(unsigned long pfn);
>>> +extern void num_poisoned_pages_sub(unsigned long pfn, long i);
>>
>> The prototype of this function is: *inline* void num_poisoned_pages_sub(unsigned long pfn, long i).
>> The combination of inline and extern looks weird to me. Is this a common use case?
>
> No, it seems not. I can find a few place of such a comination like task_curr()
> and raise_softirq_irqoff(), but as long as I understand, there's little meaning
> (showing explicitly but redundant) to add extern keyword to functions in shared
> header files. So I think of dropping the extern keyword.
That looks fine to me. My Reviewed-by tag still applies. Thanks Naoya.
Thanks,
Miaohe Lin
>
>>
>> Anyway, this patch looks good to me. Thanks.
>> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
>
> Thank you.
>
> - Naoya Horiguchi
>
On Fri, Oct 07, 2022 at 10:07:06AM +0900, Naoya Horiguchi wrote: > From: Naoya Horiguchi <naoya.horiguchi@nec.com> > > Currently PageHWPoison flag does not behave well when experiencing memory > hotremove/hotplug. Any data field in struct page is unreliable when the > associated memory is offlined, and the current mechanism can't tell whether > a memory block is onlined because a new memory devices is installed or > because previous failed offline operations are undone. Especially if > there's a hwpoisoned memory, it's unclear what the best option is. > > So introduce a new mechanism to make struct memory_block remember that > a memory block has hwpoisoned memory inside it. And make any online event > fail if the onlining memory block contains hwpoison. struct memory_block > is freed and reallocated over ACPI-based hotremove/hotplug, but not over > sysfs-based hotremove/hotplug. So the new counter can distinguish these > cases. > > Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> > Reported-by: kernel test robot <lkp@intel.com> I glanzed over it and looks good overall. Have a small question though: > @@ -864,6 +878,7 @@ void remove_memory_block_devices(unsigned long start, unsigned long size) > mem = find_memory_block_by_id(block_id); > if (WARN_ON_ONCE(!mem)) > continue; > + num_poisoned_pages_sub(-1UL, memblk_nr_poison(mem)); Why does num_poisoned_pages_sub() have to make this distinction (!-1 == -1) for the hot-remove stage? -- Oscar Salvador SUSE Labs
On Thu, Oct 13, 2022 at 10:33:45AM +0200, Oscar Salvador wrote: > On Fri, Oct 07, 2022 at 10:07:06AM +0900, Naoya Horiguchi wrote: > > From: Naoya Horiguchi <naoya.horiguchi@nec.com> > > > > Currently PageHWPoison flag does not behave well when experiencing memory > > hotremove/hotplug. Any data field in struct page is unreliable when the > > associated memory is offlined, and the current mechanism can't tell whether > > a memory block is onlined because a new memory devices is installed or > > because previous failed offline operations are undone. Especially if > > there's a hwpoisoned memory, it's unclear what the best option is. > > > > So introduce a new mechanism to make struct memory_block remember that > > a memory block has hwpoisoned memory inside it. And make any online event > > fail if the onlining memory block contains hwpoison. struct memory_block > > is freed and reallocated over ACPI-based hotremove/hotplug, but not over > > sysfs-based hotremove/hotplug. So the new counter can distinguish these > > cases. > > > > Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> > > Reported-by: kernel test robot <lkp@intel.com> > > I glanzed over it and looks good overall. > Have a small question though: Thank you for looking. > > > @@ -864,6 +878,7 @@ void remove_memory_block_devices(unsigned long start, unsigned long size) > > mem = find_memory_block_by_id(block_id); > > if (WARN_ON_ONCE(!mem)) > > continue; > > + num_poisoned_pages_sub(-1UL, memblk_nr_poison(mem)); > > Why does num_poisoned_pages_sub() have to make this distinction (!-1 == -1) > for the hot-remove stage? The first argument is used to find memory_block including the given pfn. And in the above context remove_memory_block_devices() already has the pointer "mem", so recalcurating it looked to me not necessary. Moreover, this code is about to free the memory_block so updating the counter inside it can be avoided. This is just a tiny optimization, and there can be better option. Thanks, Naoya Horiguchi
On Fri, Oct 07, 2022 at 10:07:06AM +0900, Naoya Horiguchi wrote: ... > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 9aa0da991cfb..5d00d8a14c79 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -175,6 +175,17 @@ int memory_notify(unsigned long val, void *v) > return blocking_notifier_call_chain(&memory_chain, val, v); > } > > +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) > +void memblk_nr_poison_inc(unsigned long pfn); > +void memblk_nr_poison_sub(unsigned long pfn, long i); Sorry again, these prototypes should not be necessary. I'll remove these when I need resubmit the patch series. It seems that scripts/checkpatch.pl shows the following warning by these. WARNING: externs should be avoided in .c files #59: FILE: drivers/base/memory.c:180: +void memblk_nr_poison_sub(unsigned long pfn, long i); This disappears by removing the prototypes. Thanks, Naoya Horiguchi
© 2016 - 2026 Red Hat, Inc.