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

From: David Hildenbrand
Date: Wed Oct 16 2019 - 03:56:24 EST


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 <n-horiguchi@xxxxxxxxxxxxx>
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 <n-horiguchi@xxxxxxxxxxxxx>
---
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