From: Zi Yan <[email protected]> This prepares for THP migration support. During soft-offlining, if a THP is migrated without splitting, we need to soft-offline pages after the THP. Otherwise, we need to soft-offline the next subpage in that THP.
The new added output parameter in soft_offline_page() help distinguish the two conditions above. As THPs are split after they are free, we cannot distinguish the two conditions by examining the soft-offlined pages. Signed-off-by: Zi Yan <[email protected]> --- drivers/base/memory.c | 2 +- include/linux/mm.h | 2 +- mm/madvise.c | 9 +++++---- mm/memory-failure.c | 11 +++++++---- 4 files changed, 14 insertions(+), 10 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 4e3b61cda520..3ab25b05d5e8 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -551,7 +551,7 @@ store_soft_offline_page(struct device *dev, pfn >>= PAGE_SHIFT; if (!pfn_valid(pfn)) return -ENXIO; - ret = soft_offline_page(pfn_to_page(pfn), 0); + ret = soft_offline_page(pfn_to_page(pfn), 0, NULL); return ret == 0 ? count : ret; } diff --git a/include/linux/mm.h b/include/linux/mm.h index 6f543a47fc92..d392fa090ab5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2467,7 +2467,7 @@ 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; -extern int soft_offline_page(struct page *page, int flags); +extern int soft_offline_page(struct page *page, int flags, int *split); /* diff --git a/mm/madvise.c b/mm/madvise.c index 49f6774db259..857255db404a 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -634,17 +634,18 @@ static int madvise_inject_error(int behavior, } if (behavior == MADV_SOFT_OFFLINE) { + int split = 0; + pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n", page_to_pfn(page), start); - ret = soft_offline_page(page, MF_COUNT_INCREASED); + ret = soft_offline_page(page, MF_COUNT_INCREASED, &split); if (ret) return ret; /* - * Non hugetlb pages either have PAGE_SIZE - * or are split into PAGE_SIZE + * If the page is split, page_size should be changed. */ - if (!PageHuge(page)) + if (split) page_size = PAGE_SIZE; continue; } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 8b8ff29412b6..8a9ac6f9e1b0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1361,7 +1361,7 @@ 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(pfn_to_page(entry.pfn), entry.flags, NULL); else memory_failure(entry.pfn, entry.trapno, entry.flags); } @@ -1678,7 +1678,7 @@ static int __soft_offline_page(struct page *page, int flags) return ret; } -static int soft_offline_in_use_page(struct page *page, int flags) +static int soft_offline_in_use_page(struct page *page, int flags, int *split) { int ret; struct page *hpage = compound_head(page); @@ -1694,6 +1694,8 @@ static int soft_offline_in_use_page(struct page *page, int flags) put_hwpoison_page(hpage); return -EBUSY; } + if (split) + *split = 1; unlock_page(hpage); get_hwpoison_page(page); put_hwpoison_page(hpage); @@ -1722,6 +1724,7 @@ static void soft_offline_free_page(struct page *page) * soft_offline_page - Soft offline a page. * @page: page to offline * @flags: flags. Same as memory_failure(). + * @split: output. Tells if page is split or not. * * Returns 0 on success, otherwise negated errno. * @@ -1740,7 +1743,7 @@ static void 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(struct page *page, int flags, int *split) { int ret; unsigned long pfn = page_to_pfn(page); @@ -1757,7 +1760,7 @@ int soft_offline_page(struct page *page, int flags) put_online_mems(); if (ret > 0) - ret = soft_offline_in_use_page(page, flags); + ret = soft_offline_in_use_page(page, flags, split); else if (ret == 0) soft_offline_free_page(page); -- 2.13.2
