[PATCH v4 3/4] mm: Mark pages allocated through vmalloc
From: Matthew Wilcox <willy@infradead.org>
Date: 2018-03-01 21:16:01
Also in:
linux-mm, lkml
Subsystem:
filesystems (vfs and infrastructure), memory management, proc filesystem, the rest, vmalloc · Maintainers:
Alexander Viro, Christian Brauner, Andrew Morton, Linus Torvalds, Uladzislau Rezki
From: Matthew Wilcox <redacted> Use a bit in page_type to mark pages which have been allocated through vmalloc. This can be helpful when debugging crashdumps or analysing memory fragmentation. Add a KPF flag to report these pages to userspace and update page-types.c to interpret that flag. Signed-off-by: Matthew Wilcox <redacted> --- fs/proc/page.c | 2 ++ include/linux/page-flags.h | 6 ++++++ include/uapi/linux/kernel-page-flags.h | 2 +- mm/vmalloc.c | 2 ++ tools/vm/page-types.c | 1 + 5 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 1491918a33c3..c9757af919a3 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c@@ -154,6 +154,8 @@ u64 stable_page_flags(struct page *page) if (PageBalloon(page)) u |= 1 << KPF_BALLOON; + if (PageVmalloc(page)) + u |= 1 << KPF_VMALLOC; if (page_is_idle(page)) u |= 1 << KPF_IDLE;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index d151f590bbc6..8142ab716e90 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h@@ -643,6 +643,7 @@ PAGEFLAG_FALSE(DoubleMap) #define PG_buddy 0x00000080 #define PG_balloon 0x00000100 #define PG_kmemcg 0x00000200 +#define PG_vmalloc 0x00000400 #define PageType(page, flag) \ ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
@@ -681,6 +682,11 @@ PAGE_TYPE_OPS(Balloon, balloon) */ PAGE_TYPE_OPS(Kmemcg, kmemcg) +/* + * Pages allocated through vmalloc are tagged with this bit. + */ +PAGE_TYPE_OPS(Vmalloc, vmalloc) + extern bool is_free_buddy_page(struct page *page); __PAGEFLAG(Isolated, isolated, PF_ANY);
diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h
index fa139841ec18..5f1735ff05b3 100644
--- a/include/uapi/linux/kernel-page-flags.h
+++ b/include/uapi/linux/kernel-page-flags.h@@ -35,6 +35,6 @@ #define KPF_BALLOON 23 #define KPF_ZERO_PAGE 24 #define KPF_IDLE 25 - +#define KPF_VMALLOC 26 #endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ebff729cc956..3bc0538fc21b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c@@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); + __ClearPageVmalloc(page); __free_pages(page, 0); }
@@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, area->nr_pages = i; goto fail; } + __SetPageVmalloc(page); area->pages[i] = page; if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) cond_resched();
diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index a8783f48f77f..116f59eff5e2 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c@@ -131,6 +131,7 @@ static const char * const page_flag_names[] = { [KPF_KSM] = "x:ksm", [KPF_THP] = "t:thp", [KPF_BALLOON] = "o:balloon", + [KPF_VMALLOC] = "V:vmalloc", [KPF_ZERO_PAGE] = "z:zero_page", [KPF_IDLE] = "i:idle_page",
--
2.16.1