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authorRick Edgecombe <rick.p.edgecombe@intel.com>2019-04-25 17:11:35 -0700
committerIngo Molnar <mingo@kernel.org>2019-04-30 12:37:57 +0200
commitd63326928611600ad65baff54a70f53b02b3cdfe (patch)
tree65cd76b106b5b15272b1960ca2ba600f9ff21571 /kernel/power
parentd253ca0c3865a8d9a8c01143cf20425e0be4d0ce (diff)
mm/hibernation: Make hibernation handle unmapped pages
Make hibernate handle unmapped pages on the direct map when CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages to invalid configurations, so now hibernate should check if the pages have valid mappings and handle if they are unmapped when doing a hibernate save operation. Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y was configured. It does not appear to have a big hibernating performance impact. The speed of the saving operation before this change was measured as 819.02 MB/s, and after was measured at 813.32 MB/s. Before: [ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s) After: [ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s) Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-16-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/snapshot.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index f08a1e4ee1d4..bc9558ab1e5b 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1342,8 +1342,9 @@ static inline void do_copy_page(long *dst, long *src)
* safe_copy_page - Copy a page in a safe way.
*
* Check if the page we are going to copy is marked as present in the kernel
- * page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set
- * and in that case kernel_page_present() always returns 'true').
+ * page tables. This always is the case if CONFIG_DEBUG_PAGEALLOC or
+ * CONFIG_ARCH_HAS_SET_DIRECT_MAP is not set. In that case kernel_page_present()
+ * always returns 'true'.
*/
static void safe_copy_page(void *dst, struct page *s_page)
{