+ mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch added to -mm tree

* + mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch added to -mm tree
@ 2022-02-17  3:02 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2022-02-17  3:02 UTC (permalink / raw)
  To: mm-commits, naoya.horiguchi, linmiaohe, akpm


The patch titled
     Subject: mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings()
has been added to the -mm tree.  Its filename is
     mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings()

Only for hugetlb pages in shared mappings, try_to_unmap should take
semaphore in write mode here.  Rework the code to make it clear.

Link: https://lkml.kernel.org/r/20220216091431.39406-7-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory-failure.c |   34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

--- a/mm/memory-failure.c~mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings
+++ a/mm/memory-failure.c
@@ -1404,26 +1404,22 @@ static bool hwpoison_user_mappings(struc
 	if (kill)
 		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
 
-	if (!PageHuge(hpage)) {
-		try_to_unmap(hpage, ttu);
+	if (PageHuge(hpage) && !PageAnon(hpage)) {
+		/*
+		 * For hugetlb pages in shared mappings, try_to_unmap
+		 * could potentially call huge_pmd_unshare.  Because of
+		 * this, take semaphore in write mode here and set
+		 * TTU_RMAP_LOCKED to indicate we have taken the lock
+		 * at this higher level.
+		 */
+		mapping = hugetlb_page_mapping_lock_write(hpage);
+		if (mapping) {
+			try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
+			i_mmap_unlock_write(mapping);
+		} else
+			pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
 	} else {
-		if (!PageAnon(hpage)) {
-			/*
-			 * For hugetlb pages in shared mappings, try_to_unmap
-			 * could potentially call huge_pmd_unshare.  Because of
-			 * this, take semaphore in write mode here and set
-			 * TTU_RMAP_LOCKED to indicate we have taken the lock
-			 * at this higher level.
-			 */
-			mapping = hugetlb_page_mapping_lock_write(hpage);
-			if (mapping) {
-				try_to_unmap(hpage, ttu|TTU_RMAP_LOCKED);
-				i_mmap_unlock_write(mapping);
-			} else
-				pr_info("Memory failure: %#lx: could not lock mapping for mapped huge page\n", pfn);
-		} else {
-			try_to_unmap(hpage, ttu);
-		}
+		try_to_unmap(hpage, ttu);
 	}
 
 	unmap_success = !page_mapped(hpage);
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-memremap-avoid-calling-kasan_remove_zero_shadow-for-device-private-memory.patch
filemap-remove-find_get_pages.patch
mm-sparse-make-mminit_validate_memmodel_limits-static.patch
mm-vmalloc-remove-unneeded-function-forward-declaration.patch
mm-mmzoneh-remove-unused-macros.patch
mm-memory-failurec-minor-clean-up-for-memory_failure_dev_pagemap.patch
mm-memory-failurec-catch-unexpected-efault-from-vma_address.patch
mm-memory-failurec-rework-the-signaling-logic-in-kill_proc.patch
mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch
mm-memory-failurec-remove-pageslab-check-in-hwpoison_filter_dev.patch
mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch
mm-memory-failurec-remove-obsolete-comment-in-__soft_offline_page.patch
mm-memory-failurec-remove-unnecessary-pagetranstail-check.patch
mm-balloon_compaction-make-balloon-page-compaction-callbacks-static.patch
mm-memory_hotplug-remove-obsolete-comment-of-__add_pages.patch
mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal.patch
mm-memory_hotplug-clean-up-try_offline_node.patch
mm-memory_hotplug-fix-misplaced-comment-in-offline_pages.patch
mm-highmem-remove-unnecessary-done-label.patch
mm-hmmc-remove-unneeded-local-variable-ret.patch


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