Pick up a mm fix causing hangs (rhbz 1693525)

2 files changed, 116 insertions, 0 deletions

diff --git a/Correct-zone-boundary-handling-when-resetting-pageblock-skip-hints.patch b/Correct-zone-boundary-handling-when-resetting-pageblock-skip-hints.patch
new file mode 100644
index 000000000..c0eb9bcab
--- /dev/null
+++ b/Correct-zone-boundary-handling-when-resetting-pageblock-skip-hints.patch
@@ -0,0 +1,113 @@
+From patchwork Wed Mar 27 08:54:24 2019
+Date: Wed, 27 Mar 2019 08:54:24 +0000
+From: Mel Gorman <mgorman@techsingularity.net>
+To: Andrew Morton <akpm@linux-foundation.org>
+Cc: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>,
+	Daniel Jordan <daniel.m.jordan@oracle.com>, Qian Cai <cai@lca.pw>,
+	linux-mm@kvack.org, vbabka@suse.cz, linux-kernel@vger.kernel.org
+Subject: [PATCH] Correct zone boundary handling when resetting pageblock skip
+ hints
+
+Mikhail Gavrilo reported the following bug being triggered in a Fedora
+kernel based on 5.1-rc1 but it is relevant to a vanilla kernel.
+
+ kernel: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
+ kernel: ------------[ cut here ]------------
+ kernel: kernel BUG at include/linux/mm.h:1021!
+ kernel: invalid opcode: 0000 [#1] SMP NOPTI
+ kernel: CPU: 6 PID: 116 Comm: kswapd0 Tainted: G         C        5.1.0-0.rc1.git1.3.fc31.x86_64 #1
+ kernel: Hardware name: System manufacturer System Product Name/ROG STRIX X470-I GAMING, BIOS 1201 12/07/2018
+ kernel: RIP: 0010:__reset_isolation_pfn+0x244/0x2b0
+ kernel: Code: fe 06 e8 0f 8e fc ff 44 0f b6 4c 24 04 48 85 c0 0f 85 dc fe ff ff e9 68 fe ff ff 48 c7 c6 58 b7 2e 8c 4c 89 ff e8 0c 75 00 00 <0f> 0b 48 c7 c6 58 b7 2e 8c e8 fe 74 00 00 0f 0b 48 89 fa 41 b8 01
+ kernel: RSP: 0018:ffff9e2d03f0fde8 EFLAGS: 00010246
+ kernel: RAX: 0000000000000034 RBX: 000000000081f380 RCX: ffff8cffbddd6c20
+ kernel: RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff8cffbddd6c20
+ kernel: RBP: 0000000000000001 R08: 0000009898b94613 R09: 0000000000000000
+ kernel: R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000100000
+ kernel: R13: 0000000000100000 R14: 0000000000000001 R15: ffffca7de07ce000
+ kernel: FS:  0000000000000000(0000) GS:ffff8cffbdc00000(0000) knlGS:0000000000000000
+ kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+ kernel: CR2: 00007fc1670e9000 CR3: 00000007f5276000 CR4: 00000000003406e0
+ kernel: Call Trace:
+ kernel:  __reset_isolation_suitable+0x62/0x120
+ kernel:  reset_isolation_suitable+0x3b/0x40
+ kernel:  kswapd+0x147/0x540
+ kernel:  ? finish_wait+0x90/0x90
+ kernel:  kthread+0x108/0x140
+ kernel:  ? balance_pgdat+0x560/0x560
+ kernel:  ? kthread_park+0x90/0x90
+ kernel:  ret_from_fork+0x27/0x50
+
+He bisected it down to commit e332f741a8dd ("mm, compaction: be selective
+about what pageblocks to clear skip hints"). The problem is that the patch
+in question was sloppy with respect to the handling of zone boundaries. In
+some instances, it was possible for PFNs outside of a zone to be examined
+and if those were not properly initialised or poisoned then it would
+trigger the VM_BUG_ON. This patch corrects the zone boundary issues when
+resetting pageblock skip hints and Mikhail reported that the bug did not
+trigger after 30 hours of testing.
+
+Fixes: e332f741a8dd ("mm, compaction: be selective about what pageblocks to clear skip hints")
+Reported-and-tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
+Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
+---
+ mm/compaction.c | 27 +++++++++++++++++----------
+ 1 file changed, 17 insertions(+), 10 deletions(-)
+
+diff --git a/mm/compaction.c b/mm/compaction.c
+index f171a83707ce..b4930bf93c8a 100644
+--- a/mm/compaction.c
++++ b/mm/compaction.c
+@@ -242,6 +242,7 @@ __reset_isolation_pfn(struct zone *zone, unsigned long pfn, bool check_source,
+ 							bool check_target)
+ {
+ 	struct page *page = pfn_to_online_page(pfn);
++	struct page *block_page;
+ 	struct page *end_page;
+ 	unsigned long block_pfn;
+ 
+@@ -267,20 +268,26 @@ __reset_isolation_pfn(struct zone *zone, unsigned long pfn, bool check_source,
+ 	    get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
+ 		return false;
+ 
++	/* Ensure the start of the pageblock or zone is online and valid */
++	block_pfn = pageblock_start_pfn(pfn);
++	block_page = pfn_to_online_page(max(block_pfn, zone->zone_start_pfn));
++	if (block_page) {
++		page = block_page;
++		pfn = block_pfn;
++	}
++
++	/* Ensure the end of the pageblock or zone is online and valid */
++	block_pfn += pageblock_nr_pages;
++	block_pfn = min(block_pfn, zone_end_pfn(zone) - 1);
++	end_page = pfn_to_online_page(block_pfn);
++	if (!end_page)
++		return false;
++
+ 	/*
+ 	 * Only clear the hint if a sample indicates there is either a
+ 	 * free page or an LRU page in the block. One or other condition
+ 	 * is necessary for the block to be a migration source/target.
+ 	 */
+-	block_pfn = pageblock_start_pfn(pfn);
+-	pfn = max(block_pfn, zone->zone_start_pfn);
+-	page = pfn_to_page(pfn);
+-	if (zone != page_zone(page))
+-		return false;
+-	pfn = block_pfn + pageblock_nr_pages;
+-	pfn = min(pfn, zone_end_pfn(zone));
+-	end_page = pfn_to_page(pfn);
+-
+ 	do {
+ 		if (pfn_valid_within(pfn)) {
+ 			if (check_source && PageLRU(page)) {
+@@ -309,7 +316,7 @@ __reset_isolation_pfn(struct zone *zone, unsigned long pfn, bool check_source,
+ static void __reset_isolation_suitable(struct zone *zone)
+ {
+ 	unsigned long migrate_pfn = zone->zone_start_pfn;
+-	unsigned long free_pfn = zone_end_pfn(zone);
++	unsigned long free_pfn = zone_end_pfn(zone) - 1;
+ 	unsigned long reset_migrate = free_pfn;
+ 	unsigned long reset_free = migrate_pfn;
+ 	bool source_set = false;
diff --git a/kernel.spec b/kernel.spec
index a4d474f0e..4b2415f75 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -591,6 +591,9 @@ Patch508: 0001-virt-vbox-Implement-passing-requestor-info-to-the-ho.patch
 # rhbz 1688283
 Patch512: v3-tpm-fix-an-invalid-condition-in-tpm_common_poll.patch
 
+# https://patchwork.kernel.org/patch/10872997/
+Patch513: Correct-zone-boundary-handling-when-resetting-pageblock-skip-hints.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif