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FAILED: patch "[PATCH] mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong" failed to apply to 6.6-stable tree

PATCH [email protected] 1 participant 1 message Mar 4, 2024

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The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 2774f256e7c0219e2b0a0894af1c76bdabc4f974
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024030455-recite-camera-0413@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

2774f256e7c0 ("mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index") 2ac9e99f3b21 ("mm: migrate: convert numamigrate_isolate_page() to numamigrate_isolate_folio()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2774f256e7c0219e2b0a0894af1c76bdabc4f974 Mon Sep 17 00:00:00 2001
From: Byungchul Park <[email protected]>
Date: Fri, 16 Feb 2024 20:15:02 +0900
Subject: [PATCH] mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong
zone index

With numa balancing on, when a numa system is running where a numa node doesn't have its local memory so it has no managed zones, the following oops has been observed. It's because wakeup_kswapd() is called with a wrong zone index, -1. Fixed it by checking the index before calling wakeup_kswapd().

Quoted 36 lines
BUG: unable to handle page fault for address: 00000000000033f3
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
   rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812)
Code: (omitted)
RSP: 0000:ffffc90004257d58 EFLAGS: 00010286
RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480
RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff
R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940
FS:  00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>

? __die
? page_fault_oops
? __pte_offset_map_lock
? exc_page_fault
? asm_exc_page_fault
? wakeup_kswapd
migrate_misplaced_page
__handle_mm_fault
handle_mm_fault
do_user_addr_fault
exc_page_fault
asm_exc_page_fault

Quoted 9 lines
RIP: 0033:0x55b897ba0808
Code: (omitted)
RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287
RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0
RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0
RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000
 </TASK>
Link https://lkml.kernel.org/r/[email protected] open here
Signed-off-by Byungchul Park <[email protected]>
Reported-by Hyeongtak Ji <[email protected]>
Fixes c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system")
Reviewed-by Oscar Salvador <[email protected]>
Cc Baolin Wang <[email protected]>
Cc "Huang, Ying" <[email protected]>
Cc Johannes Weiner <[email protected]>
Cc <[email protected]>
Signed-off-by Andrew Morton <[email protected]>
mm/migrate.c +8 -0
index cc9f2bcd73b4..c27b1f8097d4 100644
@@ -2519,6 +2519,14 @@ static int numamigrate_isolate_folio(pg_data_t *pgdat, struct folio *folio)
 			if (managed_zone(pgdat->node_zones + z))
 				break;
 		}
+
+		/*
+		 * If there are no managed zones, it should not proceed
+		 * further.
+		 */
+		if (z < 0)
+			return 0;
+
 		wakeup_kswapd(pgdat->node_zones + z, 0,
 			      folio_order(folio), ZONE_MOVABLE);
 		return 0;