The patch titled
Subject: mm/hotplug, powerpc: fix an imbalance with DEBUG_PAGEALLOC
has been added to the -mm tree. Its filename is
mm-hotplug-fix-an-imbalance-with-debug_pagealloc.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hotplug-fix-an-imbalance-with-debug_pagealloc.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hotplug-fix-an-imbalance-with-debug_pagealloc.patch
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------------------------------------------------------
From: Qian Cai <cai@xxxxxx>
Subject: mm/hotplug, powerpc: fix an imbalance with DEBUG_PAGEALLOC
When onlining memory pages, it calls kernel_unmap_linear_page(), However,
it does not call kernel_map_linear_page() while offlining memory pages.
As the result, it triggers a panic below while onlining on ppc64le as it
checks if the pages are mapped before unmapping, Therefore, let it call
kernel_map_linear_page() when setting all pages as reserved.
kernel BUG at arch/powerpc/mm/hash_utils_64.c:1815!
Oops: Exception in kernel mode, sig: 5 [#1]
LE SMP NR_CPUS=256 DEBUG_PAGEALLOC NUMA pSeries
CPU: 2 PID: 4298 Comm: bash Not tainted 5.0.0-rc7+ #15
NIP: c000000000062670 LR: c00000000006265c CTR: 0000000000000000
REGS: c0000005bf8a75b0 TRAP: 0700 Not tainted (5.0.0-rc7+)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28422842 XER: 00000000
CFAR: c000000000804f44 IRQMASK: 1
GPR00: c00000000006265c c0000005bf8a7840 c000000001518200 c0000000013cbcc8
GPR04: 0000000000080004 0000000000000000 00000000ccc457e0 c0000005c4e341d8
GPR08: 0000000000000000 0000000000000001 c000000007f4f800 0000000000000001
GPR12: 0000000000002200 c000000007f4e100 0000000000000000 0000000139c29710
GPR16: 0000000139c29714 0000000139c29788 c0000000013cbcc8 0000000000000000
GPR20: 0000000000034000 c0000000016e05e8 0000000000000000 0000000000000001
GPR24: 0000000000bf50d9 800000000000018e 0000000000000000 c0000000016e04b8
GPR28: f000000000d00040 0000006420a2f217 f000000000d00000 00ea1b2170340000
NIP [c000000000062670] __kernel_map_pages+0x2e0/0x4f0
LR [c00000000006265c] __kernel_map_pages+0x2cc/0x4f0
Call Trace:
[c0000005bf8a7840] [c00000000006265c] __kernel_map_pages+0x2cc/0x4f0 (unreliable)
[c0000005bf8a78d0] [c00000000028c4a0] free_unref_page_prepare+0x2f0/0x4d0
[c0000005bf8a7930] [c000000000293144] free_unref_page+0x44/0x90
[c0000005bf8a7970] [c00000000037af24] __online_page_free+0x84/0x110
[c0000005bf8a79a0] [c00000000037b6e0] online_pages_range+0xc0/0x150
[c0000005bf8a7a00] [c00000000005aaa8] walk_system_ram_range+0xc8/0x120
[c0000005bf8a7a50] [c00000000037e710] online_pages+0x280/0x5a0
[c0000005bf8a7b40] [c0000000006419e4] memory_subsys_online+0x1b4/0x270
[c0000005bf8a7bb0] [c000000000616720] device_online+0xc0/0xf0
[c0000005bf8a7bf0] [c000000000642570] state_store+0xc0/0x180
[c0000005bf8a7c30] [c000000000610b2c] dev_attr_store+0x3c/0x60
[c0000005bf8a7c50] [c0000000004c0a50] sysfs_kf_write+0x70/0xb0
[c0000005bf8a7c90] [c0000000004bf40c] kernfs_fop_write+0x10c/0x250
[c0000005bf8a7ce0] [c0000000003e4b18] __vfs_write+0x48/0x240
[c0000005bf8a7d80] [c0000000003e4f68] vfs_write+0xd8/0x210
[c0000005bf8a7dd0] [c0000000003e52f0] ksys_write+0x70/0x120
[c0000005bf8a7e20] [c00000000000b000] system_call+0x5c/0x70
Instruction dump:
7fbd5278 7fbd4a78 3e42ffeb 7bbd0640 3a523ac8 7e439378 487a2881 60000000
e95505f0 7e6aa0ae 6a690080 7929c9c2 <0b090000> 7f4aa1ae 7e439378 487a28dd
Link: http://lkml.kernel.org/r/20190225191710.48131-1-cai@xxxxxx
Signed-off-by: Qian Cai <cai@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/page_alloc.c~mm-hotplug-fix-an-imbalance-with-debug_pagealloc
+++ a/mm/page_alloc.c
@@ -8349,6 +8349,7 @@ __offline_isolated_pages(unsigned long s
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
+ kernel_map_pages(page, 1 << order, 1);
}
spin_unlock_irqrestore(&zone->lock, flags);
}
_
Patches currently in -mm which might be from cai@xxxxxx are
page_poison-play-nicely-with-kasan.patch
slab-kmemleak-no-scan-alien-caches.patch
slub-remove-an-unused-addr-argument.patch
mm-compaction-be-selective-about-what-pageblocks-to-clear-skip-hints-fix.patch
mm-hotplug-fix-an-imbalance-with-debug_pagealloc.patch
signal-allow-the-null-signal-in-rt_sigqueueinfo.patch
