[ Upstream commit e47110e90584a22e9980510b00d0dfad3a83354e ]
Like zap_pte_range add cond_resched so that we can avoid softlockups as
reported below. On non-preemptible kernel with large I/O map region (like
the one we get when using persistent memory with sector mode), an unmap of
the namespace can report below softlockups.
22724.027334] watchdog: BUG: soft lockup - CPU#49 stuck for 23s! [ndctl:50777]
NIP [c0000000000dc224] plpar_hcall+0x38/0x58
LR [c0000000000d8898] pSeries_lpar_hpte_invalidate+0x68/0xb0
Call Trace:
flush_hash_page+0x114/0x200
hpte_need_flush+0x2dc/0x540
vunmap_page_range+0x538/0x6f0
free_unmap_vmap_area+0x30/0x70
remove_vm_area+0xfc/0x140
__vunmap+0x68/0x270
__iounmap.part.0+0x34/0x60
memunmap+0x54/0x70
release_nodes+0x28c/0x300
device_release_driver_internal+0x16c/0x280
unbind_store+0x124/0x170
drv_attr_store+0x44/0x60
sysfs_kf_write+0x64/0x90
kernfs_fop_write+0x1b0/0x290
__vfs_write+0x3c/0x70
vfs_write+0xd8/0x260
ksys_write+0xdc/0x130
system_call+0x5c/0x70
Reported-by: Harish Sriram <[email protected]>
Signed-off-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: <[email protected]>
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
mm/vmalloc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ad4d00bd79147..5797e1eeaa7e6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -85,6 +85,8 @@ static void vunmap_pmd_range(pud_t *pud, unsigned long addr,
unsigned long end)
if (pmd_none_or_clear_bad(pmd))
continue;
vunmap_pte_range(pmd, addr, next);
+
+ cond_resched();
} while (pmd++, addr = next, addr != end);
}
--
2.25.1
