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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2020-08-21 03:42:05 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-21 19:52:53 +0300
commite47110e90584a22e9980510b00d0dfad3a83354e (patch)
tree6c7a5632412234f5f1fef5bb8fe835abb788948f /mm
parentf3f99d63a8156c7a4a6b20aac22b53c5579c7dc1 (diff)
downloadlinux-e47110e90584a22e9980510b00d0dfad3a83354e.tar.xz
mm/vunmap: add cond_resched() in vunmap_pmd_range
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 <harish@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200807075933.310240-1-aneesh.kumar@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmalloc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index b482d240f9a2..be4724b916b3 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -104,6 +104,8 @@ 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, mask);
+
+ cond_resched();
} while (pmd++, addr = next, addr != end);
}