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authorYisheng Xie <xieyisheng1@huawei.com>2017-11-29 16:11:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-29 18:40:43 -0800
commitbde5f6bc68db51128f875a756e9082a6c6ff7b4c (patch)
tree76d26ad04100d9b378fc2ad520b299c69fef528f /mm
parentedbddb83a15b4361d8c3bf00aabee85fd3ef4d80 (diff)
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kmemleak: add scheduling point to kmemleak_scan()
kmemleak_scan() will scan struct page for each node and it can be really large and resulting in a soft lockup. We have seen a soft lockup when do scan while compile kernel: watchdog: BUG: soft lockup - CPU#53 stuck for 22s! [bash:10287] [...] Call Trace: kmemleak_scan+0x21a/0x4c0 kmemleak_write+0x312/0x350 full_proxy_write+0x5a/0xa0 __vfs_write+0x33/0x150 vfs_write+0xad/0x1a0 SyS_write+0x52/0xc0 do_syscall_64+0x61/0x1a0 entry_SYSCALL64_slow_path+0x25/0x25 Fix this by adding cond_resched every MAX_SCAN_SIZE. Link: http://lkml.kernel.org/r/1511439788-20099-1-git-send-email-xieyisheng1@huawei.com Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/kmemleak.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e4738d5e9b8c..3d4781756d50 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1523,6 +1523,8 @@ static void kmemleak_scan(void)
if (page_count(page) == 0)
continue;
scan_block(page, page + 1, NULL);
+ if (!(pfn % (MAX_SCAN_SIZE / sizeof(*page))))
+ cond_resched();
}
}
put_online_mems();