Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 4.14 078/100] kmemleak: add scheduling point to kmemleak_scan() | Date | Wed, 24 Jan 2018 04:15:05 +0000 |
| |
From: Yisheng Xie <xieyisheng1@huawei.com>
[ Upstream commit bde5f6bc68db51128f875a756e9082a6c6ff7b4c ]
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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- mm/kmemleak.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 7780cd83a495..a1ba553816eb 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1532,6 +1532,8 @@ 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(); -- 2.11.0
| |