From: Jialin Zhang zhangjialin11@huawei.com

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I47W8L CVE: NA

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Adding a padding before timekeeper in tk_core can futhor fix the false sharing problem discovered by commit 605276666775 ("timekeeping: Avoiding false sharing in field access of tk_core")

context1 of unixbench is tested on Huawei Kunpeng920. before this patch 0 CPUs in system; running 96 parallel copies of tests

Pipe-based Context Switching 17213571.7 lps (10.0 s, 1 samples)

System Benchmarks Partial Index BASELINE RESULT INDEX Pipe-based Context Switching 4000.0 17213571.7 43033.9 ======== System Benchmarks Index Score (Partial Only) 43033.9

after this patch 0 CPUs in system; running 96 parallel copies of tests

Pipe-based Context Switching 20321268.3 lps (10.0 s, 1 samples)

System Benchmarks Partial Index BASELINE RESULT INDEX Pipe-based Context Switching 4000.0 20321268.3 50803.2 ======== System Benchmarks Index Score (Partial Only) 50803.2

Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- kernel/time/timekeeping.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e3142bf7648e..c8d9b89a7571 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -52,6 +52,9 @@ static struct { u64 padding[8]; #endif seqcount_raw_spinlock_t seq; +#ifdef CONFIG_ARCH_LLC_128_LINE_SIZE + u64 padding2[2]; +#endif struct timekeeper timekeeper; #ifdef CONFIG_ARCH_LLC_128_LINE_SIZE } tk_core ____cacheline_aligned_128 = {