Message ID | 0842431c-fa15-2ba1-ae6d-c1fea157941f@huawei.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v6] arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill() | expand |
On Mon, Oct 21, 2019 at 07:31:21PM +0800, Yunfeng Ye wrote: > In cases like suspend-to-disk and suspend-to-ram, a large number of CPU > cores need to be shut down. At present, the CPU hotplug operation is > serialised, and the CPU cores can only be shut down one by one. In this > process, if PSCI affinity_info() does not return LEVEL_OFF quickly, > cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores > need to be shut down, it will take a long time. > > Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So > change the wait interval from 10 ms to max 1 ms and use usleep_range() > instead of msleep() for more accurate timer. > > In addition, reducing the time interval will increase the messages > output, so remove the "Retry ..." message, instead, track time and > output to the the sucessful message. > > Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Queued for 5.5. Thanks.
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index c9f72b2665f1..43ae4e0c968f 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -81,7 +81,8 @@ static void cpu_psci_cpu_die(unsigned int cpu) static int cpu_psci_cpu_kill(unsigned int cpu) { - int err, i; + int err; + unsigned long start, end; if (!psci_ops.affinity_info) return 0; @@ -91,16 +92,18 @@ static int cpu_psci_cpu_kill(unsigned int cpu) * while it is dying. So, try again a few times. */ - for (i = 0; i < 10; i++) { + start = jiffies; + end = start + msecs_to_jiffies(100); + do { err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { - pr_info("CPU%d killed.\n", cpu); + pr_info("CPU%d killed (polled %d ms)\n", cpu, + jiffies_to_msecs(jiffies - start)); return 0; } - msleep(10); - pr_info("Retrying again to check for CPU kill\n"); - } + usleep_range(100, 1000); + } while (time_before(jiffies, end)); pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", cpu, err);