On 2 August 2015 at 15:24, Simon Glass sjg@chromium.org wrote:
On 27 July 2015 at 05:16, Bin Meng bmeng.cn@gmail.com wrote:
From: Miao Yan yanmiaobest@gmail.com
When running SMP configuration on QEMU (tcg mode, no kvm), there is a busy loop in start_aps(), calling udelay(), that waits for APs to show up online. However, there is a chance that VCPU1 will be timeout waiting, IOW the secondary VCPUs haven't started their execution yet.
This patch adds a 'pause' instruction in __udelay() only for QEMU target, to give other VCPUs a chance to run. When QEMU sees the 'pause' instruction, it will yeild the execution to other CPUs.
Signed-off-by: Miao Yan yanmiaobest@gmail.com Signed-off-by: Bin Meng bmeng.cn@gmail.com
arch/x86/lib/tsc_timer.c | 8 ++++++++ 1 file changed, 8 insertions(+)
Acked-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org
Applied to u-boot-x86, thanks!