This is a note to let you know that I've just added the patch titled parisc: Use cr16 interval timers unconditionally on qemu to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-use-cr16-interval-timers-unconditionally-on-qemu.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5ffa8518851f1401817c15d2a7eecc0373c26ff9 Mon Sep 17 00:00:00 2001 From: Helge Deller <deller@xxxxxx> Date: Fri, 12 Jan 2018 22:44:00 +0100 Subject: parisc: Use cr16 interval timers unconditionally on qemu From: Helge Deller <deller@xxxxxx> commit 5ffa8518851f1401817c15d2a7eecc0373c26ff9 upstream. When running on qemu we know that the (emulated) cr16 cpu-internal clocks are syncronized. So let's use them unconditionally on qemu. Signed-off-by: Helge Deller <deller@xxxxxx> Cc: stable@xxxxxxxxxxxxxxx # 4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/parisc/include/asm/processor.h | 2 ++ arch/parisc/kernel/time.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -316,6 +316,8 @@ extern int _parisc_requires_coherency; #define parisc_requires_coherency() (0) #endif +extern int running_on_qemu; + #endif /* __ASSEMBLY__ */ #endif /* __ASM_PARISC_PROCESSOR_H */ --- a/arch/parisc/kernel/time.c +++ b/arch/parisc/kernel/time.c @@ -248,7 +248,7 @@ static int __init init_cr16_clocksource( * different sockets, so mark them unstable and lower rating on * multi-socket SMP systems. */ - if (num_online_cpus() > 1) { + if (num_online_cpus() > 1 && !running_on_qemu) { int cpu; unsigned long cpu0_loc; cpu0_loc = per_cpu(cpu_data, 0).cpu_loc; Patches currently in stable-queue which might be from deller@xxxxxx are queue-4.15/parisc-hide-virtual-kernel-memory-layout.patch queue-4.15/parisc-use-cr16-interval-timers-unconditionally-on-qemu.patch queue-4.15/parisc-fix-ordering-of-cache-and-tlb-flushes.patch queue-4.15/parisc-reduce-irq-overhead-when-run-in-qemu.patch