On Fri, 6 Oct 2017 12:54:08 +0530
Shriya <shri...@linux.vnet.ibm.com> wrote:
> Make /proc/cpuinfo read the frequency of the CPU it is running at
> instead of reading the cached value of the last requested frequency.
> In conditions like WOF/throttle CPU can be running at a different
> frequency than the requested frequency.
>
> Signed-off-by: Shriya <shri...@linux.vnet.ibm.com>
This causes the following:
[ 7.203270] BUG: sleeping function called from invalid context at
/home/npiggin/linux/kernel/locking/rwsem.c:23
[ 7.203323] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: systemd
[ 7.203352] 1 lock held by systemd/1:
[ 7.203367] #0: (&p->lock){+.+.}, at: [<c0000000003e12f8>]
seq_read+0x78/0x5c0
[ 7.203416] CPU: 164 PID: 1 Comm: systemd Not tainted
4.14.0-00345-g8fb6e339cdf5 #33
[ 7.203452] Call Trace:
[ 7.203463] [c000000ff55039d0] [c000000000be4f24] dump_stack+0x104/0x190
(unreliable)
[ 7.203502] [c000000ff5503a10] [c0000000001297d0] ___might_sleep+0x2e0/0x320
[ 7.203539] [c000000ff5503a90] [c000000000c049fc] down_read+0x3c/0xc0
[ 7.203569] [c000000ff5503ad0] [c0000000009f7c70] cpufreq_get+0x50/0xc0
[ 7.203600] [c000000ff5503b20] [c000000000093618] pnv_get_proc_freq+0x28/0x60
[ 7.203637] [c000000ff5503b50] [c00000000002bfc0] show_cpuinfo+0x1b0/0x460
[ 7.203667] [c000000ff5503c00] [c0000000003e14b8] seq_read+0x238/0x5c0
[ 7.203698] [c000000ff5503ca0] [c000000000441e80] proc_reg_read+0xb0/0x110
[ 7.203729] [c000000ff5503cf0] [c0000000003a16cc] __vfs_read+0x6c/0x1c0
[ 7.203759] [c000000ff5503d90] [c0000000003a18dc] vfs_read+0xbc/0x1b0
[ 7.203788] [c000000ff5503de0] [c0000000003a20cc] SyS_read+0x6c/0x110
[ 7.203819] [c000000ff5503e30] [c00000000000b82c] system_call+0x58/0x6c
> arch/powerpc/platforms/powernv/setup.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/powernv/setup.c
> b/arch/powerpc/platforms/powernv/setup.c
> index 897aa14..55ea4bf 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -311,7 +311,7 @@ static unsigned long pnv_get_proc_freq(unsigned int cpu)
> {
> unsigned long ret_freq;
>
> - ret_freq = cpufreq_quick_get(cpu) * 1000ul;
> + ret_freq = cpufreq_get(cpu) * 1000ul;
>
> /*
> * If the backend cpufreq driver does not exist,
