On Tue, Sep 12, 2023 at 09:08:34AM +0800, Guo Ren wrote: > On Mon, Sep 11, 2023 at 11:34 PM Waiman Long <longman@xxxxxxxxxx> wrote: > > > > On 9/10/23 04:29, guoren@xxxxxxxxxx wrote: > > > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > > > > Allow cmdline to force the kernel to use queued_spinlock when > > > CONFIG_RISCV_COMBO_SPINLOCKS=y. > > > > > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> > > > --- > > > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > > > arch/riscv/kernel/setup.c | 16 +++++++++++++++- > > > 2 files changed, 17 insertions(+), 1 deletion(-) > > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > > index 7dfb540c4f6c..61cacb8dfd0e 100644 > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > @@ -4693,6 +4693,8 @@ > > > [KNL] Number of legacy pty's. Overwrites compiled-in > > > default number. > > > > > > + qspinlock [RISCV] Force to use qspinlock or auto-detect spinlock. > > > + > > > qspinlock.numa_spinlock_threshold_ns= [NUMA, PV_OPS] > > > Set the time threshold in nanoseconds for the > > > number of intra-node lock hand-offs before the > > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > > > index a447cf360a18..0f084f037651 100644 > > > --- a/arch/riscv/kernel/setup.c > > > +++ b/arch/riscv/kernel/setup.c > > > @@ -270,6 +270,15 @@ static void __init parse_dtb(void) > > > } > > > > > > #ifdef CONFIG_RISCV_COMBO_SPINLOCKS > > > +bool enable_qspinlock_key = false; > > > > You can use __ro_after_init qualifier for enable_qspinlock_key. BTW, > > this is not a static key, just a simple flag. So what is the point of > > the _key suffix? > Okay, I would change it to: > bool enable_qspinlock_flag __ro_after_init = false; IIUC, this bool / flag is used in a single file, so it makes sense for it to be static. Being static means it does not need to be initialized to false, as it's standard to zero-fill this areas. Also, since it's a bool, it does not need to be called _flag. I would go with: static bool enable_qspinlock __ro_after_init; > > > > > Cheers, > > Longman > > > > > -- > Best Regards > Guo Ren >
