On Tue, Jun 09, 2015 at 05:05:43PM +0800, Borislav Petkov wrote: > On Tue, Jun 09, 2015 at 11:13:39AM +0800, Huang Rui wrote: > > This patch introduces a kernel parameter (delay), user is able to configure > > it at boot loader to choose different types of delay method. > > > > Default schema is to use TSC delay. This update can be more flexiable to > > add new delay method. > > > > Suggested-by: Suravee Suthikulanit <[email protected]> > > Signed-off-by: Huang Rui <[email protected]> > > --- > > arch/x86/include/asm/delay.h | 7 +++++++ > > arch/x86/kernel/setup.c | 19 +++++++++++++++++++ > > arch/x86/lib/delay.c | 12 +++++++++++- > > 3 files changed, 37 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/include/asm/delay.h b/arch/x86/include/asm/delay.h > > index 9b3b4f2..99873ec 100644 > > --- a/arch/x86/include/asm/delay.h > > +++ b/arch/x86/include/asm/delay.h > > @@ -5,4 +5,11 @@ > > > > void use_tsc_delay(void); > > > > +extern unsigned long boot_option_delay; > > + > > +enum delay_type { > > + DELAY_LOOP=0, > > + DELAY_TSC, > > +}; > > + > > #endif /* _ASM_X86_DELAY_H */ > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > > index 0b10698..cc2886d 100644 > > --- a/arch/x86/kernel/setup.c > > +++ b/arch/x86/kernel/setup.c > > @@ -111,6 +111,7 @@ > > #include <asm/mce.h> > > #include <asm/alternative.h> > > #include <asm/prom.h> > > +#include <asm/delay.h> > > > > /* > > * max_low_pfn_mapped: highest direct mapped pfn under 4GB > > @@ -844,6 +845,24 @@ dump_kernel_offset(struct notifier_block *self, > > unsigned long v, void *p) > > return 0; > > } > > > > +static int __init delay_setup(char *str) > > +{ > > + if (!str) > > + return -EINVAL; > > + > > + if (!strcmp(str, "tsc")) { > > + pr_info("using tsc delay\n"); > > + boot_option_delay = DELAY_TSC; > > + } else if (!strcmp(str, "loop")) { > > + pr_info("using loop delay\n"); > > + boot_option_delay = DELAY_LOOP; > > + } else > > + return -1; > > What Peter said. > > And we did talk about this already in the last review. You guys want to > drop all those kernel parameters and use MWAITX delay by default when: > > 1. HW supports MWAITX > > *and* > > 2. delay fits in u32. > > Kernel parameters is a bad bad idea. >
Sorry, I am suggested to make the mwaitx delay configurable firstly by our guys... Why do you think that method is bad? Thanks, Rui -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
