Messages in this thread | | | Date | Wed, 1 Nov 2023 16:43:12 +0700 | From | Bagas Sanjaya <> | Subject | Re: [PATCH] x86/resctrl: Fix unused variable warning in cache_alloc_hsw_probe() |
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On Tue, Oct 31, 2023 at 03:05:34PM -0700, Tony Luck wrote: > In a "W=1" build gcc throws a warning: > > arch/x86/kernel/cpu/resctrl/core.c: In function ‘cache_alloc_hsw_probe’: > arch/x86/kernel/cpu/resctrl/core.c:139:16: warning: variable ‘h’ set but not used > > Fix by switching from rdmsr() to rdmsrl() using a single u64 argument > for the MSR value instead of the pair of u32 for the high and low > halves. > > Signed-off-by: Tony Luck <tony.luck@intel.com> > --- > This has been annoying me for a while as the only warning from the > resctrl code when building with W=1. > > N.B. compile tested only. I don't have a Haswell system to check this works. > > arch/x86/kernel/cpu/resctrl/core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c > index 19e0681f0435..4084131d391d 100644 > --- a/arch/x86/kernel/cpu/resctrl/core.c > +++ b/arch/x86/kernel/cpu/resctrl/core.c > @@ -136,15 +136,16 @@ static inline void cache_alloc_hsw_probe(void) > { > struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_L3]; > struct rdt_resource *r = &hw_res->r_resctrl; > - u32 l, h, max_cbm = BIT_MASK(20) - 1; > + u32 max_cbm = BIT_MASK(20) - 1; > + u64 l3_cbm_0; > > if (wrmsr_safe(MSR_IA32_L3_CBM_BASE, max_cbm, 0)) > return; > > - rdmsr(MSR_IA32_L3_CBM_BASE, l, h); > + rdmsrl(MSR_IA32_L3_CBM_BASE, l3_cbm_0); > > /* If all the bits were set in MSR, return success */ > - if (l != max_cbm) > + if (l3_cbm_0 != max_cbm) > return; > > hw_res->num_closid = 4;
No noticeable regressions on my Acer Aspire E15 (the laptop uses Intel Core i3 Haswell), thanks!
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
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