[dpdk-dev] [PATCH] eal: add umonitor umwait to x86 cpuflags

[McDaniel, Timothy]

> -----Original Message-----
> From: Ananyev, Konstantin <konstantin.ananyev at intel.com>
> Sent: Friday, September 11, 2020 11:37 AM
> To: McDaniel, Timothy <timothy.mcdaniel at intel.com>; Richardson, Bruce
> <bruce.richardson at intel.com>
> Cc: dev at dpdk.org; Carrillo, Erik G <erik.g.carrillo at intel.com>; Eads, Gage
> <gage.eads at intel.com>; Van Haaren, Harry <harry.van.haaren at intel.com>;
> Ma, Liang J <liang.j.ma at intel.com>; Burakov, Anatoly
> <anatoly.burakov at intel.com>
> Subject: RE: [PATCH] eal: add umonitor umwait to x86 cpuflags
> 
> 
> >
> > umonitor/umwait are user-level versions of the monitor/mwait
> > instructions. These allow the core to wait in a low-power state
> > until a specified cache line is accessed, a timeout occurs,
> > or the core is interrupted.
> 
> Isn't it a duplicate to:
> https://patches.dpdk.org/patch/76554/
> ?
> 
> >
> > Signed-off-by: Timothy McDaniel <timothy.mcdaniel at intel.com>
> > ---
> >  lib/librte_eal/x86/include/rte_cpuflags.h | 1 +
> >  lib/librte_eal/x86/rte_cpuflags.c         | 1 +
> >  2 files changed, 2 insertions(+)
> >
> > diff --git a/lib/librte_eal/x86/include/rte_cpuflags.h
> b/lib/librte_eal/x86/include/rte_cpuflags.h
> > index c1d2036..ab2c3b3 100644
> > --- a/lib/librte_eal/x86/include/rte_cpuflags.h
> > +++ b/lib/librte_eal/x86/include/rte_cpuflags.h
> > @@ -130,6 +130,7 @@ enum rte_cpu_flag_t {
> >  	RTE_CPUFLAG_CLDEMOTE,               /**< Cache Line Demote */
> >  	RTE_CPUFLAG_MOVDIRI,                /**< Direct Store Instructions */
> >  	RTE_CPUFLAG_MOVDIR64B,              /**< Direct Store Instructions 64B
> */
> > +	RTE_CPUFLAG_UMWAIT,                 /**< UMONITOR/UMWAIT */
> >  	RTE_CPUFLAG_AVX512VP2INTERSECT,     /**< AVX512 Two Register
> Intersection */
> >
> >  	/* The last item */
> > diff --git a/lib/librte_eal/x86/rte_cpuflags.c b/lib/librte_eal/x86/rte_cpuflags.c
> > index 30439e7..6bed3eb 100644
> > --- a/lib/librte_eal/x86/rte_cpuflags.c
> > +++ b/lib/librte_eal/x86/rte_cpuflags.c
> > @@ -137,6 +137,7 @@ const struct feature_entry rte_cpu_feature_table[] = {
> >  	FEAT_DEF(CLDEMOTE, 0x00000007, 0, RTE_REG_ECX, 25)
> >  	FEAT_DEF(MOVDIRI, 0x00000007, 0, RTE_REG_ECX, 27)
> >  	FEAT_DEF(MOVDIR64B, 0x00000007, 0, RTE_REG_ECX, 28)
> > +	FEAT_DEF(UMWAIT, 0x00000007, 0, RTE_REG_ECX, 5)
> >  	FEAT_DEF(AVX512VP2INTERSECT, 0x00000007, 0, RTE_REG_EDX, 8)
> >  };
> >
> > --
> > 2.6.4

With regards to the dependency on part of the power patch set (first patch in the WAITPKG patch series  http://patches.dpdk.org/project/dpdk/list/?series=12669 ), we understand the power team are addressing any outstanding issues today.
This should allow the DLB (https://patches.dpdk.org/project/dpdk/list/?series=12163) and DLB2 (https://patches.dpdk.org/project/dpdk/list/?series=12164) patch sets to make use of the CPU ID patch as planned.
Let us know if there is anything else outstanding. We are currently working towards the PMD merge deadline date.

Thanks, Tim