Hi Babu, On 1/30/25 1:20 PM, Babu Moger wrote: > "io_alloc" feature that enables direct insertion of data from I/O devices > into the L3 cache. Above is not clear to me. Should this maybe be ""io_alloc" enables direct insertion ..." > > On AMD, 'io_alloc" feature is backed by L3 Smart Data Cache Injection (mismatch quotes around io_alloc ... also below) > Allocation Enforcement (SDCIAE). SDCIAE feature can be enabled by setting "can be enabled" -> "is enabled"? > bit 1 in MSR L3_QOS_EXT_CFG. Apply the updated SDCIAE value across all > logical processors within the QOS domain when modifying its state. ... it could also just be "Change SDCIAE state by setting (to enable) or clearing (to disable) bit 1 of MSR L3_QOS_EXT_CFG on all logical processors within the cache domain." > > Introduce architecture-specific handlers to manage the detection and This patch only seem to do the enable/disable with detection done in earlier patch. > enabling/disabling of 'io_alloc" feature. > > The SDCIAE feature details are available in APM listed below [1]. > [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming > Publication # 24593 Revision 3.41 section 19.4.7 L3 Smart Data Cache > Injection Allocation Enforcement (SDCIAE) > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > --- ... > diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h > index dbe6461f3fbc..e77c3b37bad4 100644 > --- a/include/linux/resctrl.h > +++ b/include/linux/resctrl.h > @@ -343,6 +343,15 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d, > */ > void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d); > > +/** > + * resctrl_arch_io_alloc_enable() - Enable/disable io_alloc feature. > + * @r: The resctrl resource. > + * @enable: Enable (1) or disable (0) the feature Please be consistent in using periods at end of sentence. This could be made more specific with: "Enable (true) or disable (false) io_alloc on resource @r." > + * > + * This can be called from any CPU. > + */ > +int resctrl_arch_io_alloc_enable(struct rdt_resource *r, bool enable); > + > extern unsigned int resctrl_rmid_realloc_threshold; > extern unsigned int resctrl_rmid_realloc_limit; > Reinette
