Hi Thomas, On 2/19/2018 1:19 PM, Thomas Gleixner wrote: > On Tue, 13 Feb 2018, Reinette Chatre wrote: > >> After a pseudo-locked region is locked it needs to be associated with >> the RDT domain representing the pseudo-locked cache so that its life >> cycle can be managed correctly. >> >> Only a single pseudo-locked region can exist on any cache instance so we >> maintain a single pointer to a pseudo-locked region from each RDT >> domain. > > Why is only a single pseudo locked region possible?
The setup of a pseudo-locked region requires the usage of wbinvd. If a second pseudo-locked region is thus attempted it will evict the pseudo-locked data of the first. > >> Signed-off-by: Reinette Chatre <reinette.cha...@intel.com> >> --- >> arch/x86/kernel/cpu/intel_rdt.h | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/x86/kernel/cpu/intel_rdt.h >> b/arch/x86/kernel/cpu/intel_rdt.h >> index 060a0976ac00..f0e020686e99 100644 >> --- a/arch/x86/kernel/cpu/intel_rdt.h >> +++ b/arch/x86/kernel/cpu/intel_rdt.h >> @@ -187,6 +187,8 @@ struct mbm_state { >> u64 prev_msr; >> }; >> >> +struct pseudo_lock_region; >> + >> /** >> * struct rdt_domain - group of cpus sharing an RDT resource >> * @list: all instances of this resource >> @@ -205,6 +207,7 @@ struct mbm_state { >> * @ctrl_val: array of cache or mem ctrl values (indexed by CLOSID) >> * @new_ctrl: new ctrl value to be loaded >> * @have_new_ctrl: did user provide new_ctrl for this domain >> + * @plr: pseudo-locked region associated with this domain >> */ >> struct rdt_domain { >> struct list_head list; >> @@ -220,6 +223,7 @@ struct rdt_domain { >> u32 *ctrl_val; >> u32 new_ctrl; >> bool have_new_ctrl; >> + struct pseudo_lock_region *plr; > > Please keep the tabular fashion of the struct declaration intact. Will fix. Reinette