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x86/resctrl: Fix to restore to original value when re-enabling hardware prefetch register
[ Upstream commit499c8bb469
] The current pseudo_lock.c code overwrites the value of the MSR_MISC_FEATURE_CONTROL to 0 even if the original value is not 0. Therefore, modify it to save and restore the original values. Fixes:018961ae55
("x86/intel_rdt: Pseudo-lock region creation/removal core") Fixes:443810fe61
("x86/intel_rdt: Create debugfs files for pseudo-locking testing") Fixes:8a2fc0e1bc
("x86/intel_rdt: More precise L2 hit/miss measurements") Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lkml.kernel.org/r/eb660f3c2010b79a792c573c02d01e8e841206ad.1661358182.git.reinette.chatre@intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
bbe293db7e
commit
7993680752
1 changed files with 9 additions and 3 deletions
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@ -416,6 +416,7 @@ static int pseudo_lock_fn(void *_rdtgrp)
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struct pseudo_lock_region *plr = rdtgrp->plr;
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u32 rmid_p, closid_p;
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unsigned long i;
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u64 saved_msr;
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#ifdef CONFIG_KASAN
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/*
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* The registers used for local register variables are also used
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@ -459,6 +460,7 @@ static int pseudo_lock_fn(void *_rdtgrp)
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* the buffer and evict pseudo-locked memory read earlier from the
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* cache.
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*/
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saved_msr = __rdmsr(MSR_MISC_FEATURE_CONTROL);
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__wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0);
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closid_p = this_cpu_read(pqr_state.cur_closid);
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rmid_p = this_cpu_read(pqr_state.cur_rmid);
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@ -510,7 +512,7 @@ static int pseudo_lock_fn(void *_rdtgrp)
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__wrmsr(IA32_PQR_ASSOC, rmid_p, closid_p);
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/* Re-enable the hardware prefetcher(s) */
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wrmsr(MSR_MISC_FEATURE_CONTROL, 0x0, 0x0);
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wrmsrl(MSR_MISC_FEATURE_CONTROL, saved_msr);
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local_irq_enable();
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plr->thread_done = 1;
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@ -867,6 +869,7 @@ bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d)
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static int measure_cycles_lat_fn(void *_plr)
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{
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struct pseudo_lock_region *plr = _plr;
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u32 saved_low, saved_high;
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unsigned long i;
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u64 start, end;
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void *mem_r;
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@ -875,6 +878,7 @@ static int measure_cycles_lat_fn(void *_plr)
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/*
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* Disable hardware prefetchers.
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*/
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rdmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
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wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0);
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mem_r = READ_ONCE(plr->kmem);
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/*
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@ -891,7 +895,7 @@ static int measure_cycles_lat_fn(void *_plr)
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end = rdtsc_ordered();
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trace_pseudo_lock_mem_latency((u32)(end - start));
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}
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wrmsr(MSR_MISC_FEATURE_CONTROL, 0x0, 0x0);
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wrmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
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local_irq_enable();
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plr->thread_done = 1;
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wake_up_interruptible(&plr->lock_thread_wq);
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@ -936,6 +940,7 @@ static int measure_residency_fn(struct perf_event_attr *miss_attr,
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u64 hits_before = 0, hits_after = 0, miss_before = 0, miss_after = 0;
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struct perf_event *miss_event, *hit_event;
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int hit_pmcnum, miss_pmcnum;
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u32 saved_low, saved_high;
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unsigned int line_size;
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unsigned int size;
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unsigned long i;
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@ -969,6 +974,7 @@ static int measure_residency_fn(struct perf_event_attr *miss_attr,
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/*
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* Disable hardware prefetchers.
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*/
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rdmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
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wrmsr(MSR_MISC_FEATURE_CONTROL, prefetch_disable_bits, 0x0);
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/* Initialize rest of local variables */
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@ -1027,7 +1033,7 @@ static int measure_residency_fn(struct perf_event_attr *miss_attr,
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*/
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rmb();
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/* Re-enable hardware prefetchers */
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wrmsr(MSR_MISC_FEATURE_CONTROL, 0x0, 0x0);
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wrmsr(MSR_MISC_FEATURE_CONTROL, saved_low, saved_high);
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local_irq_enable();
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out_hit:
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perf_event_release_kernel(hit_event);
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