The following commit has been merged into the perf/core branch of tip: Commit-ID: 33cad284497cf40f55ad6029c06011de3538ebed Gitweb: https://git.kernel.org/tip/33cad284497cf40f55ad6029c06011de3538ebed Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> AuthorDate: Fri, 03 Jul 2020 05:49:23 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Wed, 08 Jul 2020 11:38:55 +02:00 perf/x86/intel/lbr: Create kmem_cache for the LBR context data A new kmem_cache method is introduced to allocate the PMU specific data task_ctx_data, which requires the PMU specific code to create a kmem_cache. Currently, the task_ctx_data is only used by the Intel LBR call stack feature, which is introduced since Haswell. The kmem_cache should be only created for Haswell and later platforms. There is no alignment requirement for the existing platforms. Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/1593780569-62993-18-git-send-email-kan.liang@xxxxxxxxxxxxxxx --- arch/x86/events/intel/lbr.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index e4e249a..e784c1d 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1531,9 +1531,17 @@ void __init intel_pmu_lbr_init_snb(void) */ } +static inline struct kmem_cache * +create_lbr_kmem_cache(size_t size, size_t align) +{ + return kmem_cache_create("x86_lbr", size, align, 0, NULL); +} + /* haswell */ void intel_pmu_lbr_init_hsw(void) { + size_t size = sizeof(struct x86_perf_task_context); + x86_pmu.lbr_nr = 16; x86_pmu.lbr_tos = MSR_LBR_TOS; x86_pmu.lbr_from = MSR_LBR_NHM_FROM; @@ -1542,6 +1550,8 @@ void intel_pmu_lbr_init_hsw(void) x86_pmu.lbr_sel_mask = LBR_SEL_MASK; x86_pmu.lbr_sel_map = hsw_lbr_sel_map; + x86_get_pmu()->task_ctx_cache = create_lbr_kmem_cache(size, 0); + if (lbr_from_signext_quirk_needed()) static_branch_enable(&lbr_from_quirk_key); } @@ -1549,6 +1559,8 @@ void intel_pmu_lbr_init_hsw(void) /* skylake */ __init void intel_pmu_lbr_init_skl(void) { + size_t size = sizeof(struct x86_perf_task_context); + x86_pmu.lbr_nr = 32; x86_pmu.lbr_tos = MSR_LBR_TOS; x86_pmu.lbr_from = MSR_LBR_NHM_FROM; @@ -1558,6 +1570,8 @@ __init void intel_pmu_lbr_init_skl(void) x86_pmu.lbr_sel_mask = LBR_SEL_MASK; x86_pmu.lbr_sel_map = hsw_lbr_sel_map; + x86_get_pmu()->task_ctx_cache = create_lbr_kmem_cache(size, 0); + /* * SW branch filter usage: * - support syscall, sysret capture. @@ -1631,6 +1645,7 @@ void __init intel_pmu_arch_lbr_init(void) union cpuid28_ebx ebx; union cpuid28_ecx ecx; unsigned int unused_edx; + size_t size; u64 lbr_nr; /* Arch LBR Capabilities */ @@ -1655,8 +1670,10 @@ void __init intel_pmu_arch_lbr_init(void) x86_pmu.lbr_br_type = ecx.split.lbr_br_type; x86_pmu.lbr_nr = lbr_nr; - x86_get_pmu()->task_ctx_size = sizeof(struct x86_perf_task_context_arch_lbr) + - lbr_nr * sizeof(struct lbr_entry); + size = sizeof(struct x86_perf_task_context_arch_lbr) + + lbr_nr * sizeof(struct lbr_entry); + x86_get_pmu()->task_ctx_size = size; + x86_get_pmu()->task_ctx_cache = create_lbr_kmem_cache(size, 0); x86_pmu.lbr_from = MSR_ARCH_LBR_FROM_0; x86_pmu.lbr_to = MSR_ARCH_LBR_TO_0;
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