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[Deepin-Kernel-SIG] [linux 6.6-y] [Upstream] [Intel] Backport bugfixes for SRF LBR branch counter #838

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Merged
opsiff merged 3 commits into from
Jun 2, 2025
Merged

[Deepin-Kernel-SIG] [linux 6.6-y] [Upstream] [Intel] Backport bugfixes for SRF LBR branch counter #838

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8972d16
perf/x86/intel: Only check the group flag for X86 leader
Apr 24, 2025
125c39d
perf/x86/intel: Allow to setup LBR for counting event for BPF
Sep 9, 2024
a6bec4d
Merge branch 'deepin-community:linux-6.6.y' into linux-6.6.y
Jun 2, 2025
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2 changes: 1 addition & 1 deletion arch/x86/events/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -748,7 +748,7 @@ void x86_pmu_enable_all(int added)
}
}

static inline int is_x86_event(struct perf_event *event)
int is_x86_event(struct perf_event *event)
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Copilot AI Jun 2, 2025

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[nitpick] Since is_x86_event returns a boolean-like result, consider changing its return type to bool for clarity and consistency with other predicate functions.

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{
int i;

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8 changes: 6 additions & 2 deletions arch/x86/events/intel/core.c
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Expand Up @@ -4002,8 +4002,12 @@ static int intel_pmu_hw_config(struct perf_event *event)
x86_pmu.pebs_aliases(event);
}

if (needs_branch_stack(event) && is_sampling_event(event))
event->hw.flags |= PERF_X86_EVENT_NEEDS_BRANCH_STACK;
if (needs_branch_stack(event)) {
/* Avoid branch stack setup for counting events in SAMPLE READ */
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@sourcery-ai sourcery-ai Bot Jun 2, 2025

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suggestion: Clarify SAMPLE_READ logic in comment

Consider updating the comment to clarify that branch stack setup is skipped only when the event is not a sampling event and PERF_SAMPLE_READ is set.

Suggested change
/* Avoid branch stack setup for counting events in SAMPLE READ */
/* Skip branch stack setup only for non-sampling events with PERF_SAMPLE_READ set */

if (is_sampling_event(event) ||
!(event->attr.sample_type & PERF_SAMPLE_READ))
event->hw.flags |= PERF_X86_EVENT_NEEDS_BRANCH_STACK;
Comment on lines +4008 to +4009
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Copilot AI Jun 2, 2025

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[nitpick] Consider adding braces around the inner if block to improve readability and prevent accidental inclusion of additional statements in future edits.

Suggested change
!(event->attr.sample_type & PERF_SAMPLE_READ))
event->hw.flags |= PERF_X86_EVENT_NEEDS_BRANCH_STACK;
!(event->attr.sample_type & PERF_SAMPLE_READ)) {
event->hw.flags |= PERF_X86_EVENT_NEEDS_BRANCH_STACK;
}

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}

if (branch_sample_counters(event)) {
struct perf_event *leader, *sibling;
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9 changes: 8 additions & 1 deletion arch/x86/events/perf_event.h
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Expand Up @@ -110,9 +110,16 @@ static inline bool is_topdown_event(struct perf_event *event)
return is_metric_event(event) || is_slots_event(event);
}

int is_x86_event(struct perf_event *event);
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Copilot AI Jun 2, 2025

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Add a brief comment describing what constitutes an "x86 event" so maintainers understand the criteria without digging into the implementation.

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static inline bool check_leader_group(struct perf_event *leader, int flags)
{
return is_x86_event(leader) ? !!(leader->hw.flags & flags) : false;
}

static inline bool is_branch_counters_group(struct perf_event *event)
{
return event->group_leader->hw.flags & PERF_X86_EVENT_BRANCH_COUNTERS;
return check_leader_group(event->group_leader, PERF_X86_EVENT_BRANCH_COUNTERS);
}

struct amd_nb {
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