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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-12 10:05:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-12 10:05:24 -0700
commit20e2aa812620439d010a3f78ba4e05bc0b3e2861 (patch)
tree54b62d23640c85b60900e614b73e1edab71bb909 /kernel
parent652fa53caa01dbfdef1b8c5997767e284ac21a5c (diff)
parentd3296fb372bf7497b0e5d0478c4e7a677ec6f6e9 (diff)
Merge tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner: "Three fixes/updates for perf: - Fix the perf event cgroup tracking which tries to track the cgroup even for disabled events. - Add Ice Lake server support for uncore events - Disable pagefaults when retrieving the physical address in the sampling code" * tag 'perf-urgent-2020-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Disable page faults when getting phys address perf/x86/intel/uncore: Add Ice Lake server uncore support perf/cgroup: Correct indirection in perf_less_group_idx() perf/core: Fix event cgroup tracking
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c82
1 files changed, 51 insertions, 31 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 55e44417f66d..bc9b98a9af9a 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -983,16 +983,10 @@ perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
event->shadow_ctx_time = now - t->timestamp;
}
-/*
- * Update cpuctx->cgrp so that it is set when first cgroup event is added and
- * cleared when last cgroup event is removed.
- */
static inline void
-list_update_cgroup_event(struct perf_event *event,
- struct perf_event_context *ctx, bool add)
+perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
{
struct perf_cpu_context *cpuctx;
- struct list_head *cpuctx_entry;
if (!is_cgroup_event(event))
return;
@@ -1009,28 +1003,41 @@ list_update_cgroup_event(struct perf_event *event,
* because if the first would mismatch, the second would not try again
* and we would leave cpuctx->cgrp unset.
*/
- if (add && !cpuctx->cgrp) {
+ if (ctx->is_active && !cpuctx->cgrp) {
struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
cpuctx->cgrp = cgrp;
}
- if (add && ctx->nr_cgroups++)
+ if (ctx->nr_cgroups++)
return;
- else if (!add && --ctx->nr_cgroups)
+
+ list_add(&cpuctx->cgrp_cpuctx_entry,
+ per_cpu_ptr(&cgrp_cpuctx_list, event->cpu));
+}
+
+static inline void
+perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
+{
+ struct perf_cpu_context *cpuctx;
+
+ if (!is_cgroup_event(event))
+ return;
+
+ /*
+ * Because cgroup events are always per-cpu events,
+ * @ctx == &cpuctx->ctx.
+ */
+ cpuctx = container_of(ctx, struct perf_cpu_context, ctx);
+
+ if (--ctx->nr_cgroups)
return;
- /* no cgroup running */
- if (!add)
+ if (ctx->is_active && cpuctx->cgrp)
cpuctx->cgrp = NULL;
- cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
- if (add)
- list_add(cpuctx_entry,
- per_cpu_ptr(&cgrp_cpuctx_list, event->cpu));
- else
- list_del(cpuctx_entry);
+ list_del(&cpuctx->cgrp_cpuctx_entry);
}
#else /* !CONFIG_CGROUP_PERF */
@@ -1096,11 +1103,14 @@ static inline u64 perf_cgroup_event_time(struct perf_event *event)
}
static inline void
-list_update_cgroup_event(struct perf_event *event,
- struct perf_event_context *ctx, bool add)
+perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
{
}
+static inline void
+perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
+{
+}
#endif
/*
@@ -1791,13 +1801,14 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx)
add_event_to_groups(event, ctx);
}
- list_update_cgroup_event(event, ctx, true);
-
list_add_rcu(&event->event_entry, &ctx->event_list);
ctx->nr_events++;
if (event->attr.inherit_stat)
ctx->nr_stat++;
+ if (event->state > PERF_EVENT_STATE_OFF)
+ perf_cgroup_event_enable(event, ctx);
+
ctx->generation++;
}
@@ -1976,8 +1987,6 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
event->attach_state &= ~PERF_ATTACH_CONTEXT;
- list_update_cgroup_event(event, ctx, false);
-
ctx->nr_events--;
if (event->attr.inherit_stat)
ctx->nr_stat--;
@@ -1994,8 +2003,10 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
* of error state is by explicit re-enabling
* of the event
*/
- if (event->state > PERF_EVENT_STATE_OFF)
+ if (event->state > PERF_EVENT_STATE_OFF) {
+ perf_cgroup_event_disable(event, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_OFF);
+ }
ctx->generation++;
}
@@ -2226,6 +2237,7 @@ event_sched_out(struct perf_event *event,
if (READ_ONCE(event->pending_disable) >= 0) {
WRITE_ONCE(event->pending_disable, -1);
+ perf_cgroup_event_disable(event, ctx);
state = PERF_EVENT_STATE_OFF;
}
perf_event_set_state(event, state);
@@ -2363,6 +2375,7 @@ static void __perf_event_disable(struct perf_event *event,
event_sched_out(event, cpuctx, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_OFF);
+ perf_cgroup_event_disable(event, ctx);
}
/*
@@ -2746,7 +2759,7 @@ static int __perf_install_in_context(void *info)
}
#ifdef CONFIG_CGROUP_PERF
- if (is_cgroup_event(event)) {
+ if (event->state > PERF_EVENT_STATE_OFF && is_cgroup_event(event)) {
/*
* If the current cgroup doesn't match the event's
* cgroup, we should not try to schedule it.
@@ -2906,6 +2919,7 @@ static void __perf_event_enable(struct perf_event *event,
ctx_sched_out(ctx, cpuctx, EVENT_TIME);
perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
+ perf_cgroup_event_enable(event, ctx);
if (!ctx->is_active)
return;
@@ -3508,7 +3522,8 @@ static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
static bool perf_less_group_idx(const void *l, const void *r)
{
- const struct perf_event *le = l, *re = r;
+ const struct perf_event *le = *(const struct perf_event **)l;
+ const struct perf_event *re = *(const struct perf_event **)r;
return le->group_index < re->group_index;
}
@@ -3616,8 +3631,10 @@ static int merge_sched_in(struct perf_event *event, void *data)
}
if (event->state == PERF_EVENT_STATE_INACTIVE) {
- if (event->attr.pinned)
+ if (event->attr.pinned) {
+ perf_cgroup_event_disable(event, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
+ }
*can_add_hw = 0;
ctx->rotate_necessary = 1;
@@ -6917,9 +6934,12 @@ static u64 perf_virt_to_phys(u64 virt)
* Try IRQ-safe __get_user_pages_fast first.
* If failed, leave phys_addr as 0.
*/
- if ((current->mm != NULL) &&
- (__get_user_pages_fast(virt, 1, 0, &p) == 1))
- phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
+ if (current->mm != NULL) {
+ pagefault_disable();
+ if (__get_user_pages_fast(virt, 1, 0, &p) == 1)
+ phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
+ pagefault_enable();
+ }
if (p)
put_page(p);