The following commit has been merged into the perf/core branch of tip:
Commit-ID: 0c8a4e4139adf09b27fb910edbc596ea2d31a5db
Gitweb: https://git.kernel.org/tip/0c8a4e4139adf09b27fb910edbc596ea2d31a5db
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Mon, 04 Nov 2024 14:39:25 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 04 Mar 2025 09:43:10 +01:00
perf/core: Further simplify perf_mmap()
Perform CSE and such.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Link: https://lore.kernel.org/r/20241104135519.354909594@xxxxxxxxxxxxx
---
kernel/events/core.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d1b04c8..4cd3494 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6698,9 +6698,18 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
return ret;
vma_size = vma->vm_end - vma->vm_start;
+ nr_pages = vma_size / PAGE_SIZE;
+
+ if (nr_pages > INT_MAX)
+ return -ENOMEM;
+
+ if (vma_size != PAGE_SIZE * nr_pages)
+ return -EINVAL;
+
+ user_extra = nr_pages;
if (vma->vm_pgoff == 0) {
- nr_pages = (vma_size / PAGE_SIZE) - 1;
+ nr_pages -= 1;
/*
* If we have rb pages ensure they're a power-of-two number, so we
@@ -6709,9 +6718,6 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
if (nr_pages != 0 && !is_power_of_2(nr_pages))
return -EINVAL;
- if (vma_size != PAGE_SIZE * (1 + nr_pages))
- return -EINVAL;
-
WARN_ON_ONCE(event->ctx->parent_ctx);
again:
mutex_lock(&event->mmap_mutex);
@@ -6735,8 +6741,6 @@ again:
rb = event->rb;
goto unlock;
}
-
- user_extra = nr_pages + 1;
} else {
/*
* AUX area mapping: if rb->aux_nr_pages != 0, it's already
@@ -6748,10 +6752,6 @@ again:
if (!event->rb)
return -EINVAL;
- nr_pages = vma_size / PAGE_SIZE;
- if (nr_pages > INT_MAX)
- return -ENOMEM;
-
mutex_lock(&event->mmap_mutex);
ret = -EINVAL;
@@ -6795,7 +6795,6 @@ again:
}
atomic_set(&rb->aux_mmap_count, 1);
- user_extra = nr_pages;
}
user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
|