[PATCH v3 01/15] perf: Remove redundant condition for AUX buffer size

From: Peter Zijlstra
Date: Tue Aug 12 2025 - 06:48:57 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

It is already checked whether the VMA size is the same as
nr_pages * PAGE_SIZE, so later checking both:

aux_size == vma_size && aux_size == nr_pages * PAGE_SIZE

is redundant. Remove the vma_size check as nr_pages is what is actually
used in the allocation function. That prepares for splitting out the buffer
allocation into seperate functions, so that only nr_pages needs to be
handed in.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20250811070620.389961756@xxxxxxxxxxxxx
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7043,7 +7043,7 @@ static int perf_mmap(struct file *file,
if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
goto aux_unlock;

- if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
+ if (aux_size != nr_pages * PAGE_SIZE)
goto aux_unlock;

/* already mapped with a different size */