From nobody Sat Oct 4 09:37:52 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A31C730E82E; Mon, 18 Aug 2025 10:22:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512550; cv=none; b=AMxKjMt3UQVEmJ0XC5LCHhSfqW0BZKVqX+B+n3fx9RuasTMkHyrhmoT08PU4Iwo7TpQXKJCqDJrW64oxknjNOYHkdIoU9JYovyfA4zPiAzOOxl5pAIKcHpM13z4DYPvTkcaXzIrC9J0haaLTqq7epgKa2YY63Ib8DG2jqwsLCkI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512550; c=relaxed/simple; bh=DMAveFfvUN6deTQzFhsPJqtjPDXtZLWY51NmnFXoYuE=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=U3Q4+s2N7qRKDVy/1FRgvWwk0JwoMW4ZxJmEO1rFUKmrINjiF2JLbziV+ukam1ejp17fMTWPxqj7BzKuQvzFI/qu5QIZ0gxNjfR4EVptovE6C3dWqhQ+rXvVlCMkHdPIL4gXbZ4fMzN4UtNxRxVXIvoJZy9kzoe+OKObZjBGhRY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=J5l2rjqL; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=dKdxSWvU; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="J5l2rjqL"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dKdxSWvU" Date: Mon, 18 Aug 2025 10:22:25 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1755512547; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J9SjC7lUH+GkLlvOrY9vqVnXDja7uDl2cbhH+lMcz+k=; b=J5l2rjqLueCbqO9IiJCKWFJ9uk5fABSlh6HINqrY+uTBs2Zbpa2GbLhVgWMwMYTl7o2oGG yqhIx2FlQvwcRqpuKRWBty936XfEwG7HEx/68gCjGLpWqfYmVnaJccMGEBEESLHL+JjW94 +C0EroXtuNbONHL0hHDuTg0HiatNHhKVa2iIKRubdWkj6bK0aE7HOfhQdN170dlf2R3T6B ak8RIWxga8DkBd1KXYtZHGu+dSbpW8GzWQxRBY+OlnEOR1+NOitmlaS4IMtAD2YJAqYswi Ayrv3CNj7OCfA27P3qrnhQpKy4H4NLtC9ZhtxyfRsmwQk7YCPcquTKHDUeCqGw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1755512547; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J9SjC7lUH+GkLlvOrY9vqVnXDja7uDl2cbhH+lMcz+k=; b=dKdxSWvUL2vSHStj9QNKFfW8RtFjjGcaGT95yQinVMBU5Rn3gBJE3mWpzLxC4qFno0pqB+ DlB0ta21S8empPCQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Split out the AUX buffer allocation Cc: Thomas Gleixner , "Peter Zijlstra (Intel)" , Lorenzo Stoakes , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250812104019.494205648@infradead.org> References: <20250812104019.494205648@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175551254598.1420.9411382396633457171.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/core branch of tip: Commit-ID: 2aee37682391332d26c01e703170e0d9358c7252 Gitweb: https://git.kernel.org/tip/2aee37682391332d26c01e703170e0d93= 58c7252 Author: Peter Zijlstra AuthorDate: Tue, 12 Aug 2025 12:39:08 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 15 Aug 2025 13:13:00 +02:00 perf: Split out the AUX buffer allocation Move the AUX buffer allocation branch into its own function. Originally-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Lorenzo Stoakes Link: https://lore.kernel.org/r/20250812104019.494205648@infradead.org --- kernel/events/core.c | 144 ++++++++++++++++++++++-------------------- 1 file changed, 77 insertions(+), 67 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 5bbea81..e76afd9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6970,6 +6970,82 @@ static void perf_mmap_account(struct vm_area_struct = *vma, long user_extra, long=20 atomic64_add(extra, &vma->vm_mm->pinned_vm); } =20 +static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *ev= ent, + unsigned long nr_pages) +{ + long extra =3D 0, user_extra =3D nr_pages; + u64 aux_offset, aux_size; + struct perf_buffer *rb; + int ret, rb_flags =3D 0; + + rb =3D event->rb; + if (!rb) + return -EINVAL; + + guard(mutex)(&rb->aux_mutex); + + /* + * AUX area mapping: if rb->aux_nr_pages !=3D 0, it's already + * mapped, all subsequent mappings should have the same size + * and offset. Must be above the normal perf buffer. + */ + aux_offset =3D READ_ONCE(rb->user_page->aux_offset); + aux_size =3D READ_ONCE(rb->user_page->aux_size); + + if (aux_offset < perf_data_size(rb) + PAGE_SIZE) + return -EINVAL; + + if (aux_offset !=3D vma->vm_pgoff << PAGE_SHIFT) + return -EINVAL; + + /* already mapped with a different offset */ + if (rb_has_aux(rb) && rb->aux_pgoff !=3D vma->vm_pgoff) + return -EINVAL; + + if (aux_size !=3D nr_pages * PAGE_SIZE) + return -EINVAL; + + /* already mapped with a different size */ + if (rb_has_aux(rb) && rb->aux_nr_pages !=3D nr_pages) + return -EINVAL; + + if (!is_power_of_2(nr_pages)) + return -EINVAL; + + if (!atomic_inc_not_zero(&rb->mmap_count)) + return -EINVAL; + + if (rb_has_aux(rb)) { + atomic_inc(&rb->aux_mmap_count); + + } else { + if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) { + atomic_dec(&rb->mmap_count); + return -EPERM; + } + + WARN_ON(!rb && event->rb); + + if (vma->vm_flags & VM_WRITE) + rb_flags |=3D RING_BUFFER_WRITABLE; + + ret =3D rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, + event->attr.aux_watermark, rb_flags); + if (ret) { + atomic_dec(&rb->mmap_count); + return ret; + } + + atomic_set(&rb->aux_mmap_count, 1); + rb->aux_mmap_locked =3D extra; + } + + perf_mmap_account(vma, user_extra, extra); + atomic_inc(&event->mmap_count); + + return 0; +} + static int perf_mmap(struct file *file, struct vm_area_struct *vma) { struct perf_event *event =3D file->private_data; @@ -7088,73 +7164,7 @@ static int perf_mmap(struct file *file, struct vm_ar= ea_struct *vma) perf_mmap_account(vma, user_extra, extra); atomic_inc(&event->mmap_count); } else { - /* - * AUX area mapping: if rb->aux_nr_pages !=3D 0, it's already - * mapped, all subsequent mappings should have the same size - * and offset. Must be above the normal perf buffer. - */ - u64 aux_offset, aux_size; - - rb =3D event->rb; - if (!rb) - goto unlock; - - guard(mutex)(&rb->aux_mutex); - - aux_offset =3D READ_ONCE(rb->user_page->aux_offset); - aux_size =3D READ_ONCE(rb->user_page->aux_size); - - if (aux_offset < perf_data_size(rb) + PAGE_SIZE) - goto unlock; - - if (aux_offset !=3D vma->vm_pgoff << PAGE_SHIFT) - goto unlock; - - /* already mapped with a different offset */ - if (rb_has_aux(rb) && rb->aux_pgoff !=3D vma->vm_pgoff) - goto unlock; - - if (aux_size !=3D nr_pages * PAGE_SIZE) - goto unlock; - - /* already mapped with a different size */ - if (rb_has_aux(rb) && rb->aux_nr_pages !=3D nr_pages) - goto unlock; - - if (!is_power_of_2(nr_pages)) - goto unlock; - - if (!atomic_inc_not_zero(&rb->mmap_count)) - goto unlock; - - if (rb_has_aux(rb)) { - atomic_inc(&rb->aux_mmap_count); - ret =3D 0; - - } else { - if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) { - ret =3D -EPERM; - atomic_dec(&rb->mmap_count); - goto unlock; - } - - WARN_ON(!rb && event->rb); - - if (vma->vm_flags & VM_WRITE) - flags |=3D RING_BUFFER_WRITABLE; - - ret =3D rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, - event->attr.aux_watermark, flags); - if (ret) { - atomic_dec(&rb->mmap_count); - goto unlock; - } - - atomic_set(&rb->aux_mmap_count, 1); - rb->aux_mmap_locked =3D extra; - } - perf_mmap_account(vma, user_extra, extra); - atomic_inc(&event->mmap_count); + ret =3D perf_mmap_aux(vma, event, nr_pages); } =20 unlock: