From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 7B1822E7658 for ; Tue, 12 Aug 2025 10:46:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754995576; cv=none; b=vGGhRF+egvzII/BeNoyEPBeb+Gvbh96TL/EoAEIapapkHgPdoNc+HvRkSIN6O8fNV/EWAaiYERTAvINMQByozkW08s2hSajHpnKk1sj9JgZ2vV9fuxbhicyNjkD1XDvSWWiq/owxdsHDTZkbXma434gRsr888j+YEYAtFWJ9VpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754995576; c=relaxed/simple; bh=6jXnp2rS7TSHsIuoRZxdD2f8WwXiq1oxKEXJqcaElw8=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=tTR3HhUyKCCraBlbJ9zYvGu5epkTFZhnzrQ0+ktb3yuzBK/qa4O/kue54WuazJN34pJxqJLy/fdwbs8xImav40yFyB0FawoLLTDNFxD7CXMsnbeYZ+2j7b5xaVdGlBmWHqUC/wl5VJzJVoOwYlp4u5CJRmDx/xZvvlgASsCo0VE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=VNx85/um; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VNx85/um" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=fJdG7PKCgL19h78JrV/TWKTJ1AopejIhDsc/rZOBL8E=; b=VNx85/umE5XxKIS0zpGhghKEVk q2sFaHPk+NRP8FTzScZQUM0F2WwWwbXbF2nYHVXHDIJ1ifa3Y/a24lupoLB3IIwapybYIkkRSBlEf DL6SbRhV+bT/g/pb8Rf95XJ5pZD43WX/rNpq7n3vDn+ZQCzi1b5u2HdLAvs8fUdXYr9PDR9MsRM15 p5wzvQfsPKvtlYvlfqc1KxaA095kvo3E/pa8e1frEjlwLRS9Ybksp50v84NTXBHOqaG8A8/HLbv0f soQwXifQeJbAwldqWHfNgIKcOsa+u6gd45M3/sAOpadQuIXqInEBKuxU5CLPK3JxdJIg/M7cLh4EE NWoCw09w==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1ulmWA-0000000FQZ9-1jPe; Tue, 12 Aug 2025 10:46:11 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 9E6EB300708; Tue, 12 Aug 2025 12:46:09 +0200 (CEST) Message-ID: <20250812104018.900078502@infradead.org> User-Agent: quilt/0.68 Date: Tue, 12 Aug 2025 12:39:03 +0200 From: Peter Zijlstra To: tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, torvalds@linuxfoundation.org, mingo@kernel.org, namhyung@kernel.org, acme@redhat.com, kees@kernel.org Subject: [PATCH v3 05/15] perf: Merge consecutive conditionals in perf_mmap() References: <20250812103858.234850285@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 if (cond) { A; } else { B; } if (cond) { C; } else { D; } into: if (cond) { A; C; } else { B; D; } Notably the conditions are not identical in form, but are equivalent. Suggested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7064,6 +7064,25 @@ static int perf_mmap(struct file *file, if (vma->vm_flags & VM_WRITE) flags |= RING_BUFFER_WRITABLE; + rb = rb_alloc(nr_pages, + event->attr.watermark ? event->attr.wakeup_watermark : 0, + event->cpu, flags); + + if (!rb) { + ret = -ENOMEM; + goto unlock; + } + + atomic_set(&rb->mmap_count, 1); + rb->mmap_user = get_current_user(); + rb->mmap_locked = extra; + + ring_buffer_attach(event, rb); + + perf_event_update_time(event); + perf_event_init_userpage(event); + perf_event_update_userpage(event); + ret = 0; } else { /* * AUX area mapping: if rb->aux_nr_pages != 0, it's already @@ -7120,29 +7139,7 @@ static int perf_mmap(struct file *file, if (vma->vm_flags & VM_WRITE) flags |= RING_BUFFER_WRITABLE; - } - if (!rb) { - rb = rb_alloc(nr_pages, - event->attr.watermark ? event->attr.wakeup_watermark : 0, - event->cpu, flags); - - if (!rb) { - ret = -ENOMEM; - goto unlock; - } - - atomic_set(&rb->mmap_count, 1); - rb->mmap_user = get_current_user(); - rb->mmap_locked = extra; - - ring_buffer_attach(event, rb); - - perf_event_update_time(event); - perf_event_init_userpage(event); - perf_event_update_userpage(event); - ret = 0; - } else { ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, event->attr.aux_watermark, flags); if (!ret) {