From mboxrd@z Thu Jan 1 00:00:00 1970 X-GM-THRID: 6210549354962354176 X-Received: by 10.107.136.19 with SMTP id k19mr15006738iod.5.1446007589059; Tue, 27 Oct 2015 21:46:29 -0700 (PDT) X-BeenThere: outreachy-kernel@googlegroups.com Received: by 10.182.73.198 with SMTP id n6ls2098218obv.16.gmail; Tue, 27 Oct 2015 21:46:28 -0700 (PDT) X-Received: by 10.182.236.4 with SMTP id uq4mr16045306obc.3.1446007588592; Tue, 27 Oct 2015 21:46:28 -0700 (PDT) Return-Path: Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by gmr-mx.google.com with ESMTPS id fa8si4639632pab.1.2015.10.27.21.46.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Oct 2015 21:46:28 -0700 (PDT) Received-SPF: pass (google.com: domain of gregkh@linuxfoundation.org designates 140.211.169.12 as permitted sender) client-ip=140.211.169.12; Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of gregkh@linuxfoundation.org designates 140.211.169.12 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Received: from localhost (unknown [58.123.138.250]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 6A8E489F; Wed, 28 Oct 2015 04:46:27 +0000 (UTC) Date: Wed, 28 Oct 2015 13:46:25 +0900 From: Greg KH To: Ksenija Stanojevic Cc: outreachy-kernel Subject: Re: [Outreachy kernel] [PATCH] Staging: comedi: Use rwsemaphore Message-ID: <20151028044625.GA6015@kroah.com> References: <1446006196-6294-1-git-send-email-ksenija.stanojevic@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1446006196-6294-1-git-send-email-ksenija.stanojevic@gmail.com> User-Agent: Mutt/1.5.24 (2015-08-30) On Tue, Oct 27, 2015 at 09:23:16PM -0700, Ksenija Stanojevic wrote: > Functions that use semaphore for locking are divided into read/write > functions, so use locking mechanism that provides similar semantics. > > Signed-off-by: Ksenija Stanojevic Unless you can measure the speed differences by switching to such a lock, never switch to such a lock as they are much more complex and can actually cause things to go _slower_. So I can't take this patch unless you have measureable benchmark numbers. thanks, greg k-h