Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753993Ab0LMTb4 (ORCPT ); Mon, 13 Dec 2010 14:31:56 -0500 Received: from smtp.microsoft.com ([131.107.115.215]:34922 "EHLO smtp.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753739Ab0LMTby convert rfc822-to-8bit (ORCPT ); Mon, 13 Dec 2010 14:31:54 -0500 From: Hank Janssen To: Greg KH CC: "gregkh@suse.de" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , "virtualization@lists.osdl.org" , Haiyang Zhang Subject: RE: [PATCH 1/1] hv: Use only one receive buffer and kmalloc on initialize Thread-Topic: [PATCH 1/1] hv: Use only one receive buffer and kmalloc on initialize Thread-Index: AQHLmu0aQ+svDewugEOir2/SbGE0mJOfORkA//+JKnA= Date: Mon, 13 Dec 2010 19:31:42 +0000 Message-ID: <8AFC7968D54FB448A30D8F38F259C5622C0BB71F@TK5EX14MBXC116.redmond.corp.microsoft.com> References: <1292262350-29001-1-git-send-email-hjanssen@microsoft.com> <20101213183448.GA11745@kroah.com> In-Reply-To: <20101213183448.GA11745@kroah.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [157.54.123.12] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1557 Lines: 43 > -----Original Message----- > From: Greg KH [mailto:greg@kroah.com] > Sent: Monday, December 13, 2010 10:35 AM > > --- > > drivers/staging/hv/hv_utils.c | 68 +++++++++++++++++++------------------ > --- > > 1 files changed, 32 insertions(+), 36 deletions(-) > > > > diff --git a/drivers/staging/hv/hv_utils.c > > b/drivers/staging/hv/hv_utils.c index 53e1e29..4ed4ab8 100644 > > --- a/drivers/staging/hv/hv_utils.c > > +++ b/drivers/staging/hv/hv_utils.c > > @@ -38,12 +38,15 @@ > > #include "vmbus_api.h" > > #include "utils.h" > > > > +/* > > + * Buffer used to receive packets from Hyper-V */ static u8 > > +*chan_buf; > > One buffer is nicer, yes, but what's controlling access to this buffer? > You use it in multiple functions, and what's to say those functions can't be > called at the same time on different cpus? So, shouldn't you either have > some locking for access to the buffer, or have a per-function buffer instead? > > And if you have a per-function buffer, again, you might need to control > access to it as the functions could be called multiple times at the same time, > right? > The current versions of Hyper-V support interrupt handling on CPU0 only. I can make multiple buffers per channel, but because of Hyper-V implementation It does not really make a difference. Hank. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/