From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754087AbbFOIHP (ORCPT ); Mon, 15 Jun 2015 04:07:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44899 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753434AbbFOIHL (ORCPT ); Mon, 15 Jun 2015 04:07:11 -0400 Message-ID: <557E87A7.5010203@redhat.com> Date: Mon, 15 Jun 2015 16:07:03 +0800 From: Jason Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: "Michael S. Tsirkin" , Pankaj Gupta CC: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kaber@trash.net, davem@davemloft.net, vyasevic@redhat.com, bhutchings@solarflare.com, therbert@google.com, viro@zeniv.linux.org.uk Subject: Re: [PATCH net-next] Increase limit of macvtap queues References: <1434115828-9461-1-git-send-email-pagupta@redhat.com> <20150614103209-mutt-send-email-mst@redhat.com> In-Reply-To: <20150614103209-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/14/2015 04:42 PM, Michael S. Tsirkin wrote: > On Fri, Jun 12, 2015 at 07:00:28PM +0530, Pankaj Gupta wrote: >> Macvtap should be compatible with tuntap for maximum number >> of queues. '1059590254fa9dce9cafc4f07d1103dbec415e76' removes >> the limitation and increases number of queues in tuntap. >> Now, Its safe to increase number of queues in Macvtap as well. >> >> Signed-off-by: Pankaj Gupta > It's a good idea, but this might be a problem: > > static void macvtap_del_queues(struct net_device *dev) > { > struct macvlan_dev *vlan = netdev_priv(dev); > struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES]; > > ... > } > > by itself, this will use 2K on stack, which seems too much. > > You need to rework this function to use a linked list + list_move > instead of an array + list_del_init. Looks like even simpler, we can just do sock_put() inside list_for_each_entry_safe() loop. >> --- >> include/linux/if_macvlan.h | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h >> index 6f6929e..a4ccc31 100644 >> --- a/include/linux/if_macvlan.h >> +++ b/include/linux/if_macvlan.h >> @@ -29,7 +29,7 @@ struct macvtap_queue; >> * Maximum times a macvtap device can be opened. This can be used to >> * configure the number of receive queue, e.g. for multiqueue virtio. >> */ >> -#define MAX_MACVTAP_QUEUES 16 >> +#define MAX_MACVTAP_QUEUES 256 >> >> #define MACVLAN_MC_FILTER_BITS 8 >> #define MACVLAN_MC_FILTER_SZ (1 << MACVLAN_MC_FILTER_BITS) >> -- >> 1.7.1 > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html