From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: [PATCH 8/9] kvm: qemu: Drop the mutex while reading from tapfd Date: Fri, 25 Jul 2008 02:33:00 +0300 Message-ID: <4889112C.3050704@qumranet.com> References: <1216899979-32532-1-git-send-email-markmc@redhat.com> <1216899979-32532-2-git-send-email-markmc@redhat.com> <1216899979-32532-3-git-send-email-markmc@redhat.com> <1216899979-32532-4-git-send-email-markmc@redhat.com> <1216899979-32532-5-git-send-email-markmc@redhat.com> <1216899979-32532-6-git-send-email-markmc@redhat.com> <1216899979-32532-7-git-send-email-markmc@redhat.com> <1216899979-32532-8-git-send-email-markmc@redhat.com> <1216899979-32532-9-git-send-email-markmc@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Herbert Xu , Rusty Russell To: Mark McLoughlin Return-path: Received: from il.qumranet.com ([212.179.150.194]:44098 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756439AbYGXXeh (ORCPT ); Thu, 24 Jul 2008 19:34:37 -0400 In-Reply-To: <1216899979-32532-9-git-send-email-markmc@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Mark McLoughlin wrote: > The idea here is that with GSO, packets are much larger > and we can allow the vcpu threads to e.g. process irq > acks during the window where we're reading these > packets from the tapfd. > > Signed-off-by: Mark McLoughlin > --- > qemu/vl.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/qemu/vl.c b/qemu/vl.c > index efdaafd..de92848 100644 > --- a/qemu/vl.c > +++ b/qemu/vl.c > @@ -4281,7 +4281,9 @@ static void tap_send(void *opaque) > sbuf.buf = s->buf; > s->size = getmsg(s->fd, NULL, &sbuf, &f) >=0 ? sbuf.len : -1; > #else > Maybe do it only when GSO is actually used by the guest/tap. Otherwise it can cause some ctx trashing right? > + kvm_sleep_begin(); > s->size = read(s->fd, s->buf, sizeof(s->buf)); > + kvm_sleep_end(); > #endif > > if (s->size == -1 && errno == EINTR) >