From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:56750) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TLJfk-0003Po-6a for qemu-devel@nongnu.org; Mon, 08 Oct 2012 16:11:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TLJfj-0003rb-23 for qemu-devel@nongnu.org; Mon, 08 Oct 2012 16:11:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62295) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TLJfi-0003rX-Oo for qemu-devel@nongnu.org; Mon, 08 Oct 2012 16:11:26 -0400 Message-ID: <507333C8.5020408@redhat.com> Date: Mon, 08 Oct 2012 22:12:56 +0200 From: Hans de Goede MIME-Version: 1.0 References: <5073083C.1060201@siemens.com> In-Reply-To: <5073083C.1060201@siemens.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] chardev: Use timer instead of bottom-half to postpone open event List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: qemu-devel Hi, Funny that you ping about this just now, as I wanted to work on this today, but sofar I did not get around to it. Maybe tonight I will :) Long story short: Yes I've some remarks, but I pan to fix those myself and then merge it in my tree. I'll get back to you when this is done. Regards, Hans On 10/08/2012 07:07 PM, Jan Kiszka wrote: > As the block layer may decide to flush bottom-halfs while the machine is > still initializing (e.g. to read geometry data from the disk), our > postponed open event may be processed before the last frontend > registered with a muxed chardev. Until the semantics of BHs have been > clarified, use an expired timer to achieve the same effect (suggested > by Paolo Bonzini). > > Signed-off-by: Jan Kiszka > --- > > This obsoletes the versatilepb hack. > > qemu-char.c | 13 +++++++------ > qemu-char.h | 2 +- > 2 files changed, 8 insertions(+), 7 deletions(-) > > diff --git a/qemu-char.c b/qemu-char.c > index f9ee2f0..fb4e3dc 100644 > --- a/qemu-char.c > +++ b/qemu-char.c > @@ -123,19 +123,20 @@ void qemu_chr_be_event(CharDriverState *s, int event) > s->chr_event(s->handler_opaque, event); > } > > -static void qemu_chr_generic_open_bh(void *opaque) > +static void qemu_chr_fire_open_event(void *opaque) > { > CharDriverState *s = opaque; > qemu_chr_be_event(s, CHR_EVENT_OPENED); > - qemu_bh_delete(s->bh); > - s->bh = NULL; > + qemu_free_timer(s->open_timer); > + s->open_timer = NULL; > } > > void qemu_chr_generic_open(CharDriverState *s) > { > - if (s->bh == NULL) { > - s->bh = qemu_bh_new(qemu_chr_generic_open_bh, s); > - qemu_bh_schedule(s->bh); > + if (s->open_timer == NULL) { > + s->open_timer = qemu_new_timer_ms(vm_clock, > + qemu_chr_fire_open_event, s); > + qemu_mod_timer(s->open_timer, qemu_get_clock_ms(vm_clock) - 1); > } > } > > diff --git a/qemu-char.h b/qemu-char.h > index 486644b..297dd98 100644 > --- a/qemu-char.h > +++ b/qemu-char.h > @@ -69,7 +69,7 @@ struct CharDriverState { > void (*chr_guest_open)(struct CharDriverState *chr); > void (*chr_guest_close)(struct CharDriverState *chr); > void *opaque; > - QEMUBH *bh; > + QEMUTimer *open_timer; > char *label; > char *filename; > int opened; >