From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41839) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uwvqa-0001qk-JG for qemu-devel@nongnu.org; Wed, 10 Jul 2013 10:58:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UwvqZ-0003y5-Ag for qemu-devel@nongnu.org; Wed, 10 Jul 2013 10:58:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28622) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UwvqZ-0003xw-11 for qemu-devel@nongnu.org; Wed, 10 Jul 2013 10:58:23 -0400 Date: Wed, 10 Jul 2013 16:58:16 +0200 From: Kevin Wolf Message-ID: <20130710145816.GX3898@dhcp-200-207.str.redhat.com> References: <1372338695-411-1-git-send-email-pl@kamp.de> <1372338695-411-11-git-send-email-pl@kamp.de> <20130710113313.GK3898@dhcp-200-207.str.redhat.com> <51DD69F8.3050305@kamp.de> <20130710142807.GQ3898@dhcp-200-207.str.redhat.com> <51DD7472.9020303@kamp.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51DD7472.9020303@kamp.de> Subject: Re: [Qemu-devel] [PATCHv2 10/11] iscsi: ignore aio_discard if unsupported List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: pbonzini@redhat.com, ronniesahlberg@gmail.com, qemu-devel@nongnu.org, stefanha@redhat.com Am 10.07.2013 um 16:49 hat Peter Lieven geschrieben: > Am 10.07.2013 16:28, schrieb Kevin Wolf: > > Am 10.07.2013 um 16:04 hat Peter Lieven geschrieben: > >> Am 10.07.2013 13:33, schrieb Kevin Wolf: > >>> Am 27.06.2013 um 15:11 hat Peter Lieven geschrieben: > >>>> if the target does not support UNMAP or the request > >>>> is too big silently ignore the discard request. > >>>> > >>>> Signed-off-by: Peter Lieven > >>> Why not loop for the "too big" case? You can probably use the same logic > >>> for unmapping the whole device in .bdrv_create and here. > >> right, but looping in an aio function seemed not so trivial to me. > >> it seems more and more obvious to me that the best would be to change > >> all the remaining aio routines to co routines. > > The pattern for AIO functions is that the real work of submitting > > requests is done in the AIO callback, and it submits new AIO requests > > calling back into the same callback as long as acb->remaining_secs > 0 > > (or something like that). > > > > You can still see that kind of thing alive in qed_aio_next_io(), (most > > of?) the rest is converted to coroutines because it makes the code look > > nicer. > would you agree if I leave the easy version in just to fix the potential > problems if iscsi_aio_discard is called with too high nb_sectors or > on a storage where UNMAP is unsupported. > > I will add a TODO with the comment that the limit of iscsi->max_unmap should > be replaced by a loop once the routine is replaced by a coroutine? Meh, another pony I don't get... ;-) Leaving a TODO comment for now is okay with me. > >> in this case i could add the too big logic in iscsi_co_discard and simply call > >> it from iscsi_co_write_zeroes. > > I think that would be the nicest solution. > I promised to take care of this for 1.7.0 latest. Okay, thanks. Kevin