From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55862) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1buGg0-0001mL-Rb for qemu-devel@nongnu.org; Wed, 12 Oct 2016 06:22:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1buGfy-0001mk-Rd for qemu-devel@nongnu.org; Wed, 12 Oct 2016 06:22:19 -0400 Date: Wed, 12 Oct 2016 12:22:07 +0200 From: Kevin Wolf Message-ID: <20161012102207.GF5544@noname.redhat.com> References: <1476031419-6805-1-git-send-email-mark.cave-ayland@ilande.co.uk> <1476031419-6805-2-git-send-email-mark.cave-ayland@ilande.co.uk> <97da94bb-e32c-8d9f-7309-ca4bef4bbe7c@redhat.com> <3fa3f1f8-2b7e-8b1f-1272-ff3b3647e0d3@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3fa3f1f8-2b7e-8b1f-1272-ff3b3647e0d3@redhat.com> Subject: Re: [Qemu-devel] [PATCH 1/2] dma-helpers: explicitly pass alignment into dma-helpers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow Cc: Mark Cave-Ayland , Eric Blake , keith.busch@intel.com, mreitz@redhat.com, pbonzini@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org Am 11.10.2016 um 17:47 hat John Snow geschrieben: > On 10/10/2016 03:23 PM, Mark Cave-Ayland wrote: > >On 10/10/16 17:34, Eric Blake wrote: > > > >>On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote: > >>>The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not > >>>necessarily the case for all platforms. Use this as the default alignment for > >>>all current callers. > >>> > >>>Signed-off-by: Mark Cave-Ayland > >>>--- > >> > >>>@@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret) > >>> return; > >>> } > >>> > >>>- if (dbs->iov.size & ~BDRV_SECTOR_MASK) { > >>>- qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK); > >>>+ if (dbs->iov.size & (dbs->align - 1)) { > >>>+ qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1)); > >> > >>Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size, > >>dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)? > >>Semantically it is the same, but the macros make it obvious what the > >>bit-twiddling is doing. > >> > >>Unless you think that needs a tweak, > >>Reviewed-by: Eric Blake > > > >I can't say I feel too strongly about it since there are plenty of other > >examples of this style in the codebase, so I'm happy to go with whatever > >John/Paolo are most happy with. > > > > > >ATB, > > > >Mark. > > > > I can't pretend I am consistent, but when in doubt use the macro. > Not worth a respin IMO, but I think this falls out of my > jurisdiction :) > > Acked-by: John Snow dma-helpers.c is officially unmaintained, and as the other patch is clearly IDE, I think the series should go through your tree. Kevin