From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43852) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIjQD-0000pp-Qx for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:37:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UIjQC-000837-Ak for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:37:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25795) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIjQC-00082w-1W for qemu-devel@nongnu.org; Thu, 21 Mar 2013 13:37:00 -0400 From: Juan Quintela In-Reply-To: <1363881940-27505-9-git-send-email-owasserm@redhat.com> (Orit Wasserman's message of "Thu, 21 Mar 2013 18:05:39 +0200") References: <1363881940-27505-1-git-send-email-owasserm@redhat.com> <1363881940-27505-9-git-send-email-owasserm@redhat.com> Date: Thu, 21 Mar 2013 18:37:05 +0100 Message-ID: <87mwtwpsce.fsf@elfo.elfo> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH v3 8/9] Use qemu_put_buffer_no_copy for guest memory pages Reply-To: quintela@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Orit Wasserman Cc: pbonzini@redhat.com, chegu_vinod@hp.com, qemu-devel@nongnu.org, mst@redhat.com Orit Wasserman wrote: > This will remove an unneeded copy of guest memory pages. > For the page header and device state we still copy the data to the > static buffer the other option is to allocate the memory on demand > which is more expensive. > > Signed-off-by: Orit Wasserman > --- > arch_init.c | 2 +- > savevm.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch_init.c b/arch_init.c > index 98e2bc6..27b53eb 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -481,7 +481,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage) > /* XBZRLE overflow or normal page */ > if (bytes_sent == -1) { > bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE); > - qemu_put_buffer(f, p, TARGET_PAGE_SIZE); > + qemu_put_buffer_no_copy(f, p, TARGET_PAGE_SIZE); > bytes_sent += TARGET_PAGE_SIZE; > acct_info.norm_pages++; > } Once here, shouldn't we also change: block-migration.c::blk_send() qemu_put_buffer(f, blk->buf, BLOCK_SIZE); to nocopy? Again, this can be an additional patch. > diff --git a/savevm.c b/savevm.c > index fbfb9e3..50e8fb2 100644 > --- a/savevm.c > +++ b/savevm.c > @@ -634,7 +634,7 @@ void qemu_put_buffer_no_copy(QEMUFile *f, const uint8_t *buf, int size) > abort(); > } > > - f->iov[f->iovcnt].iov_base = f->buf + f->buf_index; > + f->iov[f->iovcnt].iov_base = (uint8_t *)buf; > f->iov[f->iovcnt++].iov_len = size; This bit should be in the previous patch, the error that I pointed? Later, Juan.