From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:37041) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UPWtr-00044t-If for qemu-devel@nongnu.org; Tue, 09 Apr 2013 07:39:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UPWtq-0005cJ-79 for qemu-devel@nongnu.org; Tue, 09 Apr 2013 07:39:43 -0400 Received: from mail-qa0-f52.google.com ([209.85.216.52]:46363) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UPWtq-0005cF-2C for qemu-devel@nongnu.org; Tue, 09 Apr 2013 07:39:42 -0400 Received: by mail-qa0-f52.google.com with SMTP id bs12so1658702qab.18 for ; Tue, 09 Apr 2013 04:39:41 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <5163FDF6.1080600@redhat.com> Date: Tue, 09 Apr 2013 13:39:34 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1365420597-5506-1-git-send-email-pbonzini@redhat.com> <1365420597-5506-2-git-send-email-pbonzini@redhat.com> <87hajgdjmt.fsf@elfo.elfo> In-Reply-To: <87hajgdjmt.fsf@elfo.elfo> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/4] migration: set f->is_write and flush in add_to_iovec List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: quintela@redhat.com Cc: kwolf@redhat.com, owasserm@redhat.com, qemu-devel@nongnu.org Il 09/04/2013 13:32, Juan Quintela ha scritto: > Paolo Bonzini wrote: >> Signed-off-by: Paolo Bonzini >> --- >> savevm.c | 25 +++++++++---------------- >> 1 file changed, 9 insertions(+), 16 deletions(-) >> >> diff --git a/savevm.c b/savevm.c >> index b1d8988..c952c41 100644 >> --- a/savevm.c >> +++ b/savevm.c >> @@ -631,6 +631,11 @@ static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size) >> f->iov[f->iovcnt].iov_base = (uint8_t *)buf; >> f->iov[f->iovcnt++].iov_len = size; >> } >> + >> + f->is_write = 1; >> + if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { >> + qemu_fflush(f); >> + } >> } >> >> void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size) >> @@ -645,14 +650,8 @@ void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size) >> abort(); >> } >> >> - add_to_iovec(f, buf, size); >> - >> - f->is_write = 1; >> f->bytes_xfer += size; >> - >> - if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { >> - qemu_fflush(f); >> - } >> + add_to_iovec(f, buf, size); >> } >> >> void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) >> @@ -674,7 +673,6 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) >> if (l > size) >> l = size; >> memcpy(f->buf + f->buf_index, buf, l); >> - f->is_write = 1; >> f->buf_index += l; > > we increase buf_index > >> qemu_put_buffer_async(f, f->buf + (f->buf_index - l), l); > > and we call add_to_iovec() here inside. Notice the torture to get the > old buf_index value. > >> if (qemu_file_get_error(f)) { >> @@ -697,15 +695,10 @@ void qemu_put_byte(QEMUFile *f, int v) >> abort(); >> } >> >> - f->buf[f->buf_index++] = v; >> - f->is_write = 1; >> + f->buf[f->buf_index] = v; >> f->bytes_xfer++; >> - >> - add_to_iovec(f, f->buf + (f->buf_index - 1), 1); >> - >> - if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { >> - qemu_fflush(f); >> - } >> + add_to_iovec(f, f->buf + f->buf_index, 1); >> + f->buf_index++; > > And here, we call add_to_iovec() and then increase buf_index > > Is there any good reason for not being consistent? The reason is that I didn't want to switch qemu_put_buffer_async->add_to_iovec in this patch. I do it in the next one. > Once there, I think that moving the handling of buf_index to inside > add_to_iovec() looks like a good idea? add_to_iovec() is not called always with something from f->buf. But it is a good idea to move this handling of buf_index: if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { out of add_to_iovec. I do that in patch 4. Paolo