From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zheng Liu Subject: Re: [PATCH 04/29] jbd2: Reduce journal_head size Date: Thu, 11 Apr 2013 22:10:26 +0800 Message-ID: <20130411141026.GE3448@gmail.com> References: <1365456754-29373-1-git-send-email-jack@suse.cz> <1365456754-29373-5-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ted Tso , linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from mail-pb0-f43.google.com ([209.85.160.43]:43963 "EHLO mail-pb0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752764Ab3DKNx2 (ORCPT ); Thu, 11 Apr 2013 09:53:28 -0400 Received: by mail-pb0-f43.google.com with SMTP id md4so874358pbc.30 for ; Thu, 11 Apr 2013 06:53:28 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1365456754-29373-5-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Apr 08, 2013 at 11:32:09PM +0200, Jan Kara wrote: > Remove unused t_cow_tid field (ext4 copy-on-write support doesn't seem > to be happening) and change b_modified and b_jlist to bitfields thus > saving 8 bytes in the structure. > > Signed-off-by: Jan Kara Reviewed-by: Zheng Liu Regards, - Zheng > --- > include/linux/journal-head.h | 11 ++--------- > 1 files changed, 2 insertions(+), 9 deletions(-) > > diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h > index c18b46f..13a3da2 100644 > --- a/include/linux/journal-head.h > +++ b/include/linux/journal-head.h > @@ -31,21 +31,14 @@ struct journal_head { > /* > * Journalling list for this buffer [jbd_lock_bh_state()] > */ > - unsigned b_jlist; > + unsigned b_jlist:4; > > /* > * This flag signals the buffer has been modified by > * the currently running transaction > * [jbd_lock_bh_state()] > */ > - unsigned b_modified; > - > - /* > - * This feild tracks the last transaction id in which this buffer > - * has been cowed > - * [jbd_lock_bh_state()] > - */ > - tid_t b_cow_tid; > + unsigned b_modified:1; > > /* > * Copy of the buffer data frozen for writing to the log. > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html