Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752861AbbDMBUo (ORCPT ); Sun, 12 Apr 2015 21:20:44 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:29638 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752199AbbDMBUm convert rfc822-to-8bit (ORCPT ); Sun, 12 Apr 2015 21:20:42 -0400 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="90560538" From: Zhao Lei To: "'Boaz Harrosh'" , "'Christoph Hellwig'" CC: , "'Jan Kara'" , "'Jens Axboe'" , "'LKML'" References: <016d01d07380$fc37fc40$f4a7f4c0$@cn.fujitsu.com> <552A57F8.7020002@plexistor.com> <552A839C.4070101@plexistor.com> In-Reply-To: <552A839C.4070101@plexistor.com> Subject: RE: Regression caused by using node_to_bdi() Date: Mon, 13 Apr 2015 09:20:11 +0800 Message-ID: <025001d07587$fe059d80$fa10d880$@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Outlook 15.0 Thread-Index: AQGFPDSkCPVR9AeIZuOecNLBimqRUwJHSBkKAYlPTLWdwhImAA== Content-Language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2717 Lines: 90 Hi, Boaz > -----Original Message----- > From: Boaz Harrosh [mailto:boaz@plexistor.com] > Sent: Sunday, April 12, 2015 10:39 PM > To: Boaz Harrosh; Zhao Lei; 'Christoph Hellwig' > Cc: linux-fsdevel@vger.kernel.org; 'Jan Kara'; 'Jens Axboe'; 'LKML' > Subject: Re: Regression caused by using node_to_bdi() > > On 04/12/2015 02:33 PM, Boaz Harrosh wrote: > > On 04/10/2015 02:25 PM, Zhao Lei wrote: > >> Hi, Christoph Hellwig > >> > <> > >> > >> Is there some way to speed up it(inline, or some access some variant > >> in struct directly, ...)? > >> > > > > Christoph hi > > > > Both node_to_bdi() and sb_is_blkdev_sb() (and I_BDEV() && > > blk_get_backing_dev_info()) Are an exported function calls. > > > > Can we not make blockdev_superblock->s_bdi == NULL, and then > > optimize-out the call to sb_is_blkdev_sb() to only that case. > > Something like: > > > > --- > > > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index > > 32a8bbd..e0375e1 100644 > > --- a/fs/fs-writeback.c > > +++ b/fs/fs-writeback.c > > @@ -78,7 +78,7 @@ int writeback_in_progress(struct backing_dev_info > > *bdi) } EXPORT_SYMBOL(writeback_in_progress); > > > > -struct backing_dev_info *inode_to_bdi(struct inode *inode) > > +struct backing_dev_info *__inode_to_bdi(struct inode *inode) > > { > > struct super_block *sb; > > > > @@ -92,7 +92,7 @@ struct backing_dev_info *inode_to_bdi(struct inode > > *inode) #endif > > return sb->s_bdi; > > } > > -EXPORT_SYMBOL_GPL(inode_to_bdi); > > +EXPORT_SYMBOL_GPL(__inode_to_bdi); > > > > static inline struct inode *wb_inode(struct list_head *head) { diff > > --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > > index aff923a..7d172f5 100644 > > --- a/include/linux/backing-dev.h > > +++ b/include/linux/backing-dev.h > > @@ -107,7 +107,16 @@ struct backing_dev_info { #endif }; > > > > -struct backing_dev_info *inode_to_bdi(struct inode *inode); > > +struct backing_dev_info *__inode_to_bdi(struct inode *inode); > > + > > +static inline > > +struct backing_dev_info *inode_to_bdi(struct inode *inode) { > > + if (!inode || !inode->i_sb) > > + return __inode_to_bdi(inode); > > + > > + return inode->i_sb->s_bdi; > > +} > > > > This patch actually boots. Lei could you please test to see if it fixes your > slowness? > Thanks, I'll test this patch. Thanks Zhaolei > Thanks > Boaz > > > int __must_check bdi_init(struct backing_dev_info *bdi); void > > bdi_destroy(struct backing_dev_info *bdi); > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/