From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Date: Fri, 29 Feb 2008 11:26:01 +0000 Subject: Re: [patch 2/6] mm: bdi: export BDI attributes in sysfs Message-Id: <20080229032601.4a9e31eb.akpm@linux-foundation.org> List-Id: References: <20080129154900.145303789@szeredi.hu> <20080129154948.823761079@szeredi.hu> In-Reply-To: <20080129154948.823761079@szeredi.hu> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Miklos Szeredi Cc: a.p.zijlstra@chello.nl, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Kay Sievers , Greg KH , Trond Myklebust , linux-ia64@vger.kernel.org On Tue, 29 Jan 2008 16:49:02 +0100 Miklos Szeredi wrote: > From: Peter Zijlstra > > Provide a place in sysfs (/sys/class/bdi) for the backing_dev_info > object. This allows us to see and set the various BDI specific > variables. > > In particular this properly exposes the read-ahead window for all > relevant users and /sys/block//queue/read_ahead_kb should be > deprecated. > > With patient help from Kay Sievers and Greg KH > > [mszeredi@suse.cz] > > - split off NFS and FUSE changes into separate patches > - document new sysfs attributes under Documentation/ABI > - do bdi_class_init as a core_initcall, otherwise the "default" BDI > won't be initialized > - remove bdi_init_fmt macro, it's not used very much please always provide diffstats. Documentation/ABI/testing/sysfs-class-bdi | 50 +++++++++++++ block/genhd.c | 3 include/linux/backing-dev.h | 8 ++ include/linux/writeback.h | 3 lib/percpu_counter.c | 1 mm/backing-dev.c | 108 ++++++++++++++++++++++++++++++ mm/page-writeback.c | 2 mm/readahead.c | 8 +- 8 files changed, 181 insertions(+), 2 deletions(-) would you believe this breaks ia64 allmodconfig, in the usual place: In file included from arch/ia64/ia32/sys_ia32.c:59: arch/ia64/ia32/ia32priv.h:342:1: warning: "SET_PERSONALITY" redefined In file included from include/linux/elf.h:7, from include/linux/module.h:14, from include/linux/device.h:21, from include/linux/backing-dev.h:15, from include/linux/nfs_fs_sb.h:5, from include/linux/nfs_fs.h:50, from arch/ia64/ia32/sys_ia32.c:35: include/asm/elf.h:180:1: warning: this is the location of the previous definition We keep on hitting stupid build errors in this area: ia64 and elf. It is obviously quite fragile. It would be nice to fix it properly. For now, the easy fix: --- a/include/linux/backing-dev.h~mm-bdi-export-bdi-attributes-in-sysfs-ia64-fix +++ a/include/linux/backing-dev.h @@ -12,10 +12,10 @@ #include #include #include -#include #include struct page; +struct device; /* * Bits in backing_dev_info.state