Re: [patch] rewrite rd

2008-01-14 Thread Jens Axboe
On Mon, Jan 14 2008, Matthew Wilcox wrote: > On Tue, Dec 04, 2007 at 05:26:28AM +0100, Nick Piggin wrote: > > +static void copy_to_brd(struct brd_device *brd, const void *src, > > + sector_t sector, size_t n) > > +{ > > + struct page *page; > > + void *dst; > > + unsigned in

Re: [patch] rewrite rd

2008-01-14 Thread Matthew Wilcox
On Tue, Dec 04, 2007 at 05:26:28AM +0100, Nick Piggin wrote: > +static void copy_to_brd(struct brd_device *brd, const void *src, > + sector_t sector, size_t n) > +{ > + struct page *page; > + void *dst; > + unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_

Re: [patch] rewrite rd

2007-12-04 Thread Rob Landley
On Tuesday 04 December 2007 03:29:40 Nick Piggin wrote: > On Tue, Dec 04, 2007 at 01:55:17AM -0600, Rob Landley wrote: > > On Monday 03 December 2007 22:26:28 Nick Piggin wrote: > > > There is one slight downside -- direct block device access and > > > filesystem metadata access goes through an ext

Re: [patch] rewrite rd

2007-12-04 Thread Nick Piggin
On Tue, Dec 04, 2007 at 10:54:51AM +0100, Christian Borntraeger wrote: > Am Dienstag, 4. Dezember 2007 schrieb Nick Piggin: > [...] > > There is one slight downside -- direct block device access and filesystem > > metadata access goes through an extra copy and gets stored in RAM twice. > > However,

Re: [patch] rewrite rd

2007-12-04 Thread Christian Borntraeger
Am Dienstag, 4. Dezember 2007 schrieb Nick Piggin: [...] > There is one slight downside -- direct block device access and filesystem > metadata access goes through an extra copy and gets stored in RAM twice. > However, this downside is only slight, because the real buffercache of the > device is no

Re: [patch] rewrite rd

2007-12-04 Thread Nick Piggin
On Tue, Dec 04, 2007 at 01:55:17AM -0600, Rob Landley wrote: > On Monday 03 December 2007 22:26:28 Nick Piggin wrote: > > There is one slight downside -- direct block device access and filesystem > > metadata access goes through an extra copy and gets stored in RAM twice. > > However, this downside

Re: [patch] rewrite rd

2007-12-03 Thread Rob Landley
On Monday 03 December 2007 22:26:28 Nick Piggin wrote: > There is one slight downside -- direct block device access and filesystem > metadata access goes through an extra copy and gets stored in RAM twice. > However, this downside is only slight, because the real buffercache of the > device is now

Re: [patch] rewrite rd

2007-12-03 Thread Nick Piggin
On Tue, Dec 04, 2007 at 08:01:31AM +0100, Nick Piggin wrote: > Thanks for the review, I'll post an incremental patch in a sec. Index: linux-2.6/drivers/block/brd.c === --- linux-2.6.orig/drivers/block/brd.c +++ linux-2.6/drivers/blo

Re: [patch] rewrite rd

2007-12-03 Thread Nick Piggin
On Mon, Dec 03, 2007 at 10:29:03PM -0800, Andrew Morton wrote: > On Tue, 4 Dec 2007 05:26:28 +0100 Nick Piggin <[EMAIL PROTECTED]> wrote: > > > > There is one slight downside -- direct block device access and filesystem > > metadata access goes through an extra copy and gets stored in RAM twice. >

Re: [patch] rewrite rd

2007-12-03 Thread Andrew Morton
On Tue, 4 Dec 2007 05:26:28 +0100 Nick Piggin <[EMAIL PROTECTED]> wrote: > Hi, > > This is my proposal for a (hopefully) backwards compatible rd driver. > The motivation for me is not pressing, except that I have this code > sitting here that is either going to rot or get merged. I'm happy to > m

[patch] rewrite rd

2007-12-03 Thread Nick Piggin
Hi, This is my proposal for a (hopefully) backwards compatible rd driver. The motivation for me is not pressing, except that I have this code sitting here that is either going to rot or get merged. I'm happy to make myself maintainer of this code, but if any real block device driver writer would l