Re: [PATCH] rd: Use a private inode for backing storage

2007-10-22 Thread Chris Mason
On Sun, 21 Oct 2007 12:39:30 -0600 [EMAIL PROTECTED] (Eric W. Biederman) wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > > On Sunday 21 October 2007 18:23, Eric W. Biederman wrote: > >> Christian Borntraeger <[EMAIL PROTECTED]> writes: > > > >> Let me put it another way. Looking at /proc/sl

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Nick Piggin
On Monday 22 October 2007 04:39, Eric W. Biederman wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > On Sunday 21 October 2007 18:23, Eric W. Biederman wrote: > >> Christian Borntraeger <[EMAIL PROTECTED]> writes: > >> > >> Let me put it another way. Looking at /proc/slabinfo I can get > >> 37

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Nick Piggin
On Monday 22 October 2007 03:56, Eric W. Biederman wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > OK, I missed that you set the new inode's aops to the ramdisk_aops > > rather than the bd_inode. Which doesn't make a lot of sense because > > you just have a lot of useless aops there now. > > N

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Eric W. Biederman
Nick Piggin <[EMAIL PROTECTED]> writes: > On Sunday 21 October 2007 18:23, Eric W. Biederman wrote: >> Christian Borntraeger <[EMAIL PROTECTED]> writes: > >> Let me put it another way. Looking at /proc/slabinfo I can get >> 37 buffer_heads per page. I can allocate 10% of memory in >> buffer_head

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Eric W. Biederman
Nick Piggin <[EMAIL PROTECTED]> writes: > OK, I missed that you set the new inode's aops to the ramdisk_aops > rather than the bd_inode. Which doesn't make a lot of sense because > you just have a lot of useless aops there now. Not totally useless as you have mentioned they are accessed by the lr

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Nick Piggin
On Sunday 21 October 2007 18:23, Eric W. Biederman wrote: > Christian Borntraeger <[EMAIL PROTECTED]> writes: > Let me put it another way. Looking at /proc/slabinfo I can get > 37 buffer_heads per page. I can allocate 10% of memory in > buffer_heads before we start to reclaim them. So it requir

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Nick Piggin
On Sunday 21 October 2007 16:48, Eric W. Biederman wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > Yes it does. It is exactly breaking the coherency between block > > device and filesystem metadata coherency that Andrew cared about. > > Whether or not that matters, that is a much bigger concep

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Eric W. Biederman
Christian Borntraeger <[EMAIL PROTECTED]> writes: > Am Sonntag, 21. Oktober 2007 schrieb Eric W. Biederman: >> Nick. Reread the patch. The only thing your arguments have >> established for me is that this patch is not obviously correct. Which >> makes it ineligible for a back port. Frankly I s

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-21 Thread Christian Borntraeger
Am Sonntag, 21. Oktober 2007 schrieb Eric W. Biederman: > Nick. Reread the patch. The only thing your arguments have > established for me is that this patch is not obviously correct. Which > makes it ineligible for a back port. Frankly I suspect the whole > issue is to subtle and rare to make a

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-20 Thread Eric W. Biederman
Nick Piggin <[EMAIL PROTECTED]> writes: > Yes it does. It is exactly breaking the coherency between block > device and filesystem metadata coherency that Andrew cared about. > Whether or not that matters, that is a much bigger conceptual > change than simply using slightly more (reclaimable) memor

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-20 Thread Nick Piggin
On Sunday 21 October 2007 15:10, Eric W. Biederman wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > On Saturday 20 October 2007 08:51, Eric W. Biederman wrote: > >> Currently the ramdisk tries to keep the block device page cache pages > >> from being marked clean and dropped from memory. That

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-20 Thread Eric W. Biederman
Nick Piggin <[EMAIL PROTECTED]> writes: > On Saturday 20 October 2007 08:51, Eric W. Biederman wrote: >> Currently the ramdisk tries to keep the block device page cache pages >> from being marked clean and dropped from memory. That fails for >> filesystems that use the buffer cache because the bu

Re: [PATCH] rd: Use a private inode for backing storage

2007-10-20 Thread Nick Piggin
On Saturday 20 October 2007 08:51, Eric W. Biederman wrote: > Currently the ramdisk tries to keep the block device page cache pages > from being marked clean and dropped from memory. That fails for > filesystems that use the buffer cache because the buffer cache is not > an ordinary buffer cache u

[PATCH] rd: Use a private inode for backing storage

2007-10-19 Thread Eric W. Biederman
Currently the ramdisk tries to keep the block device page cache pages from being marked clean and dropped from memory. That fails for filesystems that use the buffer cache because the buffer cache is not an ordinary buffer cache user and depends on the generic block device address space operation