Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-26 Thread William Lee Irwin III
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: >>> Dirty page accounting/limiting doesn't work for nonlinear mappings, so >>> for non-ram backed filesystems emulate with linear mappings. This >>> retains ABI compatibility with previous kernels at minimal code cost. >>> All known users

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-26 Thread William Lee Irwin III
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: Dirty page accounting/limiting doesn't work for nonlinear mappings, so for non-ram backed filesystems emulate with linear mappings. This retains ABI compatibility with previous kernels at minimal code cost. All known users of nonlinear

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Peter Zijlstra
On Sun, 2007-03-25 at 16:00 -0800, Andrew Morton wrote: > On Sat, 24 Mar 2007 23:09:19 +0100 Miklos Szeredi <[EMAIL PROTECTED]> wrote: > > > Dirty page accounting/limiting doesn't work for nonlinear mappings, > > Doesn't it? iirc the problem is that we don't correctly re-clean the ptes > while

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Andrew Morton
On Sat, 24 Mar 2007 23:09:19 +0100 Miklos Szeredi <[EMAIL PROTECTED]> wrote: > Dirty page accounting/limiting doesn't work for nonlinear mappings, Doesn't it? iirc the problem is that we don't correctly re-clean the ptes while starting writeout. And the dirty-page accounting is in fact correct

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Matt Mackall
On Sun, Mar 25, 2007 at 02:12:32PM +0200, Peter Zijlstra wrote: > On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: > > From: Miklos Szeredi <[EMAIL PROTECTED]> > > > > Dirty page accounting/limiting doesn't work for nonlinear mappings, so > > for non-ram backed filesystems emulate with

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Peter Zijlstra
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: > From: Miklos Szeredi <[EMAIL PROTECTED]> > > Dirty page accounting/limiting doesn't work for nonlinear mappings, so > for non-ram backed filesystems emulate with linear mappings. This > retains ABI compatibility with previous kernels at

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Peter Zijlstra
On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: From: Miklos Szeredi [EMAIL PROTECTED] Dirty page accounting/limiting doesn't work for nonlinear mappings, so for non-ram backed filesystems emulate with linear mappings. This retains ABI compatibility with previous kernels at minimal

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Matt Mackall
On Sun, Mar 25, 2007 at 02:12:32PM +0200, Peter Zijlstra wrote: On Sat, 2007-03-24 at 23:09 +0100, Miklos Szeredi wrote: From: Miklos Szeredi [EMAIL PROTECTED] Dirty page accounting/limiting doesn't work for nonlinear mappings, so for non-ram backed filesystems emulate with linear

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Andrew Morton
On Sat, 24 Mar 2007 23:09:19 +0100 Miklos Szeredi [EMAIL PROTECTED] wrote: Dirty page accounting/limiting doesn't work for nonlinear mappings, Doesn't it? iirc the problem is that we don't correctly re-clean the ptes while starting writeout. And the dirty-page accounting is in fact correct

Re: [patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-25 Thread Peter Zijlstra
On Sun, 2007-03-25 at 16:00 -0800, Andrew Morton wrote: On Sat, 24 Mar 2007 23:09:19 +0100 Miklos Szeredi [EMAIL PROTECTED] wrote: Dirty page accounting/limiting doesn't work for nonlinear mappings, Doesn't it? iirc the problem is that we don't correctly re-clean the ptes while starting

[patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-24 Thread Miklos Szeredi
From: Miklos Szeredi <[EMAIL PROTECTED]> Dirty page accounting/limiting doesn't work for nonlinear mappings, so for non-ram backed filesystems emulate with linear mappings. This retains ABI compatibility with previous kernels at minimal code cost. All known users of nonlinear mappings actually

[patch 2/3] only allow nonlinear vmas for ram backed filesystems

2007-03-24 Thread Miklos Szeredi
From: Miklos Szeredi [EMAIL PROTECTED] Dirty page accounting/limiting doesn't work for nonlinear mappings, so for non-ram backed filesystems emulate with linear mappings. This retains ABI compatibility with previous kernels at minimal code cost. All known users of nonlinear mappings actually