Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-25 Thread William Lee Irwin III
On Wed, Jul 25, 2007 at 04:39:04PM +0200, Andrea Arcangeli wrote: > For the kernel stack btw, when alloc_pages(order=1) fails vmalloc > should be used and 4k stacks can be dropped. Nobody does dma from the > stack anymore these days IIRC (it doesn't work in all archs anyway). I have recent code

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-25 Thread Andrea Arcangeli
On Tue, Jul 24, 2007 at 08:20:11PM -0700, William Lee Irwin III wrote: > In any event, I've never been involved in a research project, though I didn't mean it was supposed to be research project in some University. But IIRC it was founded by what is defined as R in the income statement of a

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-25 Thread Andrea Arcangeli
On Tue, Jul 24, 2007 at 08:20:11PM -0700, William Lee Irwin III wrote: In any event, I've never been involved in a research project, though I didn't mean it was supposed to be research project in some University. But IIRC it was founded by what is defined as RD in the income statement of a

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-25 Thread William Lee Irwin III
On Wed, Jul 25, 2007 at 04:39:04PM +0200, Andrea Arcangeli wrote: For the kernel stack btw, when alloc_pages(order=1) fails vmalloc should be used and 4k stacks can be dropped. Nobody does dma from the stack anymore these days IIRC (it doesn't work in all archs anyway). I have recent code for

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-24 Thread William Lee Irwin III
On Wed, Jul 18, 2007 at 06:32:22AM -0700, William Lee Irwin III wrote: >> Actually I'd worked on what was called MPSS (Multiple Page Size Support) >> before I ever started on pgcl. Some large portion of the pgcl proposal >> as I presented it internally was to reduce the order of large page >>

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-24 Thread Andrea Arcangeli
On Wed, Jul 18, 2007 at 06:32:22AM -0700, William Lee Irwin III wrote: > Actually I'd worked on what was called MPSS (Multiple Page Size Support) > before I ever started on pgcl. Some large portion of the pgcl proposal > as I presented it internally was to reduce the order of large page >

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-24 Thread Andrea Arcangeli
On Wed, Jul 18, 2007 at 06:32:22AM -0700, William Lee Irwin III wrote: Actually I'd worked on what was called MPSS (Multiple Page Size Support) before I ever started on pgcl. Some large portion of the pgcl proposal as I presented it internally was to reduce the order of large page allocations

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-24 Thread William Lee Irwin III
On Wed, Jul 18, 2007 at 06:32:22AM -0700, William Lee Irwin III wrote: Actually I'd worked on what was called MPSS (Multiple Page Size Support) before I ever started on pgcl. Some large portion of the pgcl proposal as I presented it internally was to reduce the order of large page allocations

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Rene Herman
On 07/19/2007 01:50 AM, Andrea Arcangeli wrote: On Wed, Jul 18, 2007 at 06:34:20PM +0200, Rene Herman wrote: It says that highmem is not an issue due to no such thing as highmem even existing on the machines with support for larger hard pagesizes, but this wouldn't hold for soft pages. Sort

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Andrea Arcangeli
On Wed, Jul 18, 2007 at 06:34:20PM +0200, Rene Herman wrote: > It says that highmem is not an issue due to no such thing as highmem even > existing on the machines with support for larger hard pagesizes, but this > wouldn't hold for soft pages. Sort of went "damn" in an x86 context upon >

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Rene Herman
On 07/18/2007 03:32 PM, William Lee Irwin III wrote: On Tue, Jul 17, 2007 at 09:33:08PM +0200, Andrea Arcangeli wrote: kmalloced 4k naturally aligned object into userland). I wouldn't call it tail packing, it's more a fine-granular pagecache with the already available kmalloc granularities.

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread William Lee Irwin III
On Tue, Jul 17, 2007 at 10:47:37AM -0700, William Lee Irwin III wrote: >> You may rest assured that it's technically feasible. It's been done. >> The larger obstacles to all this are nontechnical. On Tue, Jul 17, 2007 at 09:33:08PM +0200, Andrea Arcangeli wrote: > Back then there was no variable

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread William Lee Irwin III
On Tue, Jul 17, 2007 at 10:47:37AM -0700, William Lee Irwin III wrote: You may rest assured that it's technically feasible. It's been done. The larger obstacles to all this are nontechnical. On Tue, Jul 17, 2007 at 09:33:08PM +0200, Andrea Arcangeli wrote: Back then there was no variable order

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Rene Herman
On 07/18/2007 03:32 PM, William Lee Irwin III wrote: On Tue, Jul 17, 2007 at 09:33:08PM +0200, Andrea Arcangeli wrote: kmalloced 4k naturally aligned object into userland). I wouldn't call it tail packing, it's more a fine-granular pagecache with the already available kmalloc granularities.

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Andrea Arcangeli
On Wed, Jul 18, 2007 at 06:34:20PM +0200, Rene Herman wrote: It says that highmem is not an issue due to no such thing as highmem even existing on the machines with support for larger hard pagesizes, but this wouldn't hold for soft pages. Sort of went damn in an x86 context upon reading

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-18 Thread Rene Herman
On 07/19/2007 01:50 AM, Andrea Arcangeli wrote: On Wed, Jul 18, 2007 at 06:34:20PM +0200, Rene Herman wrote: It says that highmem is not an issue due to no such thing as highmem even existing on the machines with support for larger hard pagesizes, but this wouldn't hold for soft pages. Sort

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-17 Thread Andrea Arcangeli
On Tue, Jul 17, 2007 at 10:47:37AM -0700, William Lee Irwin III wrote: > You may rest assured that it's technically feasible. It's been done. > The larger obstacles to all this are nontechnical. Back then there was no variable order page size proposal, no slub, generally nothing of that kind. I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-17 Thread William Lee Irwin III
On Sat, Jul 07, 2007 at 01:52:28AM +0200, Andrea Arcangeli wrote: > BTW, in a parallel thread (the thread where I've been suggested to > post this), Rik rightfully mentioned Bill once also tried to get this > working and basically asked for the differences. I don't know exactly > what Bill did, I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-17 Thread William Lee Irwin III
On Sat, Jul 07, 2007 at 01:52:28AM +0200, Andrea Arcangeli wrote: BTW, in a parallel thread (the thread where I've been suggested to post this), Rik rightfully mentioned Bill once also tried to get this working and basically asked for the differences. I don't know exactly what Bill did, I only

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-17 Thread Andrea Arcangeli
On Tue, Jul 17, 2007 at 10:47:37AM -0700, William Lee Irwin III wrote: You may rest assured that it's technically feasible. It's been done. The larger obstacles to all this are nontechnical. Back then there was no variable order page size proposal, no slub, generally nothing of that kind. I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-15 Thread David Chinner
On Fri, Jul 13, 2007 at 04:31:09PM +0200, Andrea Arcangeli wrote: > On Fri, Jul 13, 2007 at 05:13:08PM +1000, David Chinner wrote: > > Sure. Fundamentally, though, I think it is the wrong approach to > > take - it's a workaround for a big negative side effect of > > increasing page size. It

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-15 Thread David Chinner
On Fri, Jul 13, 2007 at 04:31:09PM +0200, Andrea Arcangeli wrote: On Fri, Jul 13, 2007 at 05:13:08PM +1000, David Chinner wrote: Sure. Fundamentally, though, I think it is the wrong approach to take - it's a workaround for a big negative side effect of increasing page size. It introduces

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread Andrea Arcangeli
On Fri, Jul 13, 2007 at 05:13:08PM +1000, David Chinner wrote: > Sure. Fundamentally, though, I think it is the wrong approach to > take - it's a workaround for a big negative side effect of > increasing page size. It introduces lots of complexity and > difficult-to-test corner cases; judging by

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread Dave Kleikamp
On Fri, 2007-07-13 at 17:13 +1000, David Chinner wrote: > On Thu, Jul 12, 2007 at 09:34:57AM -0700, Dave Hansen wrote: > > On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: > > > On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: > > > > That's crap. Just because a machine has

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread David Chinner
On Thu, Jul 12, 2007 at 09:34:57AM -0700, Dave Hansen wrote: > On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: > > On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: > > > That's crap. Just because a machine has lots of memory does not > > > make it OK to waste lots of

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread David Chinner
On Thu, Jul 12, 2007 at 09:34:57AM -0700, Dave Hansen wrote: On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: That's crap. Just because a machine has lots of memory does not make it OK to waste lots of memory.

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread Dave Kleikamp
On Fri, 2007-07-13 at 17:13 +1000, David Chinner wrote: On Thu, Jul 12, 2007 at 09:34:57AM -0700, Dave Hansen wrote: On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: That's crap. Just because a machine has lots of

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-13 Thread Andrea Arcangeli
On Fri, Jul 13, 2007 at 05:13:08PM +1000, David Chinner wrote: Sure. Fundamentally, though, I think it is the wrong approach to take - it's a workaround for a big negative side effect of increasing page size. It introduces lots of complexity and difficult-to-test corner cases; judging by the

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Thu, Jul 12, 2007 at 12:53:09PM -0500, Matt Mackall wrote: > On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: > > The original idea of having a software page size larger than a > > hardware page size, originated at SUSE by myself and Andi Kleen while > > helping AMD to design

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Matt Mackall
On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: > The original idea of having a software page size larger than a > hardware page size, originated at SUSE by myself and Andi Kleen while > helping AMD to design their amd64 cpu, Original? This was done on VAXen and in Mach ages

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Dave Hansen
On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: > On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: > > That's crap. Just because a machine has lots of memory does not > > make it OK to waste lots of memory. > > It's not just wasted, it lowers overhead all over the place.

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: > That's crap. Just because a machine has lots of memory does not > make it OK to waste lots of memory. It's not just wasted, it lowers overhead all over the place. Yes, the benefit of wasting less pagecache may largely outweight the

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread David Chinner
On Thu, Jul 12, 2007 at 01:14:36PM +0200, Andrea Arcangeli wrote: > On Thu, Jul 12, 2007 at 10:12:56AM +1000, David Chinner wrote: > > I need really large filesystems that contain both small and large files to > > work more efficiently on small boxes where we can't throw endless amounts of > > RAM

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Thu, Jul 12, 2007 at 10:12:56AM +1000, David Chinner wrote: > I need really large filesystems that contain both small and large files to > work more efficiently on small boxes where we can't throw endless amounts of > RAM and CPUs at the problem. Hence things like 64k page size are just not an

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Thu, Jul 12, 2007 at 10:12:56AM +1000, David Chinner wrote: I need really large filesystems that contain both small and large files to work more efficiently on small boxes where we can't throw endless amounts of RAM and CPUs at the problem. Hence things like 64k page size are just not an

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread David Chinner
On Thu, Jul 12, 2007 at 01:14:36PM +0200, Andrea Arcangeli wrote: On Thu, Jul 12, 2007 at 10:12:56AM +1000, David Chinner wrote: I need really large filesystems that contain both small and large files to work more efficiently on small boxes where we can't throw endless amounts of RAM and

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: That's crap. Just because a machine has lots of memory does not make it OK to waste lots of memory. It's not just wasted, it lowers overhead all over the place. Yes, the benefit of wasting less pagecache may largely outweight the

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Dave Hansen
On Thu, 2007-07-12 at 18:31 +0200, Andrea Arcangeli wrote: On Fri, Jul 13, 2007 at 12:44:49AM +1000, David Chinner wrote: That's crap. Just because a machine has lots of memory does not make it OK to waste lots of memory. It's not just wasted, it lowers overhead all over the place. Yes,

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Matt Mackall
On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: The original idea of having a software page size larger than a hardware page size, originated at SUSE by myself and Andi Kleen while helping AMD to design their amd64 cpu, Original? This was done on VAXen and in Mach ages ago.

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-12 Thread Andrea Arcangeli
On Thu, Jul 12, 2007 at 12:53:09PM -0500, Matt Mackall wrote: On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: The original idea of having a software page size larger than a hardware page size, originated at SUSE by myself and Andi Kleen while helping AMD to design their

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-11 Thread David Chinner
On Tue, Jul 10, 2007 at 12:11:48PM +0200, Andrea Arcangeli wrote: > On Mon, Jul 09, 2007 at 09:20:31AM +1000, David Chinner wrote: > > I think you've misunderstood why large block sizes are important to > > XFS. The major benefits to XFS of larger block size have almost > > nothing to do with

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-11 Thread David Chinner
On Tue, Jul 10, 2007 at 12:11:48PM +0200, Andrea Arcangeli wrote: On Mon, Jul 09, 2007 at 09:20:31AM +1000, David Chinner wrote: I think you've misunderstood why large block sizes are important to XFS. The major benefits to XFS of larger block size have almost nothing to do with data

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-10 Thread Andrea Arcangeli
On Mon, Jul 09, 2007 at 09:20:31AM +1000, David Chinner wrote: > I think you've misunderstood why large block sizes are important to > XFS. The major benefits to XFS of larger block size have almost > nothing to do with data layout or in memory indexing - it comes from > metadata btree's getting

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-10 Thread Andrea Arcangeli
On Mon, Jul 09, 2007 at 09:20:31AM +1000, David Chinner wrote: I think you've misunderstood why large block sizes are important to XFS. The major benefits to XFS of larger block size have almost nothing to do with data layout or in memory indexing - it comes from metadata btree's getting much

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-08 Thread David Chinner
On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: > The xfs developers for example want to enlarge their filesystem > blocksize (the filesystem blocksize has a tradeoff similar to the > PAGE_SIZE, the larger the faster the filesystem but more disk space is > potentially wasted), I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-08 Thread Andrea Arcangeli
On Sat, Jul 07, 2007 at 08:53:49PM +0200, Jan Engelhardt wrote: > > On Jul 7 2007 00:26, Andrea Arcangeli wrote: > >Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) > > I wonder what happens if the soft page size gets set to 2048 bytes :) Well the min allowed shift

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-08 Thread Andrea Arcangeli
On Sat, Jul 07, 2007 at 08:53:49PM +0200, Jan Engelhardt wrote: On Jul 7 2007 00:26, Andrea Arcangeli wrote: Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) I wonder what happens if the soft page size gets set to 2048 bytes :) Well the min allowed shift is 12 so you can't set

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-08 Thread David Chinner
On Sat, Jul 07, 2007 at 12:26:51AM +0200, Andrea Arcangeli wrote: The xfs developers for example want to enlarge their filesystem blocksize (the filesystem blocksize has a tradeoff similar to the PAGE_SIZE, the larger the faster the filesystem but more disk space is potentially wasted), I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Rik van Riel
Jan Engelhardt wrote: On Jul 7 2007 00:26, Andrea Arcangeli wrote: Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) I wonder what happens if the soft page size gets set to 2048 bytes :) That won't work, because the smallest granularity the x86 MMU supports is 4kB. -- Politics

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Jan Engelhardt
On Jul 7 2007 00:26, Andrea Arcangeli wrote: >Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) I wonder what happens if the soft page size gets set to 2048 bytes :) Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Andrea Arcangeli
On Sat, Jul 07, 2007 at 05:01:57PM +1000, Paul Mackerras wrote: > Andrea Arcangeli writes: > > > So my whole idea is to once and for all to decuple the size of the > > pte-entry (4k on x86/amd64) with the page allocator granularity. The > > HARD_PAGE_SHIFT will be 4k still, the common code

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Andrea Arcangeli
On Fri, Jul 06, 2007 at 06:47:01PM -0700, Badari Pulavarty wrote: > Hmm.. I didn't have any luck booting my machine with the patchset > (with 8k pagesize) :( > > It fails to find the partition table on my hard drive. I'm afraid I can't reproduce :( Best would be to track that code and see

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Paul Mackerras
Andrea Arcangeli writes: > So my whole idea is to once and for all to decuple the size of the > pte-entry (4k on x86/amd64) with the page allocator granularity. The > HARD_PAGE_SHIFT will be 4k still, the common code PAGE_SIZE will be > variable and configurable at compile time with

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Paul Mackerras
Andrea Arcangeli writes: So my whole idea is to once and for all to decuple the size of the pte-entry (4k on x86/amd64) with the page allocator granularity. The HARD_PAGE_SHIFT will be 4k still, the common code PAGE_SIZE will be variable and configurable at compile time with

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Andrea Arcangeli
On Fri, Jul 06, 2007 at 06:47:01PM -0700, Badari Pulavarty wrote: Hmm.. I didn't have any luck booting my machine with the patchset (with 8k pagesize) :( It fails to find the partition table on my hard drive. I'm afraid I can't reproduce :( Best would be to track that code and see what's

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Andrea Arcangeli
On Sat, Jul 07, 2007 at 05:01:57PM +1000, Paul Mackerras wrote: Andrea Arcangeli writes: So my whole idea is to once and for all to decuple the size of the pte-entry (4k on x86/amd64) with the page allocator granularity. The HARD_PAGE_SHIFT will be 4k still, the common code PAGE_SIZE will

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Jan Engelhardt
On Jul 7 2007 00:26, Andrea Arcangeli wrote: Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) I wonder what happens if the soft page size gets set to 2048 bytes :) Jan -- - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-07 Thread Rik van Riel
Jan Engelhardt wrote: On Jul 7 2007 00:26, Andrea Arcangeli wrote: Subject: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE) I wonder what happens if the soft page size gets set to 2048 bytes :) That won't work, because the smallest granularity the x86 MMU supports is 4kB. -- Politics

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Badari Pulavarty
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: .. > The following simple bench seems to run fine on one real hardware and > on kvm (a friend of mine failed so far to run it on his hardware > though, so perhaps some driver triggers some remaining bugs) when > booted as

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Badari Pulavarty
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: > Hello, > .. > > If you want to help/look here the patch: > > > http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.22-rc7/hard-page-size > Very interesting patch set. I really would like to support for it. I

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Andrea Arcangeli
On Fri, Jul 06, 2007 at 04:33:21PM -0700, Dave Hansen wrote: > The patch looks really interesting, it's just a little hard to parse > with all of the s/4096/PAGE_SIZE/ bits around. Those cleanups, along > with the s/PAGE_SIZE/HARD_PAGE_SIZE/ parts would be great in a > separated-out patch so that

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Dave Hansen
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: > for the hack week at opensuse (see http://idea.opensuse.org/) I've > been working on a new feature called CONFIG_PAGE_SHIFT. ... > If you want to help/look here the patch: > > >

RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Andrea Arcangeli
Hello, for the hack week at opensuse (see http://idea.opensuse.org/) I've been working on a new feature called CONFIG_PAGE_SHIFT. In the last few days while reading the topics of the VM summit I answered I disliked the dependency on defrag for reliable I/O and I suggested I had an alternative

RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Andrea Arcangeli
Hello, for the hack week at opensuse (see http://idea.opensuse.org/) I've been working on a new feature called CONFIG_PAGE_SHIFT. In the last few days while reading the topics of the VM summit I answered I disliked the dependency on defrag for reliable I/O and I suggested I had an alternative

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Dave Hansen
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: for the hack week at opensuse (see http://idea.opensuse.org/) I've been working on a new feature called CONFIG_PAGE_SHIFT. ... If you want to help/look here the patch:

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Andrea Arcangeli
On Fri, Jul 06, 2007 at 04:33:21PM -0700, Dave Hansen wrote: The patch looks really interesting, it's just a little hard to parse with all of the s/4096/PAGE_SIZE/ bits around. Those cleanups, along with the s/PAGE_SIZE/HARD_PAGE_SIZE/ parts would be great in a separated-out patch so that the

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Badari Pulavarty
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: Hello, .. If you want to help/look here the patch: http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.22-rc7/hard-page-size Very interesting patch set. I really would like to support for it. I would

Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)

2007-07-06 Thread Badari Pulavarty
On Sat, 2007-07-07 at 00:26 +0200, Andrea Arcangeli wrote: .. The following simple bench seems to run fine on one real hardware and on kvm (a friend of mine failed so far to run it on his hardware though, so perhaps some driver triggers some remaining bugs) when booted as