Re: [PATCH] (1/2) reverse mapping VM for 2.5.23 (rmap-13b)

Steven Cole
2002-06-19T19:06:42Z

On Wed, 2002-06-19 at 05:18, Craig Kulesa wrote:
>
>
> Where: http://loke.as.arizona.edu/~ckulesa/kernel/rmap-vm/
>
> This patch implements Rik van Riel's patches for a reverse mapping VM
> atop the 2.5.23 kernel infrastructure. The principal sticky bits in
> the port are correct interoperability with Andrew Morton's patches to
> cleanup and extend the writeback and readahead code, among other things.
> This patch reinstates Rik's (active, inactive dirty, inactive clean)
> LRU list logic with the rmap information used for proper selection of pages
> for eviction and better page aging. It seems to do a pretty good job even
> for a first porting attempt. A simple, indicative test suite on a 192 MB
> PII machine (loading a large image in GIMP, loading other applications,
> heightening memory load to moderate swapout, then going back and
> manipulating the original Gimp image to test page aging, then closing all
> apps to the starting configuration) shows the following:
>
> 2.5.22 vanilla:
> Total kernel swapouts during test = 29068 kB
> Total kernel swapins during test = 16480 kB
> Elapsed time for test: 141 seconds
>
> 2.5.23-rmap13b:
> Total kernel swapouts during test = 40696 kB
> Total kernel swapins during test = 380 kB
> Elapsed time for test: 133 seconds
>
> Although rmap's page_launder evicts a ton of pages under load, it seems to
> swap the 'right' pages, as it doesn't need to swap them back in again.
> This is a good sign. [recent 2.4-aa work pretty nicely too]
>
> Various details for the curious or bored:
>
> - Tested: UP, 16 MB < mem < 256 MB, x86 arch.
> Untested: SMP, highmem, other archs.
^^^
I tried to boot 2.5.23-rmap13b on a dual PIII without success.

Freeing unused kernel memory: 252k freed
hung here with CONFIG_SMP=y
Adding 1052248k swap on /dev/sda6. Priority:0 extents:1
Adding 1052248k swap on /dev/sdb1. Priority:0 extents:1

The above is the edited dmesg output from booting 2.5.23-rmap13b as an
UP kernel, which successfully booted on the same 2-way box.

Steven