Comment 17 for bug 376896

Well, 2.6.34-r1 is out and it contains patch under question. I've managed to try in on a testbox and compare with 2.6.32-gentoo-r3 on a x86_64 machine with 4G of ram

The file list is clean. After restart, adding a single 8G file causes ZERO swapping, and the system stays responsive. With 2.6.32 swapping occurs instantly when free memory reaches it's minimum and kswapd begins reclaiming pages. The system becomes sluggish, mouse cursor jumps.
Overall hashing speed with the new kernel is very stable - 57Mb/s on my old SATA drive. With 2.6.32, hashing speed is also very stable until kswapd steps in - after that, hashing speed drops to ~50Mb/sec and oscillates around it.
When hashing thread is finished, new kernel still shows ZERO swap usage, whereas 2.6.32 shows this:
$ free
             total used free shared buffers cached
Mem: 4055264 4022896 32368 0 2952 3824016
-/+ buffers/cache: 195928 3859336
Swap: 2008084 122796 1885288

So, this post is not a confirmation of a problem resolution, more testing is needed, and probably not until the patchset is backported on 2.6.33 series. Or, maybe, not until 2.6.34 is stable.