Messages in this thread | | | Date | Fri, 14 Jan 2005 14:55:27 +0100 (CET) | From | Tim Schmielau <> | Subject | swapspace layout improvements advocacy |
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On Wed, 12 Jan 2005, Andrew Morton wrote:
> Our current way of allocating swap can cause us to end up with little > correlation between adjacent pages on-disk. But this can be improved. THe > old swapspace-layout-improvements patch was designed to fix that up, but > needs more testing and tuning. > > It clusters pages on-disk via their virtual address.
2.6 seems in due need of such a patch.
I recently found out that 2.6 kernels degrade horribly when going into swap. On my dual PIII-850 with as little as 256 mb ram, I can easily demonstrate that by opening about 40-50 instances of konquerer with large tables, many images and such things. When the machine is into 80-120 mb of the 256 mb swap partition, it becomes almost unusable. Even the desktop background picture needs ~20sec to update, not to talk about any windows' contents. And you can literally hear the reason for it: the harddisk is seeking like crazy.
I've applied Ingo Molnars swapspace-layout-improvements-2.6.9-rc1-bk12-A1 port of the patch to a 2.6.11-rc1 kernel, and it handles the same workload much smoother. It's slow, but you can work with it.
I just wonder why noone else complained yet. Are systems with tight memory constraints so uncommon these days?
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