Switching to vm.page-cluster=0 on new installs

This is my first post here and my first try at making a suggestion of an open source project. (if this is not the right place for proposals, please direct me elsewhere :slight_smile: )


Default fedora installations use only ZRAM as a swap and so I think it would be a good idea to switch the defaults of sysctl from vm.page-cluster=3 to vm.page-cluster=0.


From my understaning of reading this documentation and this piece from segmentfault it seems that page-cluster=3 is set with HDDs and SSDs in mind in mind, but doesn’t fit the usecase of compressed in memory block device like ZRAM, making unnecessary reads and therefore wasting cpu time on decompression (and probably lowering IOPS) with no tangible benefit to performance. This is also supported by chromeos disabling page-cluster while using ZRAM, as chromebooks are usually low memory computers, so heavy ZRAM usage there is expected.

Closing notes:

There are probably many more optimizations regarding ZRAM, but this one seems pretty simple to implement and without any obvious drawbacks.

Also I have no idea how to properly benchmark the possible benefits of this change, so I would really appreciate anyone more experienced than me chiming in on this.

(I could be totally wrong on all of this, what do I know :slight_smile: )

chromeos sysctl (couldn’t put more than 2 links in my first post)

The Development Mailing List would probably be a better place to start the dicussion.

You should probably also take a look at, Changes policy :: Fedora Docs

Thanks and Welcome to ask :fedora: , when you have a minute please take a look at, Welcome to Ask Fedora! Please read me first!

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Thanks for your reply and for pointing me in the right direction, I will go over all the links you provided (some of which I should have probably already read :sweat_smile: ).

Thank you for your time, and have a nice day :slight_smile:

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