important question!

hi,
i want to add a comprissing syscall in the linux kernel in order to improve the work of the swapper.
The commprissing function and the decomprissing one take a buffer as an argument.now i am trying to find the right line to insert the compriss and decompriis in i meen the place in thre code before the buffer of data became a page and after a page become a buffer od data. i still searching and reading the linux code i think my answer should be in page_io.c.
please help me i need the answer today.
thanx in advance
nada shalabi

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Could you describe how the improvement would be achieved with this ? Under what conditions ?

You don't want to make a syscall -- those are where kernel supplies
some service for the userspace. What you do want is to add a block
compression function call within the kernel itself.

Now if that thing you have in mind would make sense, why it hasn't been done in past 10 years ? (It has been proposed a few times, though.)

That is due to:
- You can't compress compressed data
- In worst case, you end up needing MORE space than you
begun with (even one bit more space is too much.)

Sure enough it might work for most of the time, but when you get a page full of maximum entropy data, and try to swap that, things fail.