Messages in this thread | | | Date | Wed, 20 Oct 2021 11:46:38 +0000 | From | Hyeonggon Yoo <> | Subject | Re: [PATCH] slob: add size header to all allocations |
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On Sun, Oct 17, 2021 at 08:38:41PM -0700, Rustam Kovhaev wrote: > Let's prepend all allocations of (PAGE_SIZE - align_offset) and less > with the size header. This way kmem_cache_alloc() memory can be freed > with kfree() and the other way around, as long as they are less than > (PAGE_SIZE - align_offset).
Hello Rustam, I measured its impact on memory usage on tiny kernel configuration as SLOB is used in very small machine.
on x86 32 bit + tinyconfig: Before: Slab: 668 kB
After: Slab: 688~692 kB
it adds 20~24kB.
> > The main reason for this change is to simplify SLOB a little bit, make > it a bit easier to debug whenever something goes wrong. >
It seems acceptable But I wonder it is worth to increase memory usage to allow freeing kmem_cache_alloc-ed objects by kfree()?
Thanks, Hyeonggon
> meminfo right after the system boot, without the patch: > Slab: 35500 kB > > the same, with the patch: > Slab: 36396 kB >
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