Messages in this thread | | | Date | Thu, 18 May 2023 21:24:31 -0400 | From | Kent Overstreet <> | Subject | Re: [RFC PATCH 1/5] mm: intorduce __GFP_UNMAPPED and unmapped_alloc() |
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On Thu, May 18, 2023 at 01:51:08PM -0700, Song Liu wrote:
> To allocate memory for text, we will allocate 2MiB, make it ROX, and then > use it for many small allocations. IIUC, buddy allocator will use unallocated > parts of this page for metadata. I guess this may be a problem, as the > whole page is ROX now, and we have to use text_poke to write to it.
The standard kernel buddy allocator does _not_ store anything in the page itself - because the page might be a highmem page.
That's also why I went with the bitmap for my slab allocator; standard kernel slab allocator stores a freelist ptr in free objects.
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