On Mon, Jan 06, 2025 at 07:10:53PM -0800, Yosry Ahmed wrote: > > The main problem is memory usage. Zswap needs a PAGE_SIZE*2-sized > buffer for each request on each CPU. We preallocate these buffers to > avoid trying to allocate this much memory in the reclaim path (i.e. > potentially allocating two pages to reclaim one). What if we allowed each acomp request to take a whole folio? That would mean you'd only need to allocate one request per folio, regardless of how big it is. Eric, we could do something similar with ahash. Allow the user to supply a folio (or scatterlist entry) instead of a single page, and then cut it up based on a unit-size supplied by the user (e.g., 512 bytes for sector-based users). That would mean just a single request object as long as your input is a folio or something similar. Is this something that you could use in fs/verity? You'd still need to allocate enough memory to store the output hashes. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
