On Mon, Jun 26, 2023 at 12:03:04PM +0200, Ard Biesheuvel wrote: > > In any case, what I would like to see addressed is the horrid scomp to > acomp layer that ties up megabytes of memory in scratch space, just to > emulate the acomp interface on top of scomp drivers, while no code > exists that makes use of the async nature. Do you have an idea on how > we might address this particular issue? The whole reason why need to allocate megabytes of memory is because of the lack of SG lists in the underlying algorithm. If they actually used SG lists and allocated pages as they went during decompression, then we wouldn't need to pre-allocate any memory at all. It's not going to be easy of course since we need to convert every single algorithm. Perhaps what we could do in the mean time is to get the scomp implementations do exponential retries (e.g., start with allocating size * 2, if that fails then double it, up to whatever we currently pre-allocate). Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
