On Fri, May 10, 2024 at 05:08:27PM +0900, Sergey Senozhatsky wrote: > > For some algorithms params needs to be set before ctx is created. > For example zstd, crypto/zstd calls zstd_get_params(ZSTD_DEF_LEVEL, 0) > to estimate workspace size, which misses the opportunity to configure > it an way zram/zswap can benefit from, because those work with PAGE_SIZE > source buffer. So for zram zstd_get_params(ZSTD_DEF_LEVEL, PAGE_SIZE) > is much better (it saves 1.2MB per ctx, which is per-CPU in zram). Not > to mention that zstd_get_params(param->level, 0) is what we need at the > end. For these algorithms where the overhead of allocating a default set of parameters and then changing them on a setparam call is too high, we could stipulate that the tfm can only be used after a setparam call (just as we require a setkey before cipher ops). Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
