On (24/06/03 11:34), Sergey Senozhatsky wrote: > On (24/06/01 11:54), Herbert Xu wrote: > > On Sat, Jun 01, 2024 at 09:24:15AM +0900, Sergey Senozhatsky wrote: > > > > > > Is it possible to share a tfm? I thought that tfm-s carry some state > > > (compression workmem/scratch buffer) so one cannot do parallel compressions > > > on different CPUs using the same tfm. > > > > Yes the tfm can be shared. The data state is kept in the request > > object. > > Oh, nice, thanks. Herbert, I'm not sure I see how tfm sharing is working. crypto_tfm carries a pointer to __crt_ctx, which e.g. for zstd is struct zstd_ctx, where it keeps all the state (zstd_cctx, zstd_dctx, and compression/decompression workmem buffers). When we call crypto_comp_compress()->zstd_compress() we just pass tfm, then the driver gets tfm-s state/ctx via crypto_tfm_ctx() and uses it for underlying compression library call.
