On 08/31/2017 06:31 AM, Dan Streetman wrote: > On Tue, Aug 29, 2017 at 5:54 PM, Haren Myneni <haren@xxxxxxxxxxxxxxxxxx> wrote: >> On 08/29/2017 02:23 PM, Benjamin Herrenschmidt wrote: >>> On Tue, 2017-08-29 at 09:58 -0400, Dan Streetman wrote: >>>>> + >>>>> + ret = -EINVAL; >>>>> + if (coproc && coproc->vas.rxwin) { >>>>> + wmem->txwin = nx842_alloc_txwin(coproc); >>>> >>>> this is wrong. the workmem is scratch memory that's valid only for >>>> the duration of a single operation. >> >> Correct, workmem is used until crypto_free is called. > > that's not a 'single operation'. a single operation is compress() or > decompress(). workmem is allocated in nx842_crypto_init (called from crypto_alloc) and freed in crypto_free(). We can have single compression / decompression() operation or multiple within this crypto session. In case of single operation, we will end up workmem, ctx->sbounce/dbounce alloc/free for each request. > >>>> >>>> do you actually need a txwin per crypto transform? or do you need a >>>> txwin per coprocessor? or txwin per processor? either per-coproc or >>>> per-cpu should be created at driver init and held separately >>>> (globally) instead of a per-transform txwin. I really don't see why >>>> you would need a txwin per transform, because the coproc should not >>>> care how many different transforms there are. >>> >>> We should only need a single window for the whole kernel really, plus >>> one per user process who wants direct access but that's not relevant >>> here. >> >> Opening send window for each crypto transform (crypto_alloc, >> compression/decompression, ..., crypto_free) so that does not >> have to wait for the previous copy/paste complete. >> VAS will map send and receive windows, and can cache in send >> windows (up to 128). So I thought using the same send window >> (per chip) for more requests (say 1000) may be adding overhead. >> >> I will make changes if you prefer using 1 send window per chip. > > i don't have the spec, so i shouldn't be making the decision on it, > but i do know putting a persistent field into the workmem is the wrong > location. If it's valid for the life of the transform, put it into > the transform context. The workmem buffer is intended to be used only > during a single operation - it's "working memory" to perform each > individual crypto transformation. > >> >>> >>> Cheers, >>> Ben. >>> >> >