On Tue, Sep 11, 2018 at 12:12 PM, Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> wrote: > We noticed the performance bottle neck in FUSE running our > Virtuozzo storage over rdma. On some types of workload > we observe 20% of times pent in request_find() in profiler. > This function is iterating over long requests list, and it > scales bad. > > The patch introduces hash table to reduce the number > of iterations, we do in this function. Hash generating > algorithm is taken from hash_add() function, while > 512 lines table is used to store pending requests. > This fixes problem and improves the performance. Pushed to fuse.git#for-next with a number of small changes. E.g. I reduced the number of cachlines to 256 to make the hashtable size just 4k. Was there a scientific reason for choosing 512 as the optimal number of cache lines? Thanks, Miklos
