Now I wonder if my idea of having a muxcall or a batchcall as I thought about it a few years ago is something similar to io_uring, but on a lesser scale and wit

Now I wonder if my idea of having a muxcall or a batchcall as I thought about it a few years ago is something similar to io_uring, but on a lesser scale and without eBPF goodies. My idea was to have a syscall like this: struct batchvec { unsigned long batchv_callnr; unsigned long long batchv_argmask; }; asmlinkage long sys_batchcall(struct batchvec *batchv, int batchvcnt, long args[16], unsigned flags); You were supposed to give in a batchvec a sequence of system call numbers and a little mapping to arguments you provided in args. batchv_argmask is a long long - 64 bit type, this mask is divided to 4 bit fields, every field can address a long from args table. AFAIR Linux syscalls have up to 6 arguments. 6 fields for arguments and one for return value, that gives 7 fields - 28 bits and now I don't remember why I thought I need a long long. It would go like this pseudo code: int i = 0; for(; i < batchvcnt; i++) { args[batchv[i].argmask[6]] = sys_call_table[batchv[i].callnr](args[batchv[i].argmask[0]], args[batchv[i].argmask[1]], args[batchv[i].argmask[2]], args[batchv[i].argmask[3]], args[batchv[i].argmask[4]], args[batchv[i].argmask[5]]); if(args[batchv[i].argmask[6]] < 0) { break; } } return i; It would return a number of successfully run syscalls. It would stop on first failed one. The user would have to pick up the error code out of args table. I would be interested to know why it wouldn't work. I started implementing it against Linux 4.15.12, but never went to test it. I have some code, but I don't believe it is my last version of the attempt.