Date: Sat, 3 Oct 2020 13:01:07 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r366392 - head/sys/riscv/riscv Message-ID: <202010031301.093D17aN018915@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: trasz Date: Sat Oct 3 13:01:07 2020 New Revision: 366392 URL: https://svnweb.freebsd.org/changeset/base/366392 Log: Optimize riscv's cpu_fetch_syscall_args(), making it possible for the compiler to inline the memcpy. Reviewed by: arichardson, mhorne MFC after: 2 weeks Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D26528 Modified: head/sys/riscv/riscv/trap.c Modified: head/sys/riscv/riscv/trap.c ============================================================================== --- head/sys/riscv/riscv/trap.c Sat Oct 3 12:03:08 2020 (r366391) +++ head/sys/riscv/riscv/trap.c Sat Oct 3 13:01:07 2020 (r366392) @@ -96,30 +96,31 @@ int cpu_fetch_syscall_args(struct thread *td) { struct proc *p; - register_t *ap; + register_t *ap, *dst_ap; struct syscall_args *sa; - int nap; - nap = NARGREG; p = td->td_proc; sa = &td->td_sa; ap = &td->td_frame->tf_a[0]; + dst_ap = &sa->args[0]; sa->code = td->td_frame->tf_t[0]; - if (sa->code == SYS_syscall || sa->code == SYS___syscall) { + if (__predict_false(sa->code == SYS_syscall || sa->code == SYS___syscall)) { sa->code = *ap++; - nap--; + } else { + *dst_ap++ = *ap++; } - if (sa->code >= p->p_sysent->sv_size) + if (__predict_false(sa->code >= p->p_sysent->sv_size)) sa->callp = &p->p_sysent->sv_table[0]; else sa->callp = &p->p_sysent->sv_table[sa->code]; - memcpy(sa->args, ap, nap * sizeof(register_t)); - if (sa->callp->sy_narg > nap) - panic("TODO: Could we have more then %d args?", NARGREG); + KASSERT(sa->callp->sy_narg <= nitems(sa->args), + ("Syscall %d takes too many arguments", sa->code)); + + memcpy(dst_ap, ap, (NARGREG - 1) * sizeof(register_t)); td->td_retval[0] = 0; td->td_retval[1] = 0;
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202010031301.093D17aN018915>