On Mon, Apr 1, 2019 at 6:45 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> > > At Linux Plumbers, Andy Lutomirski approached me and pointed out that the > function call syscall_get_arguments() implemented in x86 was horribly > written and not optimized for the standard case of passing in 0 and 6 for > the starting index and the number of system calls to get. When looking at > all the users of this function, I discovered that all instances pass in only > 0 and 6 for these arguments. Instead of having this function handle > different cases that are never used, simply rewrite it to return the first 6 > arguments of a system call. > > This should help out the performance of tracing system calls by ptrace, > ftrace and perf. [...] > arch/xtensa/include/asm/syscall.h | 16 ++---- For xtensa changes: Acked-by: Max Filippov <jcmvbkbc@xxxxxxxxx> -- Thanks. -- Max
