Hi Steven, On Mon, Apr 01, 2019 at 09:41:09AM -0400, Steven Rostedt 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. > > Link: http://lkml.kernel.org/r/20161107213233.754809394@xxxxxxxxxxx > > Cc: Oleg Nesterov <oleg@xxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > Cc: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> > Cc: Dave Martin <dave.martin@xxxxxxx> > Cc: "Dmitry V. Levin" <ldv@xxxxxxxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: linux-c6x-dev@xxxxxxxxxxxxx > Cc: uclinux-h8-devel@xxxxxxxxxxxxxxxxxxxx > Cc: linux-hexagon@xxxxxxxxxxxxxxx > Cc: linux-ia64@xxxxxxxxxxxxxxx > Cc: linux-mips@xxxxxxxxxxxxxxx > Cc: nios2-dev@xxxxxxxxxxxxxxxxxxxxxx > Cc: openrisc@xxxxxxxxxxxxxxxxxxxx > Cc: linux-parisc@xxxxxxxxxxxxxxx > Cc: linuxppc-dev@xxxxxxxxxxxxxxxx > Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx > Cc: linux-s390@xxxxxxxxxxxxxxx > Cc: linux-sh@xxxxxxxxxxxxxxx > Cc: sparclinux@xxxxxxxxxxxxxxx > Cc: linux-um@xxxxxxxxxxxxxxxxxxx > Cc: linux-xtensa@xxxxxxxxxxxxxxxx > Cc: linux-arch@xxxxxxxxxxxxxxx > Reported-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Acked-by: Paul Burton <paul.burton@xxxxxxxx> # MIPS parts Thanks, Paul _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
