• Denys Vlasenko's avatar
    x86/asm/entry/64: Simplify looping around preempt_schedule_irq() · 36acef25
    Denys Vlasenko authored
    At the 'exit_intr' label we test whether interrupt/exception was in
    kernel. If it did, we jump to the preemption check. If preemption
    does happen (IOW if we call preempt_schedule_irq()), we go back to
    'exit_intr'.
    
    But it's pointless, we already know that the test succeeded last
    time, preemption doesn't change the fact that interrupt/exception
    was in the kernel.
    
    We can go back directly to checking PER_CPU_VAR(__preempt_count) instead.
    
    This makes the 'exit_intr' label unused, drop it.
    Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
    Cc: Alexei Starovoitov <ast@plumgrid.com>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Kees Cook <keescook@chromium.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Will Drewry <wad@chromium.org>
    Link: http://lkml.kernel.org/r/1427821211-25099-5-git-send-email-dvlasenk@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    36acef25
entry_64.S 41.1 KB