Hello, Oleg Nesterov <o...@redhat.com> wrote: > Thanks!
Dave gave this his: Tested-By: Dave Hansen <dave.han...@intel.com> over under v1 of this patch: https://lkml.kernel.org/g/5543c277.9070...@intel.com Anything else anyone sees, or anyone in particular I have to poke at to get this in? Ingo? yours, Bobby On Mon, Apr 27, 2015 at 11:19 AM, Oleg Nesterov <o...@redhat.com> wrote: > Thanks! > > On 04/27, Bobby Powers wrote: >> >> v2: switch used_math() -> tsk_used_math(tsk) to consistently use the >> grabbed tsk instead of current, like in the rest of flush_thread(). >> >> Oleg's commit f893959b ("x86/fpu: Don't abuse drop_init_fpu() in >> flush_thread()") removed drop_init_fpu() usage from flush_thread. >> This seems to break things for me - the Go 1.4 test suite fails all >> over the place with floating point comparision errors (offending >> commit found through bisection). >> >> The functional change was that flush_thread after f893959b only calls >> restore_init_xstate when both use_eager_fpu() and !used_math() are >> true. drop_init_fpu (now fpu_reset_state) calls restore_init_xstate() >> regardless of whether current used_math() - apply the same logic here. >> >> Fixes: f893959b ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()") >> Signed-off-by: Bobby Powers <bobbypow...@gmail.com> >> Acked-by: Oleg Nesterov <o...@redhat.com> >> Cc: Andi Kleen <a...@linux.intel.com> >> Cc: Borislav Petkov <b...@suse.de> >> Cc: Ingo Molnar <mi...@kernel.org> >> Cc: Andy Lutomirski <l...@amacapital.net> >> Cc: Dave Hansen <dave.han...@intel.com> >> Cc: Fenghua Yu <fenghua...@intel.com> >> Cc: Linus Torvalds <torva...@linux-foundation.org> >> Cc: Pekka Riikonen <priik...@iki.fi> >> Cc: Quentin Casasnovas <quentin.casasno...@oracle.com> >> Cc: Rik van Riel <r...@redhat.com> >> Cc: Suresh Siddha <sbsid...@gmail.com> >> --- >> arch/x86/kernel/process.c | 12 +++++++----- >> 1 file changed, 7 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c >> index 8213da6..1a6fcf8 100644 >> --- a/arch/x86/kernel/process.c >> +++ b/arch/x86/kernel/process.c >> @@ -156,11 +156,13 @@ void flush_thread(void) >> /* FPU state will be reallocated lazily at the first use. */ >> drop_fpu(tsk); >> free_thread_xstate(tsk); >> - } else if (!used_math()) { >> - /* kthread execs. TODO: cleanup this horror. */ >> - if (WARN_ON(init_fpu(tsk))) >> - force_sig(SIGKILL, tsk); >> - user_fpu_begin(); >> + } else { >> + if (!tsk_used_math(tsk)) { >> + /* kthread execs. TODO: cleanup this horror. */ >> + if (WARN_ON(init_fpu(tsk))) >> + force_sig(SIGKILL, tsk); >> + user_fpu_begin(); >> + } >> restore_init_xstate(); >> } >> } >> -- >> 2.3.6 >> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
