Messages in this thread | | | Date | Wed, 1 May 2019 17:51:51 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH v2 3/6] x86: clean up _TIF_SYSCALL_EMU handling using ptrace_syscall_enter hook |
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On Wed, May 01, 2019 at 05:57:11PM +0200, Oleg Nesterov wrote: > On 04/30, Sudeep Holla wrote: > > > > On Mon, Mar 18, 2019 at 04:33:22PM +0100, Oleg Nesterov wrote: > > > > > > And it seems that _TIF_WORK_SYSCALL_ENTRY needs some cleanups too... We don't need > > > "& _TIF_WORK_SYSCALL_ENTRY" in syscall_trace_enter, and _TIF_WORK_SYSCALL_ENTRY > > > should not include _TIF_NOHZ? > > > > > > > I was about to post the updated version and checked this to make sure I have > > covered everything or not. I had missed the above comment. All architectures > > have _TIF_NOHZ in their mask that they check to do work. And from x86, I read > > "...syscall_trace_enter(). Also includes TIF_NOHZ for enter_from_user_mode()" > > So I don't understand why _TIF_NOHZ needs to be dropped. > > I have already forgot this discussion... But after I glanced at this code again > I still think the same, and I don't understand why do you disagree. >
Sorry, but I didn't have any disagreement, I just said I don't understand the usage on all architectures at that moment.
> > Also if we need to drop, we can address that separately examining all archs. > > Sure, and I was only talking about x86. We can keep TIF_NOHZ and even > set_tsk_thread_flag(TIF_NOHZ) in context_tracking_cpu_set() if some arch needs > this but remove TIF_NOHZ from TIF_WORK_SYSCALL_ENTRY in arch/x86/include/asm/thread_info.h, > afaics this shouldn't make any difference. >
OK, it's just x86, then I understand your point. I was looking at all the architectures, sorry for the confusion.
> And I see no reason why x86 needs to use TIF_WORK_SYSCALL_ENTRY in > syscall_trace_enter(). >
Agreed
-- Regards, Sudeep
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