Messages in this thread Patch in this message | | | Date | Wed, 4 Apr 2018 17:57:04 +0200 | From | Greg KH <> | Subject | Re: [PATCH v2 char-misc 1/1] x86/hyperv: Add interrupt handler annotations |
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On Wed, Apr 04, 2018 at 03:47:03PM +0000, Michael Kelley (EOSG) wrote: > > -----Original Message----- > > From: Greg KH <gregkh@linuxfoundation.org> > > Sent: Wednesday, April 4, 2018 1:16 AM > > To: Michael Kelley (EOSG) <Michael.H.Kelley@microsoft.com> > > Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org; olaf@aepfle.de; > > apw@canonical.com; vkuznets@redhat.com; jasowang@redhat.com; > > leann.ogasawara@canonical.com; marcelo.cerri@canonical.com; Stephen Hemminger > > <sthemmin@microsoft.com>; KY Srinivasan <kys@microsoft.com> > > Subject: Re: [PATCH v2 char-misc 1/1] x86/hyperv: Add interrupt handler annotations > > > > On Tue, Apr 03, 2018 at 01:59:08PM -0700, mhkelley58@gmail.com wrote: > > > From: Michael Kelley <mikelley@microsoft.com> > > > > > > Add standard interrupt handler annotations to > > > hyperv_vector_handler(). > > > > > > Signed-off-by: Michael Kelley <mikelley@microsoft.com> > > > --- > > > Changes in v2: > > > * Fixed From: line > > > --- > > > arch/x86/kernel/cpu/mshyperv.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > > > index 4488cf0..20f6849 100644 > > > --- a/arch/x86/kernel/cpu/mshyperv.c > > > +++ b/arch/x86/kernel/cpu/mshyperv.c > > > @@ -41,7 +41,7 @@ static void (*hv_stimer0_handler)(void); > > > static void (*hv_kexec_handler)(void); > > > static void (*hv_crash_handler)(struct pt_regs *regs); > > > > > > -void hyperv_vector_handler(struct pt_regs *regs) > > > +__visible void __irq_entry hyperv_vector_handler(struct pt_regs *regs) > > > > What bug does this solve? What is wrong with the existing markings? > > What does __visible and __irq_entry give us that we don't already have > > and we need? > > > > Are you really using LTO that requires this marking to prevent the code > > from being removed? > > Thomas Gleixner commented on Vitaly Kuznetsov's Hyper-V reenlightenment patch > that the interrupt handler should have these annotations: see > https://lkml.org/lkml/2018/1/14/145
Ok, then someone needs to put a "Suggested-by:" or "Requested-by:" or something like that tag here, right?
> I put the same annotations on the interrupt handler for stimer0 Direct Mode, > So this change makes the hyperv_vector_handler() consistent with > hv_stimer0_vector_handler() in the same source file. It does not fix any > immediate bug -- it's for consistency and alignment with what is apparently > standard practice. > > Not sure what LTO is ...
That's what the __visable marking fixes! Please go at least _read_ the definition of the marking you are adding to a function before doing it. Otherwise this is just cargo-cult-coding :(
thanks,
greg k-h
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