Received-SPF: pass (google.com: domain of linux-kernel+bounces-154091-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Mon, 22 Apr 2024 15:32:50 -0700
From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>, LKML
 <linux-kernel@vger.kernel.org>, X86 Kernel <x86@kernel.org>, Peter Zijlstra
 <peterz@infradead.org>, iommu@lists.linux.dev, Lu Baolu
 <baolu.lu@linux.intel.com>, kvm@vger.kernel.org, Dave Hansen
 <dave.hansen@intel.com>, Joerg Roedel <joro@8bytes.org>, "H. Peter Anvin"
 <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>, Ingo Molnar
 <mingo@redhat.com>, Paul Luse <paul.e.luse@intel.com>, Dan Williams
 <dan.j.williams@intel.com>, Jens Axboe <axboe@kernel.dk>, Raj Ashok
 <ashok.raj@intel.com>, "Tian, Kevin" <kevin.tian@intel.com>,
 maz@kernel.org, seanjc@google.com, Robin Murphy <robin.murphy@arm.com>,
 jim.harris@samsung.com, a.manzanares@samsung.com, Bjorn Helgaas
 <helgaas@kernel.org>, guang.zeng@intel.com, robert.hoo.linux@gmail.com,
 kan.liang@intel.com, "Kleen, Andi" <andi.kleen@intel.com>,
 jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH v2 05/13] x86/irq: Reserve a per CPU IDT vector for
 posted MSIs
Message-ID: <20240422153250.07331f49@jacob-builder>
In-Reply-To: <ZiLO9RUdMsNlCtI_@x1>
References: <20240415134354.67c9d1d1@jacob-builder>
	<87jzkuxaqv.ffs@tglx>
	<ZiLO9RUdMsNlCtI_@x1>
Organization: OTC
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Hi Arnaldo,

On Fri, 19 Apr 2024 17:07:17 -0300, Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:

> > > On a second thought, if we make system IRQ vector determined at
> > > compile time based on different CONFIG options, will it break
> > > userspace tools such as perf? More importantly the rule of not
> > > breaking userspace.  
> 
> The rule for tools/perf is "don't impose _any requirement_ on the kernel
> developers, they don't have to test if any change they do outside of
> tools/ will break something inside tools/."
>  
> > tools/arch/x86/include/asm/irq_vectors.h is only used to generate the
> > list of system vectors for pretty output. And your change already broke
> > that.  
> 
> Yeah, I even moved that from tools/arch/x86/include/asm/irq_vectors.h
> to tools/perf/trace/beauty/arch/x86/include/asm/irq_vectors.h (for next
> merge window).

So I will not add anything to the tools directory for my next version.
Just a heads-up for adding this new vector.

Thanks,

Jacob