From: Dan Raymond <raymod2@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Greg KH <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-serial <linux-serial@vger.kernel.org>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org,
andriy.shevchenko@linux.intel.com, quic_saipraka@quicinc.com
Subject: Re: [PATCH v5] arch/x86: port I/O tracing on x86
Date: Mon, 23 Oct 2023 15:29:53 -0600 [thread overview]
Message-ID: <78787d18-0f30-4be0-9e7c-1b6dbf142fec@gmail.com> (raw)
In-Reply-To: <20231021161503.382e3d2e@rorschach.local.home>
On 10/21/2023 2:15 PM, Steven Rostedt wrote:
>> Why are these needed to be changed at all? What code changes with it,
>> and it's not mentioned in the changelog, so why is it required?
>
> Agreed, if this has issues, it probably should be a separate patch.
As I mentioned to Greg, this fix is needed to avoid compiler warnings
triggered by this patch. If I submitted this separately it would have
to be merged first. Isn't it easier to combine them since this is
not a functional change (it just makes a cast explicit)?
>>> -#ifdef CONFIG_TRACEPOINTS
>>> +#if defined(CONFIG_TRACEPOINTS) && !defined(DISABLE_TRACEPOINTS)
>>
>> Why this global change?
>
> Yeah, DISABLE_TRACEPOINTS does not currently exist. If this is to be a
> new way to disable TRACEPOINTS it needs a separate patch and be able to
> disable tracepoints everywhere (maybe include/trace/*.h files also need
> to be modified?), and also be documented somewhere in Documentation/trace.
It's only needed to suppress compiler errors when building arch/x86/boot/*
and arch/x86/realmode/*. Those source files include various x86 headers
such as <asm/msr.h> and <asm/shared/io.h>. Those x86 headers include
<linux/tracepoint-defs.h> which references static_key_false() in
<linux/jump_label.h>. DISABLE_TRACEPOINTS eliminates that reference and
hence suppresses the compiler error.
I didn't intend for this macro to be used by developers adding new
tracepoints so I didn't document it as such. As far as creating a
separate patch: again this is a requirement for this patch and it doesn't
cause any functional changes so can't we combine them?
next prev parent reply other threads:[~2023-10-23 21:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-29 19:15 [PATCH v3] arch/x86: port I/O tracing on x86 Dan Raymond
2023-10-03 12:50 ` Greg KH
2023-10-04 22:54 ` Dan Raymond
2023-10-04 23:50 ` Steven Rostedt
2023-10-06 21:29 ` Dan Raymond
2023-10-06 21:32 ` [PATCH v4] " Dan Raymond
2023-10-07 6:53 ` kernel test robot
2023-10-07 17:56 ` [PATCH v5] " Dan Raymond
2023-10-11 20:22 ` Dan Raymond
2023-10-11 20:41 ` Greg KH
2023-10-21 16:00 ` Greg KH
2023-10-21 20:15 ` Steven Rostedt
2023-10-23 21:29 ` Dan Raymond [this message]
2023-10-23 21:51 ` Steven Rostedt
2023-10-23 20:28 ` Dan Raymond
2023-10-24 9:32 ` Greg KH
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