From: Peter Zijlstra <peterz@infradead•org>
To: "Naveen N. Rao" <naveen.n.rao@linux•vnet.ibm.com>
Cc: "aik@ozlabs•ru" <aik@ozlabs•ru>,
"linux-kernel@vger•kernel.org" <linux-kernel@vger•kernel.org>,
Sathvika Vasireddy <sv@linux•ibm.com>,
"rostedt@goodmis•org" <rostedt@goodmis•org>,
"jpoimboe@redhat•com" <jpoimboe@redhat•com>,
"mbenes@suse•cz" <mbenes@suse•cz>,
"linuxppc-dev@lists•ozlabs.org" <linuxppc-dev@lists•ozlabs.org>
Subject: Re: [RFC PATCH 1/4] objtool: Add --mnop as an option to --mcount
Date: Wed, 25 May 2022 13:36:42 +0200 [thread overview]
Message-ID: <Yo4UysC69UCwhlYp@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1653388084.w21cyb07gc.naveen@linux.ibm.com>
On Tue, May 24, 2022 at 04:01:48PM +0530, Naveen N. Rao wrote:
> We need to know for sure either way. Nop'ing out the _mcount locations at
> boot allows us to discover existing long branch trampolines. If we want to
> avoid it, we need to note down those locations during build time.
>
> Do you have a different approach in mind?
If you put _mcount in a separate section then the compiler cannot tell
where it is and is forced to always emit a long branch trampoline.
Does that help?
next prev parent reply other threads:[~2022-05-25 11:37 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-23 17:55 [RFC PATCH 0/4] objtool: Enable and implement --mcount option on powerpc Sathvika Vasireddy
2022-05-23 17:55 ` [RFC PATCH 1/4] objtool: Add --mnop as an option to --mcount Sathvika Vasireddy
2022-05-24 8:54 ` Christophe Leroy
2022-05-24 10:15 ` Naveen N. Rao
2022-05-24 10:20 ` Christophe Leroy
2022-05-24 10:31 ` Naveen N. Rao
2022-05-25 11:36 ` Peter Zijlstra [this message]
2022-05-26 11:51 ` Naveen N. Rao
2022-05-23 17:55 ` [RFC PATCH 2/4] objtool: Enable objtool to run only on files with ftrace enabled Sathvika Vasireddy
2022-05-24 8:57 ` Christophe Leroy
2022-05-24 10:53 ` Sathvika Vasireddy
2022-05-24 13:28 ` Christophe Leroy
2022-05-23 17:55 ` [RFC PATCH 3/4] objtool/powerpc: Enable objtool to be built on ppc Sathvika Vasireddy
2022-05-24 9:13 ` Christophe Leroy
2022-05-23 17:55 ` [RFC PATCH 4/4] objtool/powerpc: Add --mcount specific implementation Sathvika Vasireddy
2022-05-24 9:35 ` Christophe Leroy
2022-05-24 11:00 ` Sathvika Vasireddy
2022-05-24 13:33 ` Christophe Leroy
2022-05-25 17:27 ` Christophe Leroy
2022-05-31 6:20 ` Christophe Leroy
2022-06-16 13:34 ` Naveen N. Rao
2022-06-16 13:40 ` Christophe Leroy
2022-06-16 13:57 ` Peter Zijlstra
2022-06-16 14:06 ` Christophe Leroy
2022-06-17 14:04 ` Naveen N. Rao
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