public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Naveen N Rao <naveen@kernel•org>
To: Christophe Leroy <christophe.leroy@csgroup•eu>,
	Josh Poimboeuf <jpoimboe@kernel•org>,
	Michael Ellerman <mpe@ellerman•id.au>,
	Nicholas Piggin <npiggin@gmail•com>,
	Peter Zijlstra <peterz@infradead•org>,
	Sathvika Vasireddy <sv@linux•ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux•ibm.com>,
	linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org
Subject: Re: [RFC PATCH v1 1/3] Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"
Date: Tue, 20 Jun 2023 10:51:25 +0530	[thread overview]
Message-ID: <1687237941.1wok7iiqm0.naveen@kernel.org> (raw)
In-Reply-To: <8dd72199549e76e0e9c2aba1c89d5fe2b0cb1663.1686922583.git.christophe.leroy@csgroup.eu>

Christophe Leroy wrote:
> This reverts commit 1e688dd2a3d6759d416616ff07afc4bb836c4213.
> 
> That commit aimed at optimising the code around generation of
> WARN_ON/BUG_ON but this leads to a lot of dead code erroneously
> generated by GCC.
> 
>      text	   data	    bss	    dec	    hex	filename
>   9551585	3627834	 224376	13403795	 cc8693	vmlinux.before
>   9535281	3628358	 224376	13388015	 cc48ef	vmlinux.after
> 
> Once this change is reverted, in a standard configuration (pmac32 +
> function tracer) the text is reduced by 16k which is around 1.7%

Aneesh recently reported a build failure due to the use of 'asm goto' in  
WARN_ON(). We were able to root-cause it to the use of 'asm goto' with 
two config options: CONFIG_CC_OPTIMIZE_FOR_SIZE and 
CONFIG_DEBUG_SECTION_MISMATCH.

Along with the issues we found with 'asm goto' during objtool 
enablement, I think it might be better to disable it for now.
Acked-by: Naveen N Rao <naveen@kernel•org>


- Naveen


  reply	other threads:[~2023-06-20  5:29 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-16 13:47 [RFC PATCH v1 0/3] powerpc/objtool: First step towards uaccess validation (v1) Christophe Leroy
2023-06-16 13:47 ` [RFC PATCH v1 1/3] Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto" Christophe Leroy
2023-06-20  5:21   ` Naveen N Rao [this message]
2023-06-20  7:10     ` Peter Zijlstra
2023-06-16 13:47 ` [RFC PATCH v1 2/3] powerpc: Mark all .S files invalid for objtool Christophe Leroy
2023-06-20  6:04   ` Naveen N Rao
2023-06-20  6:15     ` Christophe Leroy
2023-06-20  6:40       ` Naveen N Rao
2023-06-16 13:47 ` [RFC PATCH v1 3/3] powerpc: WIP draft support to objtool check Christophe Leroy
2023-06-16 14:43   ` Peter Zijlstra

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1687237941.1wok7iiqm0.naveen@kernel.org \
    --to=naveen@kernel$(echo .)org \
    --cc=aneesh.kumar@linux$(echo .)ibm.com \
    --cc=christophe.leroy@csgroup$(echo .)eu \
    --cc=jpoimboe@kernel$(echo .)org \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=mpe@ellerman$(echo .)id.au \
    --cc=npiggin@gmail$(echo .)com \
    --cc=peterz@infradead$(echo .)org \
    --cc=sv@linux$(echo .)ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox