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From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: "H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>
Subject: Re: [PATCH v2] Place ENTRY_POINT in .text.unlikely section [BZ #28153]
Date: Sat, 31 Jul 2021 18:36:26 +0200	[thread overview]
Message-ID: <87o8aiv3sl.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20210731151316.1659316-1-hjl.tools@gmail.com> (H. J. Lu via Libc-alpha's message of "Sat, 31 Jul 2021 08:13:16 -0700")

* H. J. Lu via Libc-alpha:

> diff --git a/sysdeps/aarch64/start.S b/sysdeps/aarch64/start.S
> index 417da8802b..e46e01ed0b 100644
> --- a/sysdeps/aarch64/start.S
> +++ b/sysdeps/aarch64/start.S
> @@ -42,7 +42,7 @@
>  					NULL
>   */
>  
> -	.text
> +	.section .text.unlikely,"ax",%progbits
>  ENTRY(_start)
>  	/* Create an initial frame with 0 LR and FP */
>  	cfi_undefined (x30)

I don't think it's correct to place code that runs during every process
start into .text.unlikely.  Surely we can avoid that page fault.

Can we fix the ENTRY_POINT assumption in profiling instead?

Thanks,
Florian


  reply	other threads:[~2021-07-31 16:36 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-31 15:13 [PATCH v2] Place ENTRY_POINT in .text.unlikely section [BZ #28153] H.J. Lu via Libc-alpha
2021-07-31 16:36 ` Florian Weimer via Libc-alpha [this message]
2021-07-31 17:06   ` H.J. Lu via Libc-alpha
2021-07-31 17:09     ` H.J. Lu via Libc-alpha
2021-07-31 17:11     ` Florian Weimer via Libc-alpha
2021-07-31 17:34       ` Andreas Schwab
2021-07-31 17:43       ` [PATCH v3] Use __executable_start as the lowest address for profiling " H.J. Lu via Libc-alpha

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