From: ebiederm@xmission.com (Eric W. Biederman)
To: Tejun Heo <tj@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
hacklu <embedway.linux@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] x86, boot: Optimize the elf header handling.
Date: Mon, 09 Jul 2012 00:03:58 -0700 [thread overview]
Message-ID: <87fw914dr5.fsf@xmission.com> (raw)
In-Reply-To: <20120702165633.GA555@google.com> (Tejun Heo's message of "Mon, 2 Jul 2012 09:56:33 -0700")
Tejun Heo <tj@kernel.org> writes:
> Hello, guys.
>
> On Sun, Jul 01, 2012 at 11:37:22AM -0700, H. Peter Anvin wrote:
>> If we don't need it, I think we can use -z max-page-size=4096, but we
>> use the PMD alignment for percpu on x86-64; Tejun, does that apply to
>> the .data..percpu section in the executable as well?
>
> I don't think the .data..percpu section needs 2M alignment. The
> percpu data section is only used as init template and actual percpu
> addresses always go through offsetting against __per_cpu_offset[] - no
> matter what the vaddrs in the vmlinux are, they get offsetted into 2M
> aligned linear address if necessary. I think the only alignment
> .data..percpu needs is cacheline alignment for separating its
> subsections.
Thanks. My basic testing isn't showing any problems.
Of course all that changed was where in the vmlinux file not where
in physical memory the data was loaded, so problems would really
surprise me.
Eric
next prev parent reply other threads:[~2012-07-09 7:04 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-17 5:56 why the decompressed procedure move kernel from address 0x100000(1M) to 0x1000000(16M) +x hacklu
2012-06-02 23:48 ` Eric W. Biederman
2012-06-03 3:10 ` H. Peter Anvin
2012-06-03 8:41 ` Eric W. Biederman
2012-06-03 13:01 ` H. Peter Anvin
2012-06-03 20:30 ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-06-03 20:32 ` [PATCH 2/2] x86, boot: Optimize the elf header handling Eric W. Biederman
2012-07-01 14:56 ` [tip:x86/boot] " tip-bot for Eric W. Biederman
2012-07-01 15:04 ` [PATCH 2/2] " H. Peter Anvin
2012-07-01 15:34 ` H. Peter Anvin
2012-07-01 16:08 ` Eric W. Biederman
2012-07-01 16:11 ` H. Peter Anvin
2012-07-01 16:26 ` Eric W. Biederman
2012-07-01 16:44 ` H. Peter Anvin
2012-07-01 17:09 ` Eric W. Biederman
2012-07-01 17:15 ` H. Peter Anvin
2012-07-01 18:25 ` Eric W. Biederman
2012-07-01 18:37 ` H. Peter Anvin
2012-07-01 19:20 ` Eric W. Biederman
2012-07-01 19:23 ` H. Peter Anvin
2012-07-01 20:40 ` Eric W. Biederman
2012-07-01 20:52 ` H. Peter Anvin
2012-07-09 6:50 ` Eric W. Biederman
2012-07-09 6:52 ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-09 6:53 ` [PATCH 2/4] x86 boot: Optimize the elf header handling Eric W. Biederman
2012-07-09 6:55 ` [PATCH 3/4] x86 boot: When building vmlinux.bin properly precompute the memory image Eric W. Biederman
2012-07-09 6:56 ` [PATCH 4/4] x86 boot: Tell ld the kernel doesn't want 2MB file offset alignment Eric W. Biederman
2012-07-09 6:59 ` [PATCH 1/4] x86 boot: Jump to the entry point address in the elf header Eric W. Biederman
2012-07-02 16:56 ` [PATCH 2/2] x86, boot: Optimize the elf header handling Tejun Heo
2012-07-09 7:03 ` Eric W. Biederman [this message]
2012-07-01 2:23 ` [PATCH 1/2] x86, boot: Don't overlap the compressed and non-compressed image Eric W. Biederman
2012-07-01 2:32 ` H. Peter Anvin
2012-07-01 5:22 ` Eric W. Biederman
2012-07-01 14:55 ` [tip:x86/boot] x86, boot: Don' t " tip-bot for Eric W. Biederman
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