From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Michal Marek <mmarek@suse.cz>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>,
Namhyung Kim <namhyung@gmail.com>,
Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
X86 ML <x86@kernel.org>,
live-patching@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v8 09/21] x86/paravirt: Align paravirt thunk functions at 16-byte boundaries
Date: Tue, 28 Jul 2015 10:28:39 -0500 [thread overview]
Message-ID: <20150728152839.GA6737@treble.redhat.com> (raw)
In-Reply-To: <CALCETrX4aBxf_apw8oqb_jM_NWp4mSa_8enP_zwF_DX01Dnsiw@mail.gmail.com>
On Tue, Jul 28, 2015 at 08:23:04AM -0700, Andy Lutomirski wrote:
> On Tue, Jul 28, 2015 at 7:47 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > Paravirt thunk functions aren't aligned, which can impact performance
> > and is inconsistent with gcc-generated functions.
> >
> > Align them at 16-byte boundaries to be consistent with gcc functions.
>
> IMO stackvalidate shouldn't warn about this. We've discussed dropping
> the alignment requirement entirely, since it seems to have little
> benefit on modern CPUs.
Stackvalidate didn't actually find this alignment issue. I just noticed
it when fixing the frame pointer issue. If alignment no longer helps
with performance on modern CPUS, it's fine to drop this patch.
--
Josh
next prev parent reply other threads:[~2015-07-28 15:28 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-28 14:46 [PATCH v8 00/21] Compile-time stack validation Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 01/21] x86/asm: Frame pointer macro cleanup Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 02/21] x86/asm: Add C versions of FRAME and ENDFRAME macros Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 03/21] x86/stackvalidate: Compile-time stack validation Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 04/21] x86/stackvalidate: Add file and directory ignores Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 05/21] x86/stackvalidate: Add ignore macros Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 06/21] x86/xen: Add stack frame dependency to hypercall inline asm calls Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 07/21] x86/paravirt: Add stack frame dependency to PVOP " Josh Poimboeuf
2015-07-28 14:46 ` [PATCH v8 08/21] x86/paravirt: Fix frame pointer usage in PV_CALLEE_SAVE_REGS_THUNK Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 09/21] x86/paravirt: Align paravirt thunk functions at 16-byte boundaries Josh Poimboeuf
2015-07-28 15:23 ` Andy Lutomirski
2015-07-28 15:28 ` Josh Poimboeuf [this message]
2015-07-28 14:47 ` [PATCH v8 10/21] x86/amd: Set ELF function type for vide() Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 11/21] x86/reboot: Add ljmp instructions to stackvalidate whitelist Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 12/21] x86/xen: Add xen_cpuid() and xen_setup_gdt() to stackvalidate whitelists Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 13/21] x86/asm/crypto: Fix frame pointer usage in aesni-intel_asm.S Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 14/21] x86/asm/crypto: Move .Lbswap_mask data to .rodata section Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 15/21] x86/asm/crypto: Move jump_table " Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 16/21] x86/asm/crypto: Fix frame pointer usage in clmul_ghash_mul/update() Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 17/21] x86/asm/entry: Fix frame pointer usage in thunk functions Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 18/21] x86/asm/acpi: Fix frame pointer usage in do_suspend_lowlevel() Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 19/21] x86/asm: Fix frame pointer usage in rwsem functions Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 20/21] x86/asm/efi: Fix frame pointer usage in efi_call() Josh Poimboeuf
2015-07-28 14:47 ` [PATCH v8 21/21] x86/asm/power: Fix frame pointer usage in hibernate_asm_64.S Josh Poimboeuf
2015-08-06 8:07 ` [PATCH v8 00/21] Compile-time stack validation Ingo Molnar
2015-08-06 16:06 ` Josh Poimboeuf
2015-08-06 17:23 ` Josh Poimboeuf
2015-08-06 17:46 ` Josh Poimboeuf
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=20150728152839.GA6737@treble.redhat.com \
--to=jpoimboe@redhat.com \
--cc=andi@firstfloor.org \
--cc=bernd@petrovitsch.priv.at \
--cc=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=live-patching@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=mmarek@suse.cz \
--cc=namhyung@gmail.com \
--cc=palves@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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