linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
	clang-built-linux@googlegroups.com, x86@kernel.org,
	Will Deacon <will.deacon@arm.com>, Arnd Bergmann <arnd@arndb.de>,
	Russell King <linux@armlinux.org.uk>,
	Paul Burton <paul.burton@mips.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>, Stephen Boyd <sboyd@kernel.org>,
	Mark Salyzyn <salyzyn@android.com>,
	Kees Cook <keescook@chromium.org>,
	Peter Collingbourne <pcc@google.com>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	Andrei Vagin <avagin@openvz.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Marc Zyngier <maz@kernel.org>,
	Mark Rutland <Mark.Rutland@arm.com>,
	Will Deacon <will@kernel.org>
Subject: Re: [PATCH v3 21/26] arm64: Introduce asm/vdso/arch_timer.h
Date: Mon, 16 Mar 2020 15:37:23 +0000	[thread overview]
Message-ID: <4914ad9c-3eaf-b328-f31b-5d3077ef272f@arm.com> (raw)
In-Reply-To: <20200315183151.GE32205@mbp>

Hi Catalin,

On 3/15/20 6:32 PM, Catalin Marinas wrote:
> On Fri, Mar 13, 2020 at 03:43:40PM +0000, Vincenzo Frascino wrote:
>> The vDSO library should only include the necessary headers required for
>> a userspace library (UAPI and a minimal set of kernel headers). To make
>> this possible it is necessary to isolate from the kernel headers the
>> common parts that are strictly necessary to build the library.
>>
>> Introduce asm/vdso/arch_timer.h to contain all the arm64 specific
>> code. This allows to replace the second isb() in __arch_get_hw_counter()
>> with a fake dependent stack read of the counter which improves the vdso
>> library peformances of ~4.5%. Below the results of vdsotest [1] ran for
>> 100 iterations.
> 
> The subject seems to imply a non-functional change but as you read, it
> gets a lot more complicated. Could you keep the functional change
> separate from the header clean-up, maybe submit it as an independent
> patch? And it shouldn't go in without Will's ack ;).
> 

It is fine by me. I will repost the series with the required fixes and without
this patch. This will give to me enough time to address Mark's comments as well
and to Will to have a proper look.

-- 
Regards,
Vincenzo

  reply	other threads:[~2020-03-16 15:37 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-13 15:43 [PATCH v3 00/26] Introduce common headers for vDSO Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 01/26] linux/const.h: Extract common header " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 02/26] linux/bits.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 03/26] linux/limits.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 04/26] x86:Introduce asm/vdso/clocksource.h Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 05/26] arm: Introduce asm/vdso/clocksource.h Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 06/26] arm64: " Vincenzo Frascino
2020-03-15 18:29   ` Catalin Marinas
2020-03-13 15:43 ` [PATCH v3 07/26] mips: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 08/26] linux/clocksource.h: Extract common header for vDSO Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 09/26] linux/math64.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 10/26] linux/time.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 11/26] linux/time32.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 12/26] linux/time64.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 13/26] linux/jiffies.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 14/26] linux/ktime.h: " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 15/26] common: Introduce processor.h Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 16/26] scripts: Fix the inclusion order in modpost Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 17/26] linux/elfnote.h: Replace elf.h with UAPI equivalent Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 18/26] arm64: Introduce asm/vdso/processor.h Vincenzo Frascino
2020-03-15 18:30   ` Catalin Marinas
2020-03-16  9:42     ` Vincenzo Frascino
2020-03-16 10:22       ` Mark Rutland
2020-03-16 10:26         ` Catalin Marinas
2020-03-16 10:29           ` Mark Rutland
2020-03-16 10:30           ` Vincenzo Frascino
2020-03-16 10:29         ` Vincenzo Frascino
2020-03-16 10:34       ` Catalin Marinas
2020-03-16 10:55         ` Vincenzo Frascino
2020-03-16 11:22           ` Catalin Marinas
2020-03-16 13:35             ` Vincenzo Frascino
2020-03-16 14:43               ` Catalin Marinas
2020-03-16 15:33                 ` Vincenzo Frascino
2020-03-16 15:49                   ` Catalin Marinas
2020-03-16 16:05                     ` Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 19/26] arm64: vdso: Include common headers in the vdso library Vincenzo Frascino
2020-03-15 18:30   ` Catalin Marinas
2020-03-13 15:43 ` [PATCH v3 20/26] arm64: vdso32: " Vincenzo Frascino
2020-03-15 18:30   ` Catalin Marinas
2020-03-13 15:43 ` [PATCH v3 21/26] arm64: Introduce asm/vdso/arch_timer.h Vincenzo Frascino
2020-03-15 18:32   ` Catalin Marinas
2020-03-16 15:37     ` Vincenzo Frascino [this message]
2020-04-09 13:26       ` Will Deacon
2020-04-09 13:36         ` Vincenzo Frascino
2020-03-16 10:28   ` Mark Rutland
2020-03-13 15:43 ` [PATCH v3 22/26] mips: vdso: Enable mips to use common headers Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 23/26] x86: vdso: Enable x86 " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 24/26] arm: vdso: Enable arm " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 25/26] lib: vdso: Enable " Vincenzo Frascino
2020-03-13 15:43 ` [PATCH v3 26/26] arm64: vdso32: Enable Clang Compilation Vincenzo Frascino
2020-03-16  9:17   ` Catalin Marinas
2020-03-13 16:19 ` [PATCH v3 00/26] Introduce common headers for vDSO Dmitry Safonov
2020-03-15 10:02   ` Thomas Gleixner

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=4914ad9c-3eaf-b328-f31b-5d3077ef272f@arm.com \
    --to=vincenzo.frascino@arm.com \
    --cc=0x7f454c46@gmail.com \
    --cc=Mark.Rutland@arm.com \
    --cc=arnd@arndb.de \
    --cc=avagin@openvz.org \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=clang-built-linux@googlegroups.com \
    --cc=keescook@chromium.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=luto@kernel.org \
    --cc=maz@kernel.org \
    --cc=mingo@redhat.com \
    --cc=ndesaulniers@google.com \
    --cc=paul.burton@mips.com \
    --cc=pcc@google.com \
    --cc=salyzyn@android.com \
    --cc=sboyd@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=will.deacon@arm.com \
    --cc=will@kernel.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;
as well as URLs for NNTP newsgroup(s).