From: Andrew Morton <akpm@linux-foundation.org>
To: Feng Tang <feng.tang@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
andi.kleen@intel.com, ying.huang@intel.com,
andriy.shevchenko@intel.com
Subject: Re: [RFC PATCH] makefile: add debug option to enable function aligned on 32 bytes
Date: Thu, 23 Jul 2020 17:57:04 -0700 [thread overview]
Message-ID: <20200723175704.44c4b890e76dc6dc68bf3674@linux-foundation.org> (raw)
In-Reply-To: <20200723062933.GA65362@shbuild999.sh.intel.com>
On Thu, 23 Jul 2020 14:29:33 +0800 Feng Tang <feng.tang@intel.com> wrote:
> > > gcc has an option '-falign-functions=n' to force text aligned, and with
> > > that option enabled, some of those performance changes will be gone,
> > > like [1][2][3].
> > >
> > > Add this option so that developers and 0day can easily find performance
> > > bump caused by text alignment change,
> >
> > Would they use it this way, or would they simply always enable the
> > option to reduce the variability?
>
> I may mis-understood it in my last reply. If you are asking about how
> will developers and 0day use this option, for 0day, I've talked with
> 0day folks, they may just enable it by default, as 0day cares more about
> the performance delta caused by a commit (Adding Philip and Rong from
> 0day).
OK, thanks, I suspected as much.
The patch is so simple and probably-will-work, I guess we toss it in
there and see.
However it would be good if the 0day people could use it for a while
and then provide some feedback on whether it is actually proving
useful. If not, we get to remove some stuff.
next prev parent reply other threads:[~2020-07-24 0:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 3:30 [RFC PATCH] makefile: add debug option to enable function aligned on 32 bytes Feng Tang
2020-07-23 3:39 ` Andrew Morton
2020-07-23 5:13 ` Feng Tang
2020-07-23 6:29 ` Feng Tang
2020-07-24 0:57 ` Andrew Morton [this message]
2020-07-24 1:06 ` Feng Tang
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