DPDK patches and discussions
 help / color / mirror / Atom feed
From: Thomas Monjalon <thomas@monjalon.net>
To: Juraj Linkeš <juraj.linkes@pantheon.tech>,
	Ruifeng Wang <Ruifeng.Wang@arm.com>
Cc: "bruce.richardson@intel.com" <bruce.richardson@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"jerinj@marvell.com" <jerinj@marvell.com>,
	Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
	nd <nd@arm.com>
Subject: Re: [dpdk-dev] [PATCH] build: add -moutline-atomics to default Arm build
Date: Fri, 09 Oct 2020 08:52:58 +0200
Message-ID: <1936141.z0H9v2j6Xj@thomas> (raw)
In-Reply-To: <VI1PR0802MB2351477F94F0BBF79092156E9E080@VI1PR0802MB2351.eurprd08.prod.outlook.com>

09/10/2020 07:29, Ruifeng Wang:
> From: Thomas Monjalon <thomas@monjalon.net>
> > 01/10/2020 08:19, Juraj Linkeš:
> > > -moutline-atomics allows LSE instructions to be used if available when
> > > compiling for ARMv8.0 instruction set. It's enabled by default on
> > > newer compilers, such as gcc-10.1. Enable the option so that earlier
> > > compiler versions that support it but don't enable it by default build with it.
> > >
> > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > ---
> > >  machine_args_generic = [
> > > -	['default', ['-march=armv8-a+crc']],
> > > +	['default', ['-march=armv8-a+crc', '-moutline-atomics']],
> > >  	['native', ['-march=native']],
> > >  	['0xd03', ['-mcpu=cortex-a53']],
> > >  	['0xd04', ['-mcpu=cortex-a35']],
> > 
> > Why is it added only to the target "default"?
> > 
> Because 'default' target generates Armv8.0 instruction set which doesn't include LSE extension. 
> The flag enables LSE instructions when code runs on platforms that implements LSE extension.
> 
> For other targets, machine specific 'mcpu' or 'march' flags are used. LSE extension availability can be inferred from the given flags.
> So there is not need to add '-moutline-atomics' to them. 

OK
It's not obvious that the -mcpu flags implicitly include it.
What do you think adding such explanation in a v2?



  reply	other threads:[~2020-10-09  6:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-01  6:19 Juraj Linkeš
2020-10-06 20:14 ` Thomas Monjalon
2020-10-09  5:29   ` Ruifeng Wang
2020-10-09  6:52     ` Thomas Monjalon [this message]
2020-10-09  7:07       ` Ruifeng Wang
2020-10-09  9:50 ` [dpdk-dev] [PATCH v2] " Juraj Linkeš
2020-10-13 13:16   ` Thomas Monjalon

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=1936141.z0H9v2j6Xj@thomas \
    --to=thomas@monjalon.net \
    --cc=Honnappa.Nagarahalli@arm.com \
    --cc=Ruifeng.Wang@arm.com \
    --cc=bruce.richardson@intel.com \
    --cc=dev@dpdk.org \
    --cc=jerinj@marvell.com \
    --cc=juraj.linkes@pantheon.tech \
    --cc=nd@arm.com \
    /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

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ https://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git