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From: Stephen Hemminger <stephen@networkplumber.org>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: Dharmik Thakkar <dharmik.thakkar@arm.com>,
	dev@dpdk.org, nd@arm.com, ruifeng.wang@arm.com,
	david.marchand@redhat.com
Subject: Re: [dpdk-dev] [PATCH] checkpatch: enable volatile warning
Date: Wed, 10 Mar 2021 07:10:49 -0800	[thread overview]
Message-ID: <20210310071017.157a4105@hermes.local> (raw)
In-Reply-To: <62130884.hdUCYtv3VG@thomas>

On Wed, 10 Mar 2021 12:10:01 +0100
Thomas Monjalon <thomas@monjalon.net> wrote:

> 10/03/2021 12:04, Dharmik Thakkar:
> > Enable volatile considered harmful warning since use of volatile
> > is suspect.
> > 
> > Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
> > Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>  
> 
> git grep -w volatile | wc -l
> 	1796
> 
> How much is it suspect?
> 
> 

Many seem to be unsafe.
   testpmd: uses flags values in unsafe manner
      it also uses volatile when accessing hardware registers

   test-alarm is expecting that alarm() is a signal
       (it is not)

   test-atomic is ok
   test-barrier is doing barriers and not using __atomic

   drivers use volatile to mark hardware registers.

It is still true volatile is not enough are not weak memory model.

  reply	other threads:[~2021-03-10 15:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-10 11:04 Dharmik Thakkar
2021-03-10 11:10 ` Thomas Monjalon
2021-03-10 15:10   ` Stephen Hemminger [this message]
2021-08-16 13:28     ` Dharmik Thakkar

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