linux-kernel - Re: [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls for FETCH-OP flavors

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Date:	Fri, 24 Jun 2016 12:35:36 -0700
From:	Davidlohr Bueso <dave@...olabs.net>
To:	KY Srinivasan <kys@...rosoft.com>
Cc:	James Bottomley <James.Bottomley@...senPartnership.com>,
	"peterz@...radead.org" <peterz@...radead.org>,
	"mingo@...nel.org" <mingo@...nel.org>,
	"davem@...emloft.net" <davem@...emloft.net>,
	"cw00.choi@...sung.com" <cw00.choi@...sung.com>,
	"dougthompson@...ssion.com" <dougthompson@...ssion.com>,
	"bp@...en8.de" <bp@...en8.de>,
	"mchehab@....samsung.com" <mchehab@....samsung.com>,
	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	"pfg@....com" <pfg@....com>, "jikos@...nel.org" <jikos@...nel.org>,
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	"sumit.semwal@...aro.org" <sumit.semwal@...aro.org>,
	"schwidefsky@...ibm.com" <schwidefsky@...ibm.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls
 for FETCH-OP flavors

On Fri, 24 Jun 2016, KY Srinivasan wrote:

>How so? Can you expand on the racy part. The subtraction is done on a local copy of
>the value.

Yeah, you're right. I took a look at the generated code and I was unnecessarily worried
about the window between the return value and the subtraction.

Thanks,
Davidlohr