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Date:   Fri, 30 Aug 2019 16:43:33 +0800
From:   Gao Xiang <gaoxiang25@huawei.com>
To:     Dan Carpenter <dan.carpenter@oracle.com>
CC:     <devel@driverdev.osuosl.org>,
        Christoph Hellwig <hch@infradead.org>,
        Valdis =?gbk?Q?Kl=A8=A5tnieks?= <valdis.kletnieks@vt.edu>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <linux-kernel@vger.kernel.org>,
        Sasha Levin <alexander.levin@microsoft.com>,
        <linux-fsdevel@vger.kernel.org>,
        "OGAWA Hirofumi" <hirofumi@mail.parknet.co.jp>
Subject: Re: [PATCH] staging: exfat: add exfat filesystem code to staging
Message-ID: <20190830084333.GA193084@architecture4>
References: <20190829094136.GA28643@infradead.org>
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 <20190829151144.GJ23584@kadam>
 <20190829152757.GA125003@architecture4>
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 <20190829160441.GA141079@architecture4>
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Hi Dan,

On Fri, Aug 30, 2019 at 11:34:45AM +0300, Dan Carpenter wrote:
> On Fri, Aug 30, 2019 at 12:04:41AM +0800, Gao Xiang wrote:
> > Anyway, I'm fine to delete them all if you like, but I think majority of these
> > are meaningful.
> > 
> > data.c-		/* page is already locked */
> > data.c-		DBG_BUGON(PageUptodate(page));
> > data.c-
> > data.c:		if (unlikely(err))
> > data.c-			SetPageError(page);
> > data.c-		else
> > data.c-			SetPageUptodate(page);
> 
> If we cared about speed here then we would delete the DBG_BUGON() check
> because that's going to be expensive.  The likely/unlikely annotations
> should be used in places a reasonable person thinks it will make a
> difference to benchmarks.

DBG_BUGON will be a no-op ((void)x) in non-debugging mode,
I discussed related stuffs with Greg many months before [1] and
other filesystems also have similar functions...

p.s. I think we come to an agreement here...
I killed all unlikely/likely.

[1] http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2018-November/128951.html
sorry about no lore here.

Thanks,
Gao Xiang

> 
> regards,
> dan carpenter
>