From mboxrd@z Thu Jan  1 00:00:00 1970
From: bsingharora@gmail.com (Balbir Singh)
Date: Sat, 27 Oct 2018 21:21:02 +1100
Subject: [PATCH 2/4] mm: speed up mremap by 500x on large regions (v2)
In-Reply-To: <20181025021350.GB13560@joelaf.mtv.corp.google.com>
References: <20181013013200.206928-1-joel@joelfernandes.org>
 <20181013013200.206928-3-joel@joelfernandes.org>
 <20181024101255.it4lptrjogalxbey@kshutemo-mobl1>
 <20181024115733.GN8537@350D>
 <20181025021350.GB13560@joelaf.mtv.corp.google.com>
List-ID: <linux-snps-arc@lists.infradead.org>
Message-ID: <20181027102102.GO8537@350D>
To: linux-snps-arc@lists.infradead.org

On Wed, Oct 24, 2018@07:13:50PM -0700, Joel Fernandes wrote:
> On Wed, Oct 24, 2018@10:57:33PM +1100, Balbir Singh wrote:
> [...]
> > > > +		pmd_t pmd;
> > > > +
> > > > +		new_ptl = pmd_lockptr(mm, new_pmd);
> > 
> > 
> > Looks like this is largely inspired by move_huge_pmd(), I guess a lot of
> > the code applies, why not just reuse as much as possible? The same comments
> > w.r.t mmap_sem helping protect against lock order issues applies as well.
> 
> I thought about this and when I looked into it, it seemed there are subtle
> differences that make such sharing not worth it (or not possible).
>

Could you elaborate on them?

Thanks,
Balbir Singh.