From: Mike Kravetz <mike.kravetz@oracle.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Cheng Li <lic121@chinatelecom.cn>,
akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: use mem_map_offset instead of mem_map_next
Date: Tue, 6 Sep 2022 10:04:52 -0700 [thread overview]
Message-ID: <Yxd9tA8ThZtB77dq@monkey> (raw)
In-Reply-To: <YxUVZpsmukNW5NyK@casper.infradead.org>
On 09/04/22 22:15, Matthew Wilcox wrote:
> On Sun, Sep 04, 2022 at 02:02:41PM +0000, Cheng Li wrote:
> > To handle discontiguity case, mem_map_next() has a parameter named
> > `offset`. As a function caller, one would be confused why "get
> > next entry" needs a parameter named "offset". The other drawback of
> > mem_map_next() is that the callers must take care of the map between
> > parameter "iter" and "offset", otherwise we may get an hole or
> > duplication during iteration. So we use mem_map_offset instead of
> > mem_map_next.
>
> I think we should go further and get rid of mem_map_offset().
> nth_page() is now more efficient than mem_map_offset().
Agree.
However, IIUC nth_page() will 'almost' always be more efficient. The
only exception is unlikely configuration where CONFIG_SPARSEMEM &&
!CONFIG_SPARSEMEM_VMEMMAP. Correct?
Not arguing against replacement. Just wanting to refresh my memory.
--
Mike Kravetz
prev parent reply other threads:[~2022-09-06 17:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-04 14:02 Cheng Li
2022-09-04 16:38 ` kernel test robot
2022-09-04 17:00 ` kernel test robot
2022-09-04 21:15 ` Matthew Wilcox
2022-09-06 17:04 ` Mike Kravetz [this message]
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