From: Rusty Russell <rusty@rustcorp.com.au>
To: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@suse.de>,
Stewart Smith <stewart@flamingspork.com>,
linux-mm@kvack.org, linux-arch@vger.kernel.org
Subject: Re: [patch 1/2] mm: fincore()
Date: Sat, 16 Feb 2013 14:53:43 +1030 [thread overview]
Message-ID: <87621skhtc.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20130215154235.0fb36f53.akpm@linux-foundation.org>
Andrew Morton <akpm@linux-foundation.org> writes:
> On Fri, 15 Feb 2013 18:13:04 -0500
> Johannes Weiner <hannes@cmpxchg.org> wrote:
>> I dunno. The byte vector might not be optimal but its worst cases
>> seem more attractive, is just as extensible, and dead simple to use.
>
> But I think "which pages from this 4TB file are in core" will not be an
> uncommon usage, and writing a gig of memory to find three pages is just
> awful.
Actually, I don't know of any usage for this call.
I'd really like to use it for backup programs, so they stop pulling
random crap into memory (but leave things already resident). But that
needs to madvise(MADV_DONTNEED) on the page, so need mmap.
So why not just use mincore?
Cheers,
Rusty.
next prev parent reply other threads:[~2013-02-17 22:15 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-11 3:13 RFC: mincore: add a bit to indicate a page is dirty Rusty Russell
2013-02-11 16:27 ` Johannes Weiner
2013-02-11 22:12 ` Andrew Morton
2013-02-12 5:44 ` Rusty Russell
2013-02-15 6:34 ` [patch 1/2] mm: fincore() Johannes Weiner
2013-02-15 20:39 ` David Miller
2013-02-15 21:14 ` Andrew Morton
2013-02-15 22:28 ` Johannes Weiner
2013-02-15 22:34 ` Andrew Morton
2013-02-15 21:27 ` Andrew Morton
2013-02-15 23:13 ` Johannes Weiner
2013-02-15 23:42 ` Andrew Morton
2013-02-16 4:23 ` Rusty Russell [this message]
2013-02-17 22:51 ` Johannes Weiner
2013-02-17 22:54 ` Andrew Morton
2013-05-29 14:53 ` Andres Freund
2013-05-29 17:32 ` Johannes Weiner
2013-05-29 17:52 ` Andres Freund
2013-02-18 5:41 ` Rusty Russell
2013-02-19 10:25 ` Simon Jeons
2013-02-15 6:35 ` [patch 2/2] x86-64: hook up fincore() syscall Johannes Weiner
2013-02-12 5:49 ` RFC: mincore: add a bit to indicate a page is dirty Rusty Russell
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