From: Dave Chinner <david@fromorbit.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>, Mel Gorman <mgorman@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
xfs@oss.sgi.com, ppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur
Date: Mon, 9 Mar 2015 22:29:36 +1100 [thread overview]
Message-ID: <20150309112936.GD26657@destitution> (raw)
In-Reply-To: <CA+55aFyQyZXu2fi7X9bWdSX0utk8=sccfBwFaSoToROXoE_PLA@mail.gmail.com>
On Sun, Mar 08, 2015 at 11:35:59AM -0700, Linus Torvalds wrote:
> On Sun, Mar 8, 2015 at 3:02 AM, Ingo Molnar <mingo@kernel.org> wrote:
> But:
>
> > As a second hack (not to be applied), could we change:
> >
> > #define _PAGE_BIT_PROTNONE _PAGE_BIT_GLOBAL
> >
> > to:
> >
> > #define _PAGE_BIT_PROTNONE (_PAGE_BIT_GLOBAL+1)
> >
> > to double check that the position of the bit does not matter?
>
> Agreed. We should definitely try that.
>
> Dave?
As Mel has already mentioned, I'm in Boston for LSFMM and don't have
access to the test rig I've used to generate this.
> Also, is there some sane way for me to actually see this behavior on a
> regular machine with just a single socket? Dave is apparently running
> in some fake-numa setup, I'm wondering if this is easy enough to
> reproduce that I could see it myself.
Should be - I don't actually use 500TB of storage to generate this -
50GB on an SSD is all you need from the storage side. I just use a
sparse backing file to make it look like a 500TB device. :P
i.e. create an XFS filesystem on a 500TB sparse file with "mkfs.xfs
-d size=500t,file=1 /path/to/file.img", mount it on loopback or as a
virtio,cache=none device for the guest vm and then use fsmark to
generate several million files spread across many, many directories
such as:
$ fs_mark -D 10000 -S0 -n 100000 -s 1 -L 32 -d \
/mnt/scratch/0 -d /mnt/scratch/1 -d /mnt/scratch/2 -d \
/mnt/scratch/3 -d /mnt/scratch/4 -d /mnt/scratch/5 -d \
/mnt/scratch/6 -d /mnt/scratch/7
That should only take a few minutes to run - if you throw 8p at it
then it should run at >100k files/s being created.
Then unmount and run "xfs_repair -o bhash=101703 /path/to/file.img"
on the resultant image file.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2015-03-09 11:29 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-07 15:20 [RFC PATCH 0/4] Automatic NUMA balancing and PROT_NONE handling followup v2r8 Mel Gorman
2015-03-07 15:20 ` [PATCH 1/4] mm: thp: Return the correct value for change_huge_pmd Mel Gorman
2015-03-07 20:13 ` Linus Torvalds
2015-03-07 20:31 ` Linus Torvalds
2015-03-07 20:56 ` Mel Gorman
2015-03-07 15:20 ` [PATCH 2/4] mm: numa: Remove migrate_ratelimited Mel Gorman
2015-03-07 15:20 ` [PATCH 3/4] mm: numa: Mark huge PTEs young when clearing NUMA hinting faults Mel Gorman
2015-03-07 18:33 ` Linus Torvalds
2015-03-07 18:42 ` Linus Torvalds
2015-03-07 15:20 ` [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur Mel Gorman
2015-03-07 16:36 ` Ingo Molnar
2015-03-07 17:37 ` Mel Gorman
2015-03-08 9:54 ` Ingo Molnar
2015-03-07 19:12 ` Linus Torvalds
2015-03-08 10:02 ` Ingo Molnar
2015-03-08 18:35 ` Linus Torvalds
2015-03-08 18:46 ` Linus Torvalds
2015-03-09 11:29 ` Dave Chinner [this message]
2015-03-09 16:52 ` Linus Torvalds
2015-03-09 19:19 ` Dave Chinner
2015-03-10 23:55 ` Linus Torvalds
2015-03-12 13:10 ` Mel Gorman
2015-03-12 16:20 ` Linus Torvalds
2015-03-12 18:49 ` Mel Gorman
2015-03-17 7:06 ` Dave Chinner
2015-03-17 16:53 ` Linus Torvalds
2015-03-17 20:51 ` Dave Chinner
2015-03-17 21:30 ` Linus Torvalds
2015-03-17 22:08 ` Dave Chinner
2015-03-18 16:08 ` Linus Torvalds
2015-03-18 17:31 ` Linus Torvalds
2015-03-18 22:23 ` Dave Chinner
2015-03-19 14:10 ` Mel Gorman
2015-03-19 18:09 ` Linus Torvalds
2015-03-19 21:41 ` Linus Torvalds
2015-03-19 22:41 ` Dave Chinner
2015-03-19 23:05 ` Linus Torvalds
2015-03-19 23:23 ` Dave Chinner
2015-03-20 0:23 ` Dave Chinner
2015-03-20 1:29 ` Linus Torvalds
2015-03-20 4:13 ` Dave Chinner
2015-03-20 17:02 ` Linus Torvalds
2015-03-23 12:01 ` Mel Gorman
2015-03-20 10:12 ` Mel Gorman
2015-03-20 9:56 ` Mel Gorman
2015-03-08 20:40 ` Mel Gorman
2015-03-09 21:02 ` Mel Gorman
2015-03-10 13:08 ` Mel Gorman
2015-03-08 9:41 ` Ingo Molnar
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