カテゴリ: 英語

I've been mulling for some time to just remove non linear mappings.
AFAIK they were only useful on 32bit and are obsolete and could be
emulated with VMAs instead.

mull: 熟慮する

だけど、日本語のニュアンス的には non linear mappingのコードを消すかどうかをずっと




I have family, who need peaceful life without being finger-pointed at their back....


英語では to talk about someone behind their back が辞書に載っている慣用句ですが、文字通り後ろ指を指すという表現をご近所のネイティブのお爺さんが言っておりました。


Just a moment! は、『待てこら!』『ちょおっとまったあああ!』という意味で、ゆのかさんの使い方はネイティブと言えます。


Just a moment, folks. We are drifting out from our focus! 『みなさん、ちょっと待ってください。議題から逸れています』と会議で発言するとかっこいい。


Wait a minute! のほうが Just a moment! よりキツい感じ。後者は会議中に言われてもたいしてむっとしませんが、前者だと敵を作るかも。

ほむほむ。「マテやゴルァ(゚Д゚ )」か。だいたい分かった。勉強になるなー

Now I am paying for my naive assumption by sitting on the ankles.



さいきん、madvise()にいくつか追加があったのでman pageの査読をしている。
そのなかでHugh Dickinsが言った言葉

> @@ -221,8 +266,10 @@ for file access.

Oh, I absolutely agree with you, MAD_HWPOISON indeed;
but Andi might prefer MADV_HWPOISON.

そこに absolutely agree するのかよ :-)

Hi Dmitry,

> > > It looks like
> > >
> > > commit 7d930bc33653d5592dc386a76a38f39c2e962344
> > > Author: Johannes Berg
> > > Date: Tue Oct 20 15:08:53 2009 +0900
> > ...
> > > is causing oops on resume:
> >
> > There is a fix for this in my tree and I'll push it to Linus
> > tonight.
> Ah, even better ;) Thanks David.

and can we please stop jumping the gun here and going past the subsystem
maintainers. I think this happens a little bit too much lately.



jumping the gun でフライングの事。ここではサブシステムメンテナを飛び越えてパッチがマージされていく事に抗議している




まあ、ようするにDiscard Requestはまだまだ揉めていますよ。って事なんだけど

Hi Christoph,

(I've added Ccs, hoping for more expertise than we have in linux-mm.)

On Fri, 30 Oct 2009, Christoph Hellwig wrote:
> since 6a6ba83175c029c7820765bae44692266b29e67a the swap code
> unconditionally calls blkdev_issue_discard when swap clusters get freed.
> So far this was harmless because only the mtd driver has discard support
> wired up and it's pretty fast there (entirely done in-kernel).
> We're now adding support for real UNMAP/TRIM support for SCSI arrays and
> SSDs, and so far all the real life ones we've dealt with have too many
> performance issues to just issue the discard requests on the fly.
> Because of that unconditionally enabling this code is a bad idea, it
> really needs an option to disable it or even better just leave it
> disabled by default for now with an option to enable it.

Thanks for the info.

Yes, in practice TRIM seems a huge disappointment: is there a device on
which it is really implemented, and not more trouble than it's worth?

I'd been waiting for OCZ to get a Vertex 1.4* firmware out of Beta
before looking at swap discard again; but even then, the Linux ATA
support is still up in the air, so far as I know.

You don't mention swap's discard of the whole partition (or all
extents of the swapfile) at swapon time: do you believe that usage
is okay to retain? Is it likely on some devices to take so long,
that I ought to make it asynchronous?

Assuming that initial swap discard is good, I wonder whether just
to revert the discard of swap clusters for now: until such time as
we find devices (other than mtd) that can implement it efficiently.

If we do retain the discard of swap clusters, under something more
than an #if 0, any ideas for what I should make it conditional upon?

Something near /sys/block/sda/queue/rotational (nicely rw these days)
seems appropriate: any chance of a /sys/block/sda/queue/discard_is_useful?
I think I'd prefer that to a new option to swapon.

Or is there a sensible measurement I could make in swapfile.c: for
example, does discard of a range complete faster than write of the
same range? (But my guess is that those devices we'd want to avoid
discard on, would give erratic answers to any such test; never mind
the noise of what other I/Os are concurrent to the same device.)

Something I should almost certainly revert: at one stage I made the
non-rotational case spread its swapping evenly over the partition,
in case the device's wear-levelling was inadequate (localized).

But now I think it's better to ignore that possibility, and anchor
swapping to the start of the partition just as in the rotational case:
in the rotational case it's done to minimize seeking, in the non-
rotational case it would be to minimize encroaching upon that
initially discarded total extent.


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