Re: [PATCH] vfs: keep inodes with page cache off the inode shrinker LRU

[Russell King - ARM Linux admin]

On Tue, Feb 11, 2020 at 05:03:02PM -0800, Linus Torvalds wrote:
> On Tue, Feb 11, 2020 at 4:47 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > What's the situation with highmem on ARM?
> 
> Afaik it's exactly the same as highmem on x86 - only 32-bit ARM ever
> needed it, and I was ranting at some people for repeating all the
> mistakes Intel did.
> 
> But arm64 doesn't need it, and while 32-bit arm is obviosuly still
> selling, I think that in many ways the switch-over to 64-bit has been
> quicker on ARM than it was on x86. Partly because it happened later
> (so all the 64-bit teething pains were dealt with), but largely
> because everybody ended up actively discouraging 32-bit on the Android
> side.
> 
> There were a couple of unfortunate early 32-bit arm server attempts,
> but they were - predictably - complete garbage and nobody bought them.
> They don't exist any more.
> 
> So at least my gut feel is that the arm people don't have any big
> reason to push for maintaining HIGHMEM support either.
> 
> But I'm adding a couple of arm people and the arm list just in case
> they have some input.
> 
> [ Obvious background for newly added people: we're talking about
> making CONFIG_HIGHMEM a deprecated feature and saying that if you want
> to run with lots of memory on a 32-bit kernel, you're doing legacy
> stuff and can use a legacy kernel ]

Well, the recent 32-bit ARM systems generally have more than 1G
of memory, so make use of highmem as a rule.  You're probably
talking about crippling support for any 32-bit ARM system produced
in the last 8 to 10 years.

-- 
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