linux-kernel - Re: [PATCH v10 3/3] mm: add anonymous vma name refcounting

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Message-ID: <20211007084120.GB15698@duo.ucw.cz>
Date:   Thu, 7 Oct 2021 10:41:20 +0200
From:   Pavel Machek <pavel@....cz>
To:     Michal Hocko <mhocko@...e.com>
Cc:     Suren Baghdasaryan <surenb@...gle.com>,
        David Hildenbrand <david@...hat.com>,
        John Hubbard <jhubbard@...dia.com>,
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Subject: Re: [PATCH v10 3/3] mm: add anonymous vma name refcounting

Hi!

> [...]
> > > That "central facility" option can be as simple as "mkdir
> > > /somewhere/sanitized_id", using inode numbers for example. You don't
> > > really need IPC.
> > 
> > Hmm, so the suggestion is to have some directory which contains files
> > representing IDs, each containing the string name of the associated
> > vma? Then let's say we are creating a new VMA and want to name it. We
> > would have to scan that directory, check all files and see if any of
> > them contain the name we want to reuse the same ID.
> 
> I believe Pavel meant something as simple as
> $ YOUR_FILE=$YOUR_IDS_DIR/my_string_name
> $ touch $YOUR_FILE
> $ stat -c %i $YOUR_FILE
> 
> YOUR_IDS_DIR can live on a tmpfs and you can even implement a policy on
> top of that (who can generate new ids, gurantee uniqness etc...).
> 
> The above is certainly not for free of course but if you really need a
> system wide consistency when using names then you need some sort of
> central authority. How you implement that is not all that important
> but I do not think we want to handle that in the kernel.

For the record, yes, that is what I meant.

Thanks,
								Pavel
-- 
http://www.livejournal.com/~pavelmachek

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