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From: Till Smejkal <till.smejkal@googlemail•com>
To: Matthew Wilcox <willy@infradead•org>
Cc: Till Smejkal <till.smejkal@googlemail•com>,
	Richard Henderson <rth@twiddle•net>,
	Ivan Kokshaysky <ink@jurassic•park.msu.ru>,
	Matt Turner <mattst88@gmail•com>,
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Subject: Re: [RFC PATCH 11/13] mm/vas: Introduce VAS segments - shareable address space regions
Date: Mon, 13 Mar 2017 15:45:36 -0700	[thread overview]
Message-ID: <20170313224536.saqdijtdayxwmlpz@arch-dev> (raw)
In-Reply-To: <20170313222758.GB4033@bombadil.infradead.org>

Hi Matthew,

On Mon, 13 Mar 2017, Matthew Wilcox wrote:
> On Mon, Mar 13, 2017 at 03:14:13PM -0700, Till Smejkal wrote:
> > +/**
> > + * Create a new VAS segment.
> > + *
> > + * @param[in] name:		The name of the new VAS segment.
> > + * @param[in] start:		The address where the VAS segment begins.
> > + * @param[in] end:		The address where the VAS segment ends.
> > + * @param[in] mode:		The access rights for the VAS segment.
> > + *
> > + * @returns:			The VAS segment ID on success, -ERRNO otherwise.
> > + **/
> 
> Please follow the kernel-doc conventions, as described in
> Documentation/doc-guide/kernel-doc.rst.  Also, function documentation
> goes with the implementation, not the declaration.

Thank you for this pointer. I wasn't aware of this convention. I will change the
patches accordingly.

> > +/**
> > + * Get ID of the VAS segment belonging to a given name.
> > + *
> > + * @param[in] name:		The name of the VAS segment for which the ID
> > + *				should be returned.
> > + *
> > + * @returns:			The VAS segment ID on success, -ERRNO
> > + *				otherwise.
> > + **/
> > +extern int vas_seg_find(const char *name);
> 
> So ... segments have names, and IDs ... and access permissions ...
> Why isn't this a special purpose filesystem?

We also thought about this. However, we decided against implementing them as a
special purpose filesystem, mainly because we could not think of a good way to
represent a VAS/VAS segment in this file system (should they be represented rather as
file or directory) and we weren't sure what a hierarchy in the filesystem would mean
for the underlying address spaces. Hence we decided against it and rather used a
combination of IDR and sysfs. However, I don't have any strong feelings and would
also reimplement them as a special purpose filesystem if people rather like them to
be one.

Till

  reply	other threads:[~2017-03-13 22:45 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-13 22:14 [RFC PATCH 00/13] Introduce first class virtual address spaces Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 01/13] mm: Add mm_struct argument to 'mmap_region' Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 02/13] mm: Add mm_struct argument to 'do_mmap' and 'do_mmap_pgoff' Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 03/13] mm: Rename 'unmap_region' and add mm_struct argument Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 04/13] mm: Add mm_struct argument to 'get_unmapped_area' and 'vm_unmapped_area' Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 05/13] mm: Add mm_struct argument to 'mm_populate' and '__mm_populate' Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 06/13] mm/mmap: Export 'vma_link' and 'find_vma_links' to mm subsystem Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 07/13] kernel/fork: Split and export 'mm_alloc' and 'mm_init' Till Smejkal
2017-03-14 10:18   ` David Laight
2017-03-14 16:18     ` Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 08/13] kernel/fork: Define explicitly which mm_struct to duplicate during fork Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 09/13] mm/memory: Add function to one-to-one duplicate page ranges Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 10/13] mm: Introduce first class virtual address spaces Till Smejkal
2017-03-13 23:52   ` Greg Kroah-Hartman
2017-03-14  0:24     ` Till Smejkal
2017-03-14  1:35   ` Vineet Gupta
2017-03-14  2:34     ` Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 11/13] mm/vas: Introduce VAS segments - shareable address space regions Till Smejkal
2017-03-13 22:27   ` Matthew Wilcox
2017-03-13 22:45     ` Till Smejkal [this message]
2017-03-13 22:14 ` [RFC PATCH 12/13] mm/vas: Add lazy-attach support for first class virtual address spaces Till Smejkal
2017-03-13 22:14 ` [RFC PATCH 13/13] fs/proc: Add procfs " Till Smejkal
2017-03-14  0:18 ` [RFC PATCH 00/13] Introduce " Richard Henderson
2017-03-14  0:39   ` Till Smejkal
2017-03-14  1:02     ` Richard Henderson
2017-03-14  1:31       ` Till Smejkal
2017-03-14  0:58 ` Andy Lutomirski
2017-03-14  2:07   ` Till Smejkal
2017-03-14  5:37     ` Andy Lutomirski
2017-03-14 16:12       ` Till Smejkal
2017-03-14 19:53         ` Chris Metcalf
2017-03-14 21:14           ` Till Smejkal
2017-03-15 16:51         ` Andy Lutomirski
2017-03-15 16:57           ` Matthew Wilcox
2017-03-15 19:44           ` Till Smejkal
2017-03-15 19:47             ` Rich Felker
2017-03-15 21:30               ` Till Smejkal
2017-03-15 20:06             ` Andy Lutomirski
2017-03-15 22:02               ` Till Smejkal
2017-03-15 22:09                 ` Luck, Tony
2017-03-15 23:18                   ` Till Smejkal
2017-03-16  8:21                 ` Thomas Gleixner
2017-03-16 17:29                   ` Till Smejkal
2017-03-16 17:42                     ` Thomas Gleixner
2017-03-16 17:50                       ` Till Smejkal

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