lkml.org 
[lkml]   [2012]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 3/8] procfs: Add ability to plug in auxiliary fdinfo providers
On 08/14/2012 06:03 PM, Cyrill Gorcunov wrote:
> This patch brings ability to plug in auxiliary fdinfo providers.
> For example in further patches eventfd, evenpoll and fsnotify
> will print out information associated with files.
>
> This feature is CONFIG_CHECKPOINT_RESTORE guarded to eliminate
> overhead for those who don't need it at all (this
> unfortunately makes patch bigger than I wanted).
>
> The basic usage rule is the following
>
> - fdinfo provider should register own "show" method
> via proc_register_fdinfo_driver call, where "show"
> methods are rather well known seq-file operations
>
> - once the kernel opens /proc/$pid/fdinfo/$fd file
> it calls for ->probe() method in registered fdinfo
> drivers, and if probe success, then seq-file "show"
> operations will be called to provide out additional
> infomation
>
> Initially we considered to inject some "show" metod to
> file_operations but since there really a number of
> file_operations declared inside kernel (and in real the
> further patches cover onle eventfd/epoll/inotify) the
> waste of memory space will be inacceptable I think.
>
> Pavel, I've left seq_next memthod as it was simply because
> we can't leave seq_next() after calling extra->driver->ops->start
> without increasing "pos", thus we need to call for "show" manually
> once.
>
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> CC: Al Viro <viro@ZenIV.linux.org.uk>
> CC: Alexey Dobriyan <adobriyan@gmail.com>
> CC: Andrew Morton <akpm@linux-foundation.org>
> CC: Pavel Emelyanov <xemul@parallels.com>
> CC: James Bottomley <jbottomley@parallels.com>

Acked-by: Pavel Emelyanov <xemul@parallels.com>



\
 
 \ /
  Last update: 2012-08-14 17:03    [W:0.123 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site