* module references
@ 2005-11-23 2:58 Hollis Blanchard
2005-11-23 12:33 ` Marco Gerards
0 siblings, 1 reply; 6+ messages in thread
From: Hollis Blanchard @ 2005-11-23 2:58 UTC (permalink / raw)
To: The development of GRUB 2
Right now I'm getting a lot of these:
../fs/affs.c: In function `grub_mod_init':
../fs/affs.c:556: warning: unused parameter `mod'
... in fact, one for every GRUB_MOD_INIT in fs/ and partmap/, it seems.
This led me to examine the module reference counting system. Most
filesystems don't do anything more than set a "my_mod" global variable,
and never use it. fat.c, on the other hand, seems to actually be trying
to use a refcount.
Are modules ever automatically unloaded? When? If so, we need a lot
more reference counting. If not, we've got some unnecessary complexity
we should remove.
-Hollis
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: module references
2005-11-23 2:58 module references Hollis Blanchard
@ 2005-11-23 12:33 ` Marco Gerards
2005-11-23 22:46 ` Hollis Blanchard
0 siblings, 1 reply; 6+ messages in thread
From: Marco Gerards @ 2005-11-23 12:33 UTC (permalink / raw)
To: The development of GRUB 2
Hollis Blanchard <hollis@penguinppc.org> writes:
> Right now I'm getting a lot of these:
> ../fs/affs.c: In function `grub_mod_init':
> ../fs/affs.c:556: warning: unused parameter `mod'
> ... in fact, one for every GRUB_MOD_INIT in fs/ and partmap/, it seems.
Right. `my_mod' is used by the filesystems, but not used from INIT.
> This led me to examine the module reference counting system. Most
> filesystems don't do anything more than set a "my_mod" global
> variable, and never use it. fat.c, on the other hand, seems to
> actually be trying to use a refcount.
They do use it. When opening a file the reference is increased so the
user can't remove the filesystem module until the file is closed. If
this is not implemented this way, it's a bug.
> Are modules ever automatically unloaded? When? If so, we need a lot
> more reference counting. If not, we've got some unnecessary complexity
> we should remove.
It's done so you can not remove a module that is in use by GRUB or
another module. For example when you open a file for a long time.
--
Marco
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: module references
2005-11-23 12:33 ` Marco Gerards
@ 2005-11-23 22:46 ` Hollis Blanchard
2005-11-24 6:23 ` Vesa Jääskeläinen
0 siblings, 1 reply; 6+ messages in thread
From: Hollis Blanchard @ 2005-11-23 22:46 UTC (permalink / raw)
To: The development of GRUB 2
On Nov 23, 2005, at 6:33 AM, Marco Gerards wrote:
>
>> Are modules ever automatically unloaded? When? If so, we need a lot
>> more reference counting. If not, we've got some unnecessary complexity
>> we should remove.
>
> It's done so you can not remove a module that is in use by GRUB or
> another module. For example when you open a file for a long time.
Please describe for me how I can trigger this bug. In other words, what
commands can I run to unload a filesystem module while a file is open?
-Hollis
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: module references
2005-11-23 22:46 ` Hollis Blanchard
@ 2005-11-24 6:23 ` Vesa Jääskeläinen
2005-11-24 7:28 ` Marco Gerards
0 siblings, 1 reply; 6+ messages in thread
From: Vesa Jääskeläinen @ 2005-11-24 6:23 UTC (permalink / raw)
To: The development of GRUB 2
Hollis Blanchard wrote:
> On Nov 23, 2005, at 6:33 AM, Marco Gerards wrote:
>>
>>> Are modules ever automatically unloaded? When? If so, we need a lot
>>> more reference counting. If not, we've got some unnecessary complexity
>>> we should remove.
>>
>> It's done so you can not remove a module that is in use by GRUB or
>> another module. For example when you open a file for a long time.
>
> Please describe for me how I can trigger this bug. In other words, what
> commands can I run to unload a filesystem module while a file is open?
One way at least is to use font subsystem. That at least keeps file open.
See guide from Okuji's message how to create font file and:
insmod font
font .../fontfile.pff
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: module references
2005-11-24 6:23 ` Vesa Jääskeläinen
@ 2005-11-24 7:28 ` Marco Gerards
2005-11-24 7:57 ` Vesa Jääskeläinen
0 siblings, 1 reply; 6+ messages in thread
From: Marco Gerards @ 2005-11-24 7:28 UTC (permalink / raw)
To: The development of GRUB 2
Vesa Jääskeläinen <chaac@nic.fi> writes:
>> Please describe for me how I can trigger this bug. In other words, what
>> commands can I run to unload a filesystem module while a file is open?
>
> One way at least is to use font subsystem. That at least keeps file open.
>
> See guide from Okuji's message how to create font file and:
>
> insmod font
> font .../fontfile.pff
Shouldn't the font file be opened, loaded into memory and closed?
--
Marco
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: module references
2005-11-24 7:28 ` Marco Gerards
@ 2005-11-24 7:57 ` Vesa Jääskeläinen
0 siblings, 0 replies; 6+ messages in thread
From: Vesa Jääskeläinen @ 2005-11-24 7:57 UTC (permalink / raw)
To: The development of GRUB 2
Marco Gerards wrote:
> Vesa Jääskeläinen <chaac@nic.fi> writes:
>
>>> Please describe for me how I can trigger this bug. In other words, what
>>> commands can I run to unload a filesystem module while a file is open?
>> One way at least is to use font subsystem. That at least keeps file open.
>>
>> See guide from Okuji's message how to create font file and:
>>
>> insmod font
>> font .../fontfile.pff
>
> Shouldn't the font file be opened, loaded into memory and closed?
Not at this time :)
Perhaps in the future...
But in reality, memory requirements for whole Unicode map is quite big.
So loading only parts that really matter, saves quite a lot.
If you look at the code there is TODO with similar commend "caching
needed" :)
If we think about my problem with fonts (or reading them), I didn't even
try to make workaround like caching everything. Instead I wanted to find
root cause for the reading problem. So this has slowed down a bit
development.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2005-11-24 7:57 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-11-23 2:58 module references Hollis Blanchard
2005-11-23 12:33 ` Marco Gerards
2005-11-23 22:46 ` Hollis Blanchard
2005-11-24 6:23 ` Vesa Jääskeläinen
2005-11-24 7:28 ` Marco Gerards
2005-11-24 7:57 ` Vesa Jääskeläinen
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