* [QUOTA] Drop spin lock when calling request_module
@ 2003-11-05 11:10 Herbert Xu
2003-11-06 16:18 ` Jan Kara
0 siblings, 1 reply; 4+ messages in thread
From: Herbert Xu @ 2003-11-05 11:10 UTC (permalink / raw)
To: mvw, Linux Kernel Mailing List
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Hi:
This patch drops the spin lock when calling request_module as the
latter will sleep.
Cheers,
--
Debian GNU/Linux 3.0 is out! ( http://www.debian.org/ )
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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Index: kernel-source-2.5/fs/dquot.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/fs/dquot.c,v
retrieving revision 1.3
diff -u -r1.3 dquot.c
--- kernel-source-2.5/fs/dquot.c 26 Oct 2003 03:20:37 -0000 1.3
+++ kernel-source-2.5/fs/dquot.c 5 Nov 2003 11:04:30 -0000
@@ -128,17 +128,21 @@
if (!actqf || !try_module_get(actqf->qf_owner)) {
int qm;
+ spin_unlock(&dq_list_lock);
+
for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name)) {
actqf = NULL;
goto out;
}
+
+ spin_lock(&dq_list_lock);
for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
if (actqf && !try_module_get(actqf->qf_owner))
actqf = NULL;
}
-out:
spin_unlock(&dq_list_lock);
+out:
return actqf;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [QUOTA] Drop spin lock when calling request_module
2003-11-05 11:10 [QUOTA] Drop spin lock when calling request_module Herbert Xu
@ 2003-11-06 16:18 ` Jan Kara
2003-11-06 16:28 ` Linus Torvalds
0 siblings, 1 reply; 4+ messages in thread
From: Jan Kara @ 2003-11-06 16:18 UTC (permalink / raw)
To: Herbert Xu, torvalds, akpm; +Cc: Linux Kernel Mailing List
Hi,
> This patch drops the spin lock when calling request_module as the
> latter will sleep.
The patch looks right. Linus please apply if you find it serious
enough (or Andrew please queue it up for next releases...)...
Thanks
Honza
Index: kernel-source-2.5/fs/dquot.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/fs/dquot.c,v
retrieving revision 1.3
diff -u -r1.3 dquot.c
--- kernel-source-2.5/fs/dquot.c 26 Oct 2003 03:20:37 -0000 1.3
+++ kernel-source-2.5/fs/dquot.c 5 Nov 2003 11:04:30 -0000
@@ -128,17 +128,21 @@
if (!actqf || !try_module_get(actqf->qf_owner)) {
int qm;
+ spin_unlock(&dq_list_lock);
+
for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name)) {
actqf = NULL;
goto out;
}
+
+ spin_lock(&dq_list_lock);
for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
if (actqf && !try_module_get(actqf->qf_owner))
actqf = NULL;
}
-out:
spin_unlock(&dq_list_lock);
+out:
return actqf;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [QUOTA] Drop spin lock when calling request_module
2003-11-06 16:18 ` Jan Kara
@ 2003-11-06 16:28 ` Linus Torvalds
2003-11-06 18:11 ` Jan Kara
0 siblings, 1 reply; 4+ messages in thread
From: Linus Torvalds @ 2003-11-06 16:28 UTC (permalink / raw)
To: Jan Kara; +Cc: Herbert Xu, akpm, Linux Kernel Mailing List
On Thu, 6 Nov 2003, Jan Kara wrote:
> actqf = NULL;
> goto out;
Mind changing this to just a "return NULL" instead and just remove the
label entirely, now that it doesn't actually need to play with any
spinlocks?
I don't mind goto's if there is a _point_ to them, but this one doesn't
seem to fall under that heading.
Linus
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [QUOTA] Drop spin lock when calling request_module
2003-11-06 16:28 ` Linus Torvalds
@ 2003-11-06 18:11 ` Jan Kara
0 siblings, 0 replies; 4+ messages in thread
From: Jan Kara @ 2003-11-06 18:11 UTC (permalink / raw)
To: Linus Torvalds; +Cc: Herbert Xu, akpm, Linux Kernel Mailing List
>
> On Thu, 6 Nov 2003, Jan Kara wrote:
> > actqf = NULL;
> > goto out;
>
> Mind changing this to just a "return NULL" instead and just remove the
> label entirely, now that it doesn't actually need to play with any
> spinlocks?
>
> I don't mind goto's if there is a _point_ to them, but this one doesn't
> seem to fall under that heading.
You're right. The nicer fix is attached.
Honza
----------------------------Cut here--------------------------------------
diff -ruX ../kerndiffexclude linux-2.6.0-test9/fs/dquot.c linux-2.6.0-test9-loadfix/fs/dquot.c
--- linux-2.6.0-test9/fs/dquot.c Sat Oct 25 20:44:03 2003
+++ linux-2.6.0-test9-loadfix/fs/dquot.c Thu Nov 6 19:10:37 2003
@@ -128,16 +128,17 @@
if (!actqf || !try_module_get(actqf->qf_owner)) {
int qm;
+ spin_unlock(&dq_list_lock);
+
for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++);
- if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name)) {
- actqf = NULL;
- goto out;
- }
+ if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name))
+ return NULL;
+
+ spin_lock(&dq_list_lock);
for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next);
if (actqf && !try_module_get(actqf->qf_owner))
actqf = NULL;
}
-out:
spin_unlock(&dq_list_lock);
return actqf;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2003-11-06 18:11 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2003-11-05 11:10 [QUOTA] Drop spin lock when calling request_module Herbert Xu
2003-11-06 16:18 ` Jan Kara
2003-11-06 16:28 ` Linus Torvalds
2003-11-06 18:11 ` Jan Kara
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