Re: [PATCH][TRIVIAL] Allocate kprobe_table at runtime

Re: [PATCH][TRIVIAL] Allocate kprobe_table at runtime

[Andi Kleen]

Prasanna S Panchamukhi <prasanna@in.ibm.com> writes:

> Jeff,
> 
> On Sun, Jun 26, 2005 at 06:37:29PM +0000, Jeff Sipek wrote:
> > Allocates kprobe_table at runtime.
> > -	/* FIXME allocate the probe table, currently defined statically */
> > +	kprobe_table = kmalloc(sizeof(struct hlist_head)*KPROBE_TABLE_SIZE, GFP_ATOMIC);
> 
> Memory allocation using GFP_KERNEL has more chances of success as compared to
> GFP_ATOMIC. Why can't we use GFP_KERNEL here?

I don't see any sense in the change anyways. Just using BSS 
should be fine.

Jeff, when you submit a patch you should add a small blurb
describing why you think it is a good idea.

-Andi

[PATCH v2][TRIVIAL] Allocate kprobe_table at runtime

[Jeff Sipek]

[-- Attachment #1: Type: text/plain, Size: 1420 bytes --]

On Mon, Jun 27, 2005 at 08:14:12AM +0200, Andi Kleen wrote:
> Prasanna S Panchamukhi <prasanna@in.ibm.com> writes:
> 
> > Jeff,
> > 
> > On Sun, Jun 26, 2005 at 06:37:29PM +0000, Jeff Sipek wrote:
> > > Allocates kprobe_table at runtime.
> > > -	/* FIXME allocate the probe table, currently defined statically */
> > > +	kprobe_table = kmalloc(sizeof(struct hlist_head)*KPROBE_TABLE_SIZE, GFP_ATOMIC);
> > 
> > Memory allocation using GFP_KERNEL has more chances of success as compared to
> > GFP_ATOMIC. Why can't we use GFP_KERNEL here?
> 
> I don't see any sense in the change anyways. Just using BSS 
> should be fine.
> 
> Jeff, when you submit a patch you should add a small blurb
> describing why you think it is a good idea.

That patch was somewhat impulsive...I was looking at some code and saw a
FIXME that required minimal work. I agree that BSS is good enough.

Patch below removes the FIXME notice.

Pick one ;-) (Patch Monkey is CC'd).

Jeff.


Remove useless FIXME.

Signed-off-by: Josef "Jeff" Sipek

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -261,7 +261,6 @@ static int __init init_kprobes(void)
 {
 	int i, err = 0;
 
-	/* FIXME allocate the probe table, currently defined statically */
 	/* initialize all list heads */
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++)
 		INIT_HLIST_HEAD(&kprobe_table[i]);

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 189 bytes --]

Re: [PATCH v2][TRIVIAL] Allocate kprobe_table at runtime

[Luca Falavigna]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

> I agree that BSS is good enough.

Alternatively, you can implement dynamic allocation of each element of
kprobe_table in register_kprobe function. You will be able to free them by
calling unregister_kprobe function later on.

Regards,
- --
					Luca
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iQEVAwUBQsBY/8zkDT3RfMB6AQJBGQf+PUMdOIpAfq4Q5lI77P7uSx1vdq2905Dp
UwowzJpBLhQoZWI94xmhp7zx2unu5IqKBoXl62sjqOLgT9/K417ReEKFKfN3SSex
shtulBOFxHfimNZX1mYhtmgJxKMU3jb3jyjXQg4oufL15Khl5PqkIxWewcVGB8LB
bciH1242moxl7jKmEJXqm8IU4ZezOpfRoBYnvaxVrr1zL/zQzUgISgBfb2GkYpSP
ErXg+w8ggUJ/TDlkZyGjT1OmjhLmb1ekYxzUE/K+dYnP5GGC/sGx5t/YgLxiKXjL
nfNM7oF8qP43eArFmbQlUpMAXpkCWOGr7v5Ifcq8hJRfo99B9GL5uA==
=fBGJ
-----END PGP SIGNATURE-----