Re: [PATCHv2] isdn: reduce stack size of mISDN_dsp

From: Karsten Keil
Date: Sun Mar 01 2009 - 14:55:06 EST


On Sun, Mar 01, 2009 at 06:10:24PM +0100, Frank Seidel wrote:
> From: Frank Seidel <frank@xxxxxxxxxxx>
>
> Reduce stack size memory footprint of mISDN_dsp.
> (From 1468 bytes for dsp_cmx_send on i386 down
> to 44).

Looks safer and has the same function as before, but
I think we should work on a better solution later, which
use one buffer per instance and allocate it on creation time.
Andreas, what do you think ?

>
> Signed-off-by: Frank Seidel <frank@xxxxxxxxxxx>
> ---
> drivers/isdn/mISDN/dsp_cmx.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> --- a/drivers/isdn/mISDN/dsp_cmx.c
> +++ b/drivers/isdn/mISDN/dsp_cmx.c
> @@ -1592,13 +1592,21 @@ dsp_cmx_send(void *arg)
> struct dsp_conf_member *member;
> struct dsp *dsp;
> int mustmix, members;
> - s32 mixbuffer[MAX_POLL+100], *c;
> + s32 *mixbuffer;
> + s32 *c;
> u8 *p, *q;
> int r, rr;
> int jittercheck = 0, delay, i;
> u_long flags;
> u16 length, count;
>
> + mixbuffer = kmalloc(sizeof(*mixbuffer) * (MAX_POLL + 100), GFP_KERNEL);
> + if (!mixbuffer) {
> + printk(KERN_ERR "mISDN_dsp: cannot allocate buffer(%s)\n",
> + __func__);
> + return;
> + }
> +
> /* lock */
> spin_lock_irqsave(&dsp_lock, flags);
>
> @@ -1811,6 +1819,8 @@ dsp_cmx_send(void *arg)
>
> /* unlock */
> spin_unlock_irqrestore(&dsp_lock, flags);
> +
> + kfree(mixbuffer);
> }
>
> /*

--
Karsten Keil
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