On Mon, Mar 15, 2010 at 08:20:08PM +0100, Micha?? Nazarewicz wrote:
Each buffer is 4 pages and there are two such buffers in struct
fsg_common therefore the size of the structure is 9 pages.
I've been simply concerned about using kamlloc() for such big
structures so in the end decided to split it into 3 allocations.
Maybe I'm overeating though? Or maybe vmalloc() would solve those
problems? But then again, vmalloc() could degrade DMA performance
on systems w/o scatter-gather.
On Mon, 15 Mar 2010 20:28:13 +0100, Felipe Balbi <me@xxxxxxxxxxxxxxx> wrote:
I have no opinion anymore :-p
I can only think about the devices I've been working on which would be a
pain to allocate so much memory and would suffer if you use vmalloc()
too, so both would be a no-no for me :-p
So here it is... I think allocating buffers dynamically via kmalloc()
is the safest way. :)
bh = common->buffhds;
rc = -ENOMEM;
i = FSG_NUM_BUFFERS;
for(;;) {
bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
if (unlikely(!bh->buf))
goto error_release;
if (!--i)
break;
bh->next = bh + 1;
++bh;
}
bh->next = common->buffhds;
how about ?
for (i = FSG_NUM_BUFFER; i; i--, ++bh) {
bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
if (!bh->buf)
goto error_release;
}
bh->next cyclic buffer needs to be initialised. Otherwise I'd stick
with what you've posted.
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał "mina86" Nazarewicz (o o)
ooo +---[mina86@xxxxxxxxxx]---[mina86@jabber.org]---ooO--(_)--Ooo--
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
