Re: [PATCH] reduce stack in cpqarray.c::ida_ioctl()

Randy.Dunlap (rddunlap@osdl.org)
Thu, 3 Apr 2003 13:21:37 +0000


On Thu, 3 Apr 2003 14:18:57 -0600 "Cameron, Steve" <Steve.Cameron@hp.com> wrote:

|
| > This patch to 2.5.66 reduces stack usage in ida_ioctl() by about
| > 0x500 bytes (on x86).
|
| Looks ok to me, (but i haven't tried it.)

Me either (-ENOHARDWARE).

| > There is a possibility that the allocation here should be done one time
| > only and the buffer pointer saved for re-use instead of allocating it
| > on each call to ida_ioctl. If that's desirable, I'll have a few
| > questions.
|
| No, I don't think so. I think we should
| allow for the possibllity of concurrent calls
| to this ioctl. (whether linux allows it is
| another question. I think it used to be the case
| that only one ioctl could get in at a time... I can't
| recall if it's still that way.)

Well, my questions were along those lines, like:
. allocate a buffer per hba or per disk?
. how much is ida_ioctl() [passthru] used?
. it's not on a normal(!?!) read path, is it?
if so, using kmalloc() that could fail would be a bad idea.

--
~Randy
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