Re: Which types of locking should I use?

[Tetsuo Handa <a5497108@xxxxxxxxxx>]

Hello, Jan.

I see. I will try to use linked list.
The 'const char *' data is a filename with caninicalized pathname,
and I don't want the array not to appear the same filename in
multiple indexes. So I will try something like this.

int len = strlen(filename) + 1;
const char *cp = kmalloc(len, GFP_KERNEL);
if (!cp) return;
memmove(cp, filename, len);
spin_lock();
// Scan linked list.
// Add cp to linked list if not found, kfree(cp) if found.
spin_unlock();

> 2) Be sure to remember how kmalloc works. It can only alocate power-of-2
>    sized buffers, 32 bytes minimum, PAGE_SIZE << 5 (or something like
I don't remember, but I thought kmalloc() with less than 32 bytes
doesn't return NULL. I called kmalloc() with 6 bytes
("const char *" + "unsigned short int") and (I thought) succeeded.
Max size I could allocate with kmalloc() is 128 * 1024 bytes,
which is equals to PAGE_SIZE << 5.
# I have no linux PC here to verify now.


Thank you.

--
     Tetsuo   (a5497108 _at_ anet.ne.jp)

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