kernel 2.4.17

[Arne Gehlhaar <gehlhaar@xxxxxxx>]

Hello,

I think I have successfully applied the kaio patch to the 2.4.17 kernel. 
However there were a few problems that I would like somebody with 
profound kernel and/or kaio knowledge to comment on...

Two files failed to patch due to changes in the originals. These were 
easily applied manually, though:

> patching file ./arch/i386/kernel/entry.S
> Hunk #1 FAILED at 646.
> 1 out of 1 hunk FAILED -- saving rejects to file ./arch/i386/kernel/entry.S.rej

> patching file ./include/linux/sched.h
> Hunk #1 FAILED at 395.
> 1 out of 1 hunk FAILED -- saving rejects to file ./include/linux/sched.h.rej


the real problems started with the ./mm/filemap.c The patch applied 
successfully, however I got a couple of compile errors when building the 
new kernel. The problems were a missing parameter in page_cache_alloc() 
and undeclared function page_cache_free(). Without any knowledge in 
kernel hacking and kaio issues, all I had was my common sense. Please 
have a look at the following patch and tell me if the changes I made to 
the filemap.c (after I applied the kaio patch) make any sense.

--- filemap.c   Fri Mar  8 08:51:53 2002
+++ /usr/src/linux/mm/filemap.c Wed Mar  6 17:16:51 2002
@@ -2537,7 +2537,7 @@
                 */
                if (!page_cache) {
                        spin_unlock(&pagecache_lock);
-                       page_cache = page_cache_alloc();
+                       page_cache = page_cache_alloc(mapping);
                        /*
                         * That could have slept, so go around to the
                         * very beginning..
@@ -2572,13 +2572,13 @@
        if (ret) { /* recheck return from kaio_enqueue */
                for (i--; i >=0; i--) {
                        assert(kaiocb->kaio_pages[i]);
-                       page_cache_free(kaiocb->kaio_pages[i]);
+                       page_cache_release(kaiocb->kaio_pages[i]);
                }
                if (kaiocb->kaio_pages != &kaiocb->kaio_page_inline)
                        kfree(kaiocb->kaio_pages);
        }
        if (page_cache)
-               page_cache_free(page_cache);
+               page_cache_release(page_cache);
        UPDATE_ATIME(inode);
        return ret;
 }


As far as I can tell, the kernel is stable and the async i/o seems to be 
working. FYI: I run Sybase 11.0.3.3-6 with async i/o enabled on raw 
devices.


Any comments appreciated!

Arne

--
Institute of Shipping Economics and Logistics    http://www.isl.org/
Arne Gehlhaar                                mailto:gehlhaar@xxxxxxx
Universitaetsallee GW1 Block A                phone:+49.421.22096.49
D-28359 Bremen, Germany                         fax:+49.421.22096.55