Re: OOPS in do_try_to_free_pages with VERY large software RAID array

["Randy.Dunlap" <rddunlap@osdl.org>]

On Tue, 11 Mar 2003 12:38:44 -0500 "Rechenberg, Andrew" <ARechenberg@shermanfinancialgroup.com> wrote:

| Kevin,
| 
| I tried patching md by hand since you're patch is for 2.5 but I'm having
| some issues.  When I try to make bzImage I'm getting the following
| error:
| 
| md.c:139: `single_release' undeclared here (not in a function)
| md.c:139: initializer element is not constant
| md.c:139: (near initialization for `md_state_fops.release')
| md.c:140: initializer element is not constant
| md.c:140: (near initialization for `md_state_fops')
| md.c: In function `md_state_seq_show':
| md.c:3219: warning: passing arg 1 of pointer to function from
| incompatible pointer type
| md.c: In function `md_state_open_fs':
| md.c:3238: warning: implicit declaration of function `single_open'
| make[3]: *** [md.o] Error 1
| make[3]: Leaving directory `/usr/src/linux-flux/drivers/md'
| make[2]: *** [first_rule] Error 2
| make[2]: Leaving directory `/usr/src/linux-flux/drivers/md'
| make[1]: *** [_subdir_md] Error 2
| make[1]: Leaving directory `/usr/src/linux-flux/drivers'
| make: *** [_dir_drivers] Error 2
| 
| Can you tell me if the single_release is a 2.5 "thing?"  Can you point
| me in the right direction as to how to fix this problem?.
| 
| Thanks,
| Andy.
| 
| -----Original Message-----
| From: Kevin P. Fleming [mailto:kpfleming@cox.net] 
| Sent: Monday, March 10, 2003 2:48 PM
| To: Martin J. Bligh
| Cc: Rechenberg, Andrew; linux-kernel@vger.kernel.org
| Subject: Re: OOPS in do_try_to_free_pages with VERY large software RAID
| array
| 
| 
| Martin J. Bligh wrote:
| > At a wild guess (OK, I only looked for about 1 minute), 
| > md_status_read_proc is generating more than 4K of information, and 
| > overwriting the end of it's 4K page. Throw some debug in there, and 
| > get it to printk how much of the buffer it thinks it's using (just 
| > printk sz every time it changes it). If it's > 4K, convert it to the 
| > seq_file interface.
| > 
| > May not be it, but it seems likely given the unusual scale of what 
| > you're doing, and it's easy to check.
| > 
| > M.
| 
| I posted a patch to do exactly this last week to the Linux-RAID mailing
| list. If 
| you check the archives you should find it. This problem also occurs if
| you use 
| the device-mapper under 2.5.X, because it makes all 256 md minors appear
| in the 
| tables and /proc/mdstat wants to tell you about all of them.

seq_file interfaces are in 2.4.recent (since around 2.4.15), but
not the single_* methods, only the iterative methods.

--
~Randy