Re: Memory Management

["Márcio Oliveira" <moliveira@latinsourcetech.com>]

Neil,

>The best way I can think to do that is take a look at /proc/slabinfo.  That will
>likely give you a pointer to which area of code is eating up your memory.
>  
>
OK. I will monitor the /proc/slabinfo file.

>Based on the sysrq-m info you posted it looks like due to fragmentation the
>largest chunk of memory you can allocate is 2MB (perhaps less depending on
>address space availability).  If you can build a test kernel to do a show_state
>rather than a show_mem at the beginning of oom_kil, then you should be able to
>tell who is trying to do an allocation that leads to kswapd calling
>out_of_memory.
>  
>
Neil, I'm trying to recompile the kernel source 2.4.21-32.0.1 and get 
some error messages:

In file included from 
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/prefetch.h:13,
                 from 
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/list.h:6,
                 from 
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:12,
                 from 3w-xxxx.c:172:
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:61: warning: 
parameter names (without types) in function declaration
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:61: field 
`loops_per_jiffy_R_ver_str' declared as a function
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:84: invalid 
suffix on integer constant
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:84: syntax error 
before numeric constant
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:84: warning: 
function declaration isn't a prototype
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:269: invalid 
suffix on integer constant
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:269: syntax 
error before numeric constant
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:269: warning: 
function declaration isn't a prototype
/usr/src/linux-2.4.21-32.0.1.EL/include/asm/processor.h:273: warning: 
parameter names (without types) in function declaration
In file included from 3w-xxxx.c:172:
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:190: invalid 
suffix on integer constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:190: syntax error 
before numeric constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:190: 
`inter_module_register_R_ver_str' declared as function returning a function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:190: warning: 
function declaration isn't a prototype
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:191: invalid 
suffix on integer constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:191: syntax error 
before numeric constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:191: 
`inter_module_unregister_R_ver_str' declared as function returning a 
function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:191: warning: 
function declaration isn't a prototype
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:192: 
`inter_module_get_R_ver_str' declared as function returning a function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:192: warning: 
parameter names (without types) in function declaration
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:193: 
`inter_module_get_request_R_ver_str' declared as function returning a 
function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:193: warning: 
parameter names (without types) in function declaration
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:194: invalid 
suffix on integer constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:194: syntax error 
before numeric constant
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:194: 
`inter_module_put_R_ver_str' declared as function returning a function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:194: warning: 
function declaration isn't a prototype
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:203: 
`try_inc_mod_count_R_ver_str' declared as function returning a function
/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h:203: warning: 
parameter names (without types) in function declaration
make[3]: *** [3w-xxxx_10200033.o] Error 1
make[3]: Leaving directory 
`/usr/src/linux-2.4.21-32.0.1.EL/drivers/addon/3w-xxxx_10200033'
make[2]: *** [_modsubdir_3w-xxxx_10200033] Error 2
make[2]: Leaving directory `/usr/src/linux-2.4.21-32.0.1.EL/drivers/addon'
make[1]: *** [_modsubdir_addon] Error 2
make[1]: Leaving directory `/usr/src/linux-2.4.21-32.0.1.EL/drivers'
make: *** [_mod_drivers] Error 2

Is there any relationship between the sysrq-m changes to do show_state() 
rather than a show_mem() and the compiling erros?

/usr/src/linux-2.4.21-32.0.1.EL/include/linux/prefetch.h, line 13:
    #include <asm/processor.h>

/usr/src/linux-2.4.21-32.0.1.EL/include/linux/list.h ,line 6:
    #include <linux/prefetch.h>

/usr/src/linux-2.4.21-32.0.1.EL/include/linux/module.h, line 12:
    #include <linux/list.h>

3w-xxxx.c, line 172:
    #include <linux/module.h>

Any ideia about the kernel compiling erros?

(If I try to recompile a kernel.org kernel, it is compiled fine).

Thanks again.

Márcio.