Re: Memory Management

[Neil Horman <nhorman@redhat.com>]

On Sun, Jul 24, 2005 at 10:40:19PM -0300, Márcio Oliveira wrote:
> Neil Horman wrote:
> 
> >On Sat, Jul 23, 2005 at 08:16:20PM -0300, Márcio Oliveira wrote:
> > 
> >
> >>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.
> >>
> >>   
> >>
> >I honestly don't know.  I expect you haven't patched something correctly, 
> >have
> >you built the source tree with rpmbuild, or are you just extracting the 
> >tar file
> >from the rpm?
> >Neil
> >
> > 
> >
I honestly have no idea.  Suffice it to say, I never build out of the
kernel-source package.  Better to use the kernel src rpm, do an rpmbuild -bp on
the kernel src rpm, setting your target arch accordingly.  I have no problems
with that on any RHEL kernels.
Neil

>     I'm using the kernel-source package and trying to compiling the 
> source (in /usr/src/linux-2.4 directory) with "make config", "make dep", 
> "make clean", "make bzImage", "make modules" and "make 
> modules_install".  I also try to compile a RHEL3 kernel-source without 
> the sysrq-m changes on other RHEL3 systems and get the same errors...
> 
>    If I try to compile a kernel source provide by kernel.org, I don't 
> get the errors above, and the kernel compile works. When I try to 
> compile the RHEL3 kernel-source, the "make config", "make dep", "make 
> clean" and "make bzImage" commands works fine but when I run "make 
> modules" command I get the errors above. I think that is some issue with 
> the RHEL3 kernel-source package because other kernel sources (not Red 
> Hat kernel) compile without problems.
> 
>   I will try to compile the kernel using rpmbuild and check the 
> results, plus the slabinfo informations.
> 
> Thanks again,
> 
> Márcio.

-- 
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 *Neil Horman
 *Software Engineer
 *Red Hat, Inc.
 *nhorman@redhat.com
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