ubuntu 11.10, systemtap and building my own kernel
(sort of a combo of ubuntu, systemtap and kernel question, hoping
it's not too far off-topic.)
for the purpose of an upcoming tutorial, i decided to install
systemtap on my fully-updated 64-bit ubuntu 11.10 laptop, then build a
new kernel and show how simple it is to use systemtap. it didn't turn
out well.
since i would be using a self-built kernel, i started here:
http://sourceware.org/systemtap/wiki/SystemTapWithSelfBuiltKernel
but i'm not convinced that page is entirely correct.
while i made sure all of the listed kernel options were selected, my
first concern is that i'm not sure why i should have to do make
headers_install. all that does is populate the in-tree usr/include/
directory with the exported header files. i'm not sure why that's
necessary. is it really required? does systemtap actually go looking
there for header files?
also, the rest of that page seems to explain how to make sure
systemtap can find your kernel build tree. but if you build and
install, then /lib/modules/release/build is a symlink to the build
tree, so i'm not sure anything else has to be done. the rest of that
page also seems unnecessary. thoughts?
in any event, i configured, built and installed my new kernel (based
on latest git pull from development kernel source), and rebooted to
get:
$ uname -r
3.4.0-rc2+
$
which is correct so, theoretically, i should be read to try a simple
systemtap example. reading here:
http://www.domaigne.com/blog/random/running-systemtap-on-ubuntu/
i tried:
$ stap -e 'probe kernel.function(sys_open) {log(hello world) exit()}'
and got:
= start =
In file included from /usr/share/systemtap/runtime/transport/transport.c:53:0,
from /usr/share/systemtap/runtime/print.c:18,
from /usr/share/systemtap/runtime/runtime.h:128,
from
/tmp/stapadEYdA/stap_59bddd394f89d5f186da7e250db36434_876.c:55:
/usr/share/systemtap/runtime/transport/relay_v2.c:242:2: error: initialization
from incompatible pointer type [-Werror]
/usr/share/systemtap/runtime/transport/relay_v2.c:242:2: error: (near
initialization for ‘__stp_relay_callbacks.create_buf_file’) [-Werror]
In file included from /usr/share/systemtap/runtime/print.c:18:0,
from /usr/share/systemtap/runtime/runtime.h:128,
from
/tmp/stapadEYdA/stap_59bddd394f89d5f186da7e250db36434_876.c:55:
/usr/share/systemtap/runtime/transport/transport.c: In function
‘_stp_get_root_dir’:
/usr/share/systemtap/runtime/transport/transport.c:380:8: error: ‘struct
hlist_head’ has no member named ‘next’
In file included from
/tmp/stapadEYdA/stap_59bddd394f89d5f186da7e250db36434_876.c:57:0:
/usr/share/systemtap/runtime/stat.c: In function ‘_stp_stat_get’:
/usr/share/systemtap/runtime/stat.c:213:2: error: ‘cpu_possible_map’ undeclared
(first use in this function)
/usr/share/systemtap/runtime/stat.c:213:2: note: each undeclared identifier is
reported only once for each function it appears in
/usr/share/systemtap/runtime/stat.c: In function ‘_stp_stat_clear’:
/usr/share/systemtap/runtime/stat.c:248:2: error: ‘cpu_possible_map’ undeclared
(first use in this function)
cc1: all warnings being treated as errors
make[1]: *** [/tmp/stapadEYdA/stap_59bddd394f89d5f186da7e250db36434_876.o]
Error 1
make: *** [_module_/tmp/stapadEYdA] Error 2
Pass 4: compilation failed. Try again with another '--vp 0001' option.
= end =
that doesn't look good. in particular, this error just looks
strange:
/usr/share/systemtap/runtime/transport/transport.c:380:8: error: ‘struct
hlist_head’ has no member named ‘next’
to make a long story short, that diagnostic is entirely correct --
struct hlist_head as it's defined in types.h is:
struct hlist_head {
struct hlist_node *first;
};
but that systemtap source file is trying to refer to a member called
next, which clearly does not exist.
am i doing something silly? can someone else with an ubuntu system
try this and let me know what happens? thanks.
rday
--
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
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TinyLinux project status
Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). Thanks a lot, Ezequiel. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: TinyLinux project status
Quoting Ezequiel García elezegar...@gmail.com: Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). Thanks a lot, Ezequiel. you might find what you're looking for at distrowatch.org d ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- It is told that such are the aerodynamics and wing loading of the bumblebee that, in principle, it cannot fly...if all this be true...life among bumblebees must bear a remarkable resemblance to life in the United States. -- John Kenneth Galbraith, in American Capitalism: The Concept of Countervailing Power ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: TinyLinux project status
Hi Ezequiel, 2012/4/10 Ezequiel García elezegar...@gmail.com: Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). I'm going to hazard a guess and say no. I remember working with the 2.4.x kernel and being able to get it to run on a board with 4 MB of RAM, and we were fairly tight. You have to keep in mind that your 1 Mb has to store your currently running user-mode programs as well. -- Dave Hylands Shuswap, BC, Canada http://www.davehylands.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
[Q] TinyLinux project status (resend)
Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. I'm adding Thomas to CC, cause he maintains (or used to according to elinux) a list of relevant patches. What's the status of this? Also, I would like to know what's the smallest kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). I now this might sound crazy, but perhaps with In-Place stuff and some hacks it could be possible. I've seen tests with 2 MB but not with 1 MB. Also, I've seen presentations by Matt Mackall [1] and Thomas Petazzoni [2]. but they're a few years old (ages in kernel time, right? :) Also, wich is the relevant mailing list? Not sure. Thanks a lot, Ezequiel. [1] http://ols.fedoraproject.org/OLS/Reprints-2004/Reprint-Mackall-OLS2004.pdf [2] http://www.celinux.org/elc08_presentations/linux-tiny.pdf ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: No subject
On Tue, Apr 10, 2012 at 10:48:14AM +0600, Martynov Semen wrote: one more time in plain text Yes, of course. It contains only one line: obj-$(CONFIG_MY_PROCLISTOUTPUT) += proclistoutput.o and works with Kconfig config MY_PROCLISTOUTPUT tristate Display a list of processes default y ---help--- This module prints a list of processes But I'm sure that the reason is not in my file, because: - If I put my code in a folder /drivers (and include my Makefile and Kconfig) then everything works perfectly (I can build kernel object and I can built-in my code to the kernel) - If I put my code in a folder /samples (and include my Makefile and Kconfig) then build-in the code I can't, but with .ko it works fine... I suppose that the reason in the kernel Makefile. The root Makefile contains this code (http://lxr.free-electrons.com/source/Makefile#L914) ifdef CONFIG_SAMPLES $(Q)$(MAKE) $(build)=samples endif where $(Q) = @ $(build) = -f scripts/Makefile.build obj and further I lose understanding of the events... 10.04.2012, 08:26, Vladimir Murzin murzi...@gmail.com: Hi Semen Could you share a Makefile for your module? Best wishes, Vladimir Murzin -Original Message- From: Martynov Semen semen-marty...@yandex.ru Sender: kernelnewbies-boun...@kernelnewbies.org Date: Mon, 09 Apr 2012 23:56:15 To: kernelnewbies@kernelnewbies.orgkernelnewbies@kernelnewbies.org Subject: No subject Good afternoon, I would like to understand, why I can't make the built-in object, when my code is in a folder /samples... I have my module-code and if I put it in a folder /samples, I can receive only loadable module (.ko) but if I want to receive the built-in object - it turns out nothing (.о-file is created, but my code doesn't get in a kernel). When I allocate my module-code in any other folder (for example, /drivers) it works normally - I can receive .ko and I can make the built-in object. Question - why I can't receive the built-in object when my code is in the folder /samples? What instruction in a make-file restricts it, and how? P.S.: Sorry for my english. -- Best regards, Semen A Martynov. Saint Petersburg, Russia. https://www.facebook.com/semen.martynov ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Я на Facebook: http://www.facebook.com/profile.php?id=1095131825 Hi Semen It happens because ./script isn't listed as a subdir for visiting and linking objects into vmlinux. Please, refer to [1] for details. [1] http://lxr.linux.no/linux+*/Makefile#L508 Best wishes, Vladimir Murzin ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: No subject
Yes, this is it! Thank you! 10.04.2012, 20:08, Vladimir Murzin murzi...@gmail.com: On Tue, Apr 10, 2012 at 10:48:14AM +0600, Martynov Semen wrote: one more time in plain text Yes, of course. It contains only one line: obj-$(CONFIG_MY_PROCLISTOUTPUT) += proclistoutput.o and works with Kconfig config MY_PROCLISTOUTPUT tristate Display a list of processes default y ---help--- This module prints a list of processes But I'm sure that the reason is not in my file, because: - If I put my code in a folder /drivers (and include my Makefile and Kconfig) then everything works perfectly (I can build kernel object and I can built-in my code to the kernel) - If I put my code in a folder /samples (and include my Makefile and Kconfig) then build-in the code I can't, but with .ko it works fine... I suppose that the reason in the kernel Makefile. The root Makefile contains this code (http://lxr.free-electrons.com/source/Makefile#L914) ifdef CONFIG_SAMPLES $(Q)$(MAKE) $(build)=samples endif where $(Q) = @ $(build) = -f scripts/Makefile.build obj and further I lose understanding of the events... 10.04.2012, 08:26, Vladimir Murzin murzi...@gmail.com: Hi Semen Could you share a Makefile for your module? Best wishes, Vladimir Murzin -Original Message- From: Martynov Semen semen-marty...@yandex.ru Sender: kernelnewbies-boun...@kernelnewbies.org Date: Mon, 09 Apr 2012 23:56:15 To: kernelnewbies@kernelnewbies.orgkernelnewbies@kernelnewbies.org Subject: No subject Good afternoon, I would like to understand, why I can't make the built-in object, when my code is in a folder /samples... I have my module-code and if I put it in a folder /samples, I can receive only loadable module (.ko) but if I want to receive the built-in object - it turns out nothing (.о-file is created, but my code doesn't get in a kernel). When I allocate my module-code in any other folder (for example, /drivers) it works normally - I can receive .ko and I can make the built-in object. Question - why I can't receive the built-in object when my code is in the folder /samples? What instruction in a make-file restricts it, and how? P.S.: Sorry for my english. -- Best regards, Semen A Martynov. Saint Petersburg, Russia. https://www.facebook.com/semen.martynov ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Я на Facebook: http://www.facebook.com/profile.php?id=1095131825 Hi Semen It happens because ./script isn't listed as a subdir for visiting and linking objects into vmlinux. Please, refer to [1] for details. [1] http://lxr.linux.no/linux+*/Makefile#L508 Best wishes, Vladimir Murzin -- Best regards, Semen A Martynov. Saint Petersburg, Russia. https://www.facebook.com/semen.martynov ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: ubuntu 11.10, systemtap and building my own kernel
On Tue, 10 Apr 2012, Frank Ch. Eigler wrote:
rpjday wrote:
[...]
$ stap -e 'probe kernel.function(sys_open) {log(hello world) exit()}'
and got:
= start =
[...]
cc1: all warnings being treated as errors
make[1]: *** [/tmp/stapadEYdA/stap_59bddd394f89d5f186da7e250db36434_876.o]
Error 1
make: *** [_module_/tmp/stapadEYdA] Error 2
Pass 4: compilation failed. Try again with another '--vp 0001' option.
Please try systemtap 1.7, or build one out of
git://sourceware.org/git/systemtap.git. Newer kernels sometimes
break systemtap assumptions; these are fixed pretty quickly in the
source tree, and get rolled into later releases.
Please report any further problems at system...@sourceware.org,
including /usr/bin/stap-report output, if able.
ok, but i'm curious ... i took a quick look at earlier kernels and i
don't see where struct hlist_head *ever* had a next member field
that is required by this version of systemtap (1.4).
can you clarify which kernel version(s) would have worked with this
version of systemtap? thanks.
rday
--
Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
Twitter: http://twitter.com/rpjday
LinkedIn: http://ca.linkedin.com/in/rpjday
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Re: ubuntu 11.10, systemtap and building my own kernel
Hi - On Tue, Apr 10, 2012 at 02:23:43PM -0400, Robert P. J. Day wrote: [...] ok, but i'm curious ... i took a quick look at earlier kernels and i don't see where struct hlist_head *ever* had a next member field that is required by this version of systemtap (1.4). I believe this was related to a viro's linux commit 9591718a5a. can you clarify which kernel version(s) would have worked with this version of systemtap? thanks. According to http://sourceware.org/ml/systemtap/2011-q1/msg00036.html, it was run with 2.6.9 ... 2.6.37. - FChE ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: ubuntu 11.10, systemtap and building my own kernel
Hi - On Tue, Apr 10, 2012 at 04:17:25PM -0400, Robert P. J. Day wrote: [...] just FYI, this is the current problem: [...] Yup, found it. For now, you could adjust your copy of the runtime.h header file s/map/mask/ and have at it. We'll plop presently a polished patch into proper place. - FChE ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
IRQs and memory consistency
This is a high level question about how IRQs work in the kernel. I have a struct that was kmalloc'd into ram. Within this struct there is an int, called devid. When I set this devid to a number that isn't 0, I print the following: checking devid value327683 in 0xcb6953d4 where 327683 is the value of the int and 0xcb6953d4 is the address of the struct that the devid value is in. Then an interrupt happens and when I print this value again at the beginning of the interrupt handler I get the following printed text: checking devid value0 in 0xcb6953d4 notice that the devid has been set to 0. I can't find any code on my end that would do this. Is there something, maybe related to memory address spaces in IRQ handlers that I don't know about? The IRQ and the setting of the devid value happen fairly close to each other in time. (like less than a second, or closer) Any ideas or guesses are appreciated. -Chris ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: ubuntu 11.10, systemtap and building my own kernel
On Tue, 10 Apr 2012, Frank Ch. Eigler wrote: Hi - On Tue, Apr 10, 2012 at 04:17:25PM -0400, Robert P. J. Day wrote: [...] just FYI, this is the current problem: [...] Yup, found it. For now, you could adjust your copy of the runtime.h header file s/map/mask/ and have at it. We'll plop presently a polished patch into proper place. actually, would it be possible to simplify the code? i see that systemtap's stat.c defines its own CPU iteration macro: #define stp_for_each_cpu(cpu) for_each_cpu_mask((cpu), cpu_possible_map) is there no way to directly use the kernel's linux/cpumask.h file, and something like for_each_possible_cpu? in any event, i git cloned systemtap so i can just pull the fix when it's committed. rday -- Robert P. J. Day Ottawa, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: IRQs and memory consistency
Sounds to me like there needs to be a flush of the processor cache by using memory barriers. I'm guessing that the IRQ is taken on a different thread and possibly a different processor and the value needs to be flushed. You might try having devid be an atomic_t and then use atomic_set and atomic_read so that the proper memory barriers are used. See: http://www.kernel.org/doc/Documentation/atomic_ops.txt -- Wink On Tue, Apr 10, 2012 at 1:22 PM, Christopher Harvey ch...@basementcode.comwrote: This is a high level question about how IRQs work in the kernel. I have a struct that was kmalloc'd into ram. Within this struct there is an int, called devid. When I set this devid to a number that isn't 0, I print the following: checking devid value327683 in 0xcb6953d4 where 327683 is the value of the int and 0xcb6953d4 is the address of the struct that the devid value is in. Then an interrupt happens and when I print this value again at the beginning of the interrupt handler I get the following printed text: checking devid value0 in 0xcb6953d4 notice that the devid has been set to 0. I can't find any code on my end that would do this. Is there something, maybe related to memory address spaces in IRQ handlers that I don't know about? The IRQ and the setting of the devid value happen fairly close to each other in time. (like less than a second, or closer) Any ideas or guesses are appreciated. -Chris ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: TinyLinux project status
minimum specs is available within the page: http://en.wikipedia.org/wiki/Tiny_Core_Linux http://en.wikipedia.org/wiki/Damn_Small_Linux 2012/4/10 Ezequiel García elezegar...@gmail.com Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). Thanks a lot, Ezequiel. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Regards, Peter Teoh ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: TinyLinux project status
http://www.chibios.org/dokuwiki/doku.php?id=chibios:documents:requirements This is 2KiB RAM for recommended configuration. It is not Linux, but is based on RTOS. 2012/4/11 Peter Teoh htmldevelo...@gmail.com minimum specs is available within the page: http://en.wikipedia.org/wiki/Tiny_Core_Linux http://en.wikipedia.org/wiki/Damn_Small_Linux 2012/4/10 Ezequiel García elezegar...@gmail.com Hello, I would like to know what is the current status of the tiny linux project? (The current goals, status and activeness). I've found this: http://elinux.org/Linux_Tiny but it seems a bit outdated. Also, I would like to know what's the smaller kernel (static and dynamic memory footprint) that can be achieved right now (without losing signicant funcionality). Is it possible to run linux a 1 MB SRAM board (no DRAM) ? (I am thinking at a ARM7 LPC2294 header board). Thanks a lot, Ezequiel. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Regards, Peter Teoh -- Regards, Peter Teoh ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: IRQs and memory consistency
Hi On Wed, Apr 11, 2012 at 03:22, Christopher Harvey ch...@basementcode.com wrote: The IRQ and the setting of the devid value happen fairly close to each other in time. (like less than a second, or closer) Hmmm, and how about the order? which one do you guess go first? setting value? or the IRQ handler? I had a sense that your code flow might (in reality) goes like this allocating struct RAM -- interrupted -- printing struct content -- back to initialize struct If that's true, then no wonder 0 (zero) is printed. I suggest to grab a spin lock if you really need atomicity during allocation and setting initial value, which in IRQ handler, you grab the lock before printing. Oh and since memory allocation could go slow, you might need to do allocation with GFP_ATOMIC. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
