fixing weird termio issues that complicate debugging

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

2) it calls wr_scrn_setw and tinkers with the windows size very early in the init which can make your terminal weird

3) it calls rte_eal_init which produces a lot of nice debug output, which is fine

4) it calls pktgen_init_screen, which calls wr_scrn_init, which calls wr_scrn_erase which destroys the valuable debug output just created in
(c) which is a bad thing

5) it calls wr_print_copyright and dumps more boilerplate I am not sure is needed

6) it logs some helpful messages about the port / descriptor settings which is fine

7) it calls the pktgen_config_ports function which can crash in ways you need the destroyed debug output to fix.

For example in my case that function crashes here:

         if (pktgen.nb_ports == 0)
                 pktgen_log_panic("*** Did not find any ports to use ***");

8) Later it makes a logo and a splash screen (wr_log, wr_splash_screen). Is this stuff really needed? This is a ton of output for just starting up some test program.

To fix this debug problem I propose some changes which I am happy to help develop:

1) decide what of this output we really need here and greatly simplify how much gets printed out

2) move wr_scrn_setw right before pktgen_init_screen and after rte_eal_init to prevent damaging that output

3) consider how wr_scrn_init is called in pktgen_init_screen, because it calls wr_scrn_erase which damages output

4) I think that pktgen_config_ports should be called before all this weird screen init stuff, so that if it fails you can actually see what happened there.

One other random topic... on the long lines of code it looks like there are some gigantic tab-indents pushing things off to the right still. One example, maybe there are others or another setting which is needed to fix all of these:

                 info->seq_pkt = (pkt_seq_t *)rte_zmalloc_socket(buff,

(sizeof(pkt_seq_t) * NUM_TOTAL_PKTS),

RTE_CACHE_LINE_SIZE,
rte_socket_id());

Thoughts?

Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

2) it calls wr_scrn_setw and tinkers with the windows size very early in the init which can make your terminal weird

3) it calls rte_eal_init which produces a lot of nice debug output, which is fine

4) it calls pktgen_init_screen, which calls wr_scrn_init, which calls wr_scrn_erase which destroys the valuable debug output just created in
(c) which is a bad thing

5) it calls wr_print_copyright and dumps more boilerplate I am not sure is needed

6) it logs some helpful messages about the port / descriptor settings which is fine

7) it calls the pktgen_config_ports function which can crash in ways you need the destroyed debug output to fix.

For example in my case that function crashes here:

        if (pktgen.nb_ports == 0)
                pktgen_log_panic("*** Did not find any ports to use ***");

8) Later it makes a logo and a splash screen (wr_log, wr_splash_screen). Is this stuff really needed? This is a ton of output for just starting up some test program.

To fix this debug problem I propose some changes which I am happy to help develop:

1) decide what of this output we really need here and greatly simplify how much gets printed out

2) move wr_scrn_setw right before pktgen_init_screen and after rte_eal_init to prevent damaging that output

3) consider how wr_scrn_init is called in pktgen_init_screen, because it calls wr_scrn_erase which damages output

4) I think that pktgen_config_ports should be called before all this weird screen init stuff, so that if it fails you can actually see what happened there.

One other random topic... on the long lines of code it looks like there are some gigantic tab-indents pushing things off to the right still. One example, maybe there are others or another setting which is needed to fix all of these:

                info->seq_pkt = (pkt_seq_t *)rte_zmalloc_socket(buff, 

(sizeof(pkt_seq_t) * NUM_TOTAL_PKTS),

RTE_CACHE_LINE_SIZE,
rte_socket_id());

Thoughts?
Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

2) it calls wr_scrn_setw and tinkers with the windows size very early in the init which can make your terminal weird

3) it calls rte_eal_init which produces a lot of nice debug output, which is fine

4) it calls pktgen_init_screen, which calls wr_scrn_init, which calls wr_scrn_erase which destroys the valuable debug output just created in
(c) which is a bad thing

5) it calls wr_print_copyright and dumps more boilerplate I am not sure is needed

6) it logs some helpful messages about the port / descriptor settings which is fine

7) it calls the pktgen_config_ports function which can crash in ways you need the destroyed debug output to fix.

For example in my case that function crashes here:

        if (pktgen.nb_ports == 0)
                pktgen_log_panic("*** Did not find any ports to use ***");

8) Later it makes a logo and a splash screen (wr_log, wr_splash_screen). Is this stuff really needed? This is a ton of output for just starting up some test program.

To fix this debug problem I propose some changes which I am happy to help develop:

1) decide what of this output we really need here and greatly simplify how much gets printed out

2) move wr_scrn_setw right before pktgen_init_screen and after rte_eal_init to prevent damaging that output

3) consider how wr_scrn_init is called in pktgen_init_screen, because it calls wr_scrn_erase which damages output

4) I think that pktgen_config_ports should be called before all this weird screen init stuff, so that if it fails you can actually see what happened there.

One other random topic... on the long lines of code it looks like there are some gigantic tab-indents pushing things off to the right still. One example, maybe there are others or another setting which is needed to fix all of these:

                info->seq_pkt = (pkt_seq_t *)rte_zmalloc_socket(buff, 

(sizeof(pkt_seq_t) * NUM_TOTAL_PKTS),

RTE_CACHE_LINE_SIZE,
rte_socket_id());

Thoughts?
Matthew Hall

Quoted 1 line · dev on behalf of Matthew Hall

Hello,

Quoted 16 lines

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

Quoted 7 lines

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement. As you may know I do a lot of debugging on Pktgen and I feel they are a nuisance. I can try to see if we can clean up these messages, but do not hold your breath on getting them to be removed.

Quoted 6 lines

2) it calls wr_scrn_setw and tinkers with the windows size very early in the init which can make your terminal weird

3) it calls rte_eal_init which produces a lot of nice debug output, which is fine

IMO most of the information from DPDK is not very useful as why do I need to see every lcore line, plus a lot of more useless information. Most of the information could be reduced a couple of lines or only report issues not just a bunch of useless information.

Quoted 4 lines

4) it calls pktgen_init_screen, which calls wr_scrn_init, which calls wr_scrn_erase which destroys the valuable debug output just created in
(c) which is a bad thing

The screen init should be scrolling the information off the screen to preserve that info, unless it was changed by mistake.

Quoted 22 lines

5) it calls wr_print_copyright and dumps more boilerplate I am not sure is needed

6) it logs some helpful messages about the port / descriptor settings which is fine

7) it calls the pktgen_config_ports function which can crash in ways you need the destroyed debug output to fix.

For example in my case that function crashes here:

        if (pktgen.nb_ports == 0)
                pktgen_log_panic("*** Did not find any ports to use ***");

8) Later it makes a logo and a splash screen (wr_log, wr_splash_screen). Is this stuff really needed? This is a ton of output for just starting up some test program.

To fix this debug problem I propose some changes which I am happy to help develop:

Quoted 8 lines

1) decide what of this output we really need here and greatly simplify how much gets printed out

2) move wr_scrn_setw right before pktgen_init_screen and after rte_eal_init to prevent damaging that output

3) consider how wr_scrn_init is called in pktgen_init_screen, because it calls wr_scrn_erase which damages output

Again it could be scrolling that information off the screen, just need a large screen scroll buffer.

Quoted 9 lines

4) I think that pktgen_config_ports should be called before all this weird screen init stuff, so that if it fails you can actually see what happened there.

One other random topic... on the long lines of code it looks like there are some gigantic tab-indents pushing things off to the right still. One example, maybe there are others or another setting which is needed to fix all of these:

Please use tab stop of 4 instead of 8. IMO tab stop of 8 is so 1970’s and we should not need tab stop of 8 as any system today will work. :-)

Quoted 9 lines

                info->seq_pkt = (pkt_seq_t *)rte_zmalloc_socket(buff, 

(sizeof(pkt_seq_t) * NUM_TOTAL_PKTS),

RTE_CACHE_LINE_SIZE,
rte_socket_id());

Thoughts?
Matthew Hall

Improvement to Pktgen is always welcome and the copyright info is going to be a bit hard to remove as that was one of the requirements when I open sourced the code. I understand it maybe a bit of output. I do not think it is really a user issue causing users to stop using it as startup is only down once, in my case I may start Pktgen a few times a day for development and it does not seem to slow me down much. :-)

Quoted 1 line

Regards,
Keith

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement. As you may know I do a lot of debugging on Pktgen and I feel they are a nuisance. I can try to see if we can clean up these messages, but do not hold your breath on getting them to be removed.

IMO most of the information from DPDK is not very useful as why do I need to see every lcore line, plus a lot of more useless information. Most of the information could be reduced a couple of lines or only report issues not just a bunch of useless information.

The screen init should be scrolling the information off the screen to preserve that info, unless it was changed by mistake.

Please use tab stop of 4 instead of 8. IMO tab stop of 8 is so 1970’s and we should not need tab stop of 8 as any system today will work. :-)

Quoted 21 lines · dev on behalf of Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

Quoted 3 lines

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement.

As you may know I do a lot of debugging on Pktgen and I feel they are a nuisance. I can try to see if we can clean up these messages, but do not hold your breath on getting them to be removed.

Quoted 27 lines · Keith

Quoted 24 lines · dev on behalf of Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

Quoted 2 lines

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement.

In that case, why is it under a BSD'ish license instead of something like GPL that's designed to prevent it in the first place? Might be too late to change it by now, just wondering.

Quoted 4 lines

As you may know I do a lot of debugging on Pktgen and I feel they are a nuisance. I can try to see if we can clean up these messages, but do not hold your breath on getting them to be removed.

It would make a world of difference if it just printed the copyright etc in a couple of lines during startup, instead of taking over the entire screen for several seconds.

This is a whole lot like those anti-piracy ad campaigns on DVDs which you cant skip, so all the *legitimate* users are forced to suffer through them but all the bad guys just rip it out of their copies. DRM that ends up hurting the legitimate users the most is never a good idea.

- Panu -

Quoted 28 lines · Panu Matilainen

Quoted 27 lines · Keith

Quoted 24 lines · dev on behalf of Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

Quoted 6 lines

Quoted 2 lines

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement.

In that case, why is it under a BSD'ish license instead of something like GPL that's designed to prevent it in the first place? Might be too late to change it by now, just wondering.

DPDK is BSD, so you can not use a GPL application with DPDK (I think) anyway I can try to speed you the screens, but does it really matter as these are only at startup and I normally leave pktgen running for long periods of time. The extra time at the start does not seem to be a big issue, right?

Quoted 14 lines

Quoted 4 lines

As you may know I do a lot of debugging on Pktgen and I feel they are a nuisance. I can try to see if we can clean up these messages, but do not hold your breath on getting them to be removed.

It would make a world of difference if it just printed the copyright etc in a couple of lines during startup, instead of taking over the entire screen for several seconds.

This is a whole lot like those anti-piracy ad campaigns on DVDs which you cant skip, so all the *legitimate* users are forced to suffer through them but all the bad guys just rip it out of their copies. DRM that ends up hurting the legitimate users the most is never a good idea.

Quoted 4 lines

- Panu -

Regards,
Keith

I would rip out the whole tty control and theming nonsense and then just print one line copyright on startup.

Quoted 28 lines · Panu Matilainen

Quoted 27 lines · Keith

Quoted 24 lines · dev on behalf of Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

Quoted 6 lines

Quoted 2 lines

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement.

In that case, why is it under a BSD'ish license instead of something like GPL that's designed to prevent it in the first place? Might be too late to change it by now, just wondering.

DPDK is BSD, so you can not use a GPL application with DPDK (I think)

anyway I can try to speed you the screens, but does it really matter as these are only at startup and I normally leave pktgen running for long periods of time. The extra time at the start does not seem to be a big issue, right?

Quoted 30 lines · Keith

Quoted 28 lines · Panu Matilainen

Quoted 27 lines · Keith

Quoted 24 lines · dev on behalf of Matthew Hall

Hello,

Since the pktgen code is reindented I am finding time to read through it and experiment and see if I can get it working.

I have issues with the init process of pktgen. It is difficult to debug it because the init code does a lot of very scary stuff to the terminal control / TTY device at inconvenient times in an inconvenient order, and in the process damages the debug output and damages the screen of your GDB without doing weird things to run GDB on a different TTY.

Of course I am willing to contribute patches and not just complain, but first I need some help to follow what is going on.

Here is the problematic call-flow with some explanation what went wrong trying it on some community machines outside of its original environment:

1) it calls printf("\n%s %s\n", wr_copyright_msg(), wr_powered_by()); which dumps tons of weird boilerplate of licenses, copyrights, code creator, etc.

It is open source and everybody that matters already knows who coded it, so is this stuff really that important? This gets in the way when you are trying to work on it and I just have to comment it out.

Quoted 8 lines

Quoted 6 lines

Quoted 2 lines

One problem is a number of people wanted to steal the code and use in a paid application, so the copyright is some what a requirement.

In that case, why is it under a BSD'ish license instead of something like GPL that's designed to prevent it in the first place? Might be too late to change it by now, just wondering.

DPDK is BSD, so you can not use a GPL application with DPDK (I think)

Well I sure hope the license is not chosen by that assumption. Why assume when you can trivially check, eg:
http://www.gnu.org/licenses/license-list.html

DPDK itself is under the very lax 3-clause BSD license which is compatible with the GPL. The 4-clause "advertising license" used by pktgen is not. But its not the license I'm complaining about.

Quoted 4 lines

anyway I can try to speed you the screens, but does it really matter as these are only at startup and I normally leave pktgen running for long periods of time. The extra time at the start does not seem to be a big issue, right?

We wouldn't be discussing this if it was not an issue. It is offensive enough to turn away both users and contributors, and merely speeding up a bit is not going to make it a whole lot better.

As I (and now others as well) already suggested changing it to a one line printout is what would make worlds of difference while still complying with the license AFAICT. The license text requires printing out the copyright notice, it does not say anything about rendering it in full-screen ascii-art, or printing out the entire license.

- Panu -

Quoted 4 lines · Panu Matilainen

We wouldn't be discussing this if it was not an issue. It is offensive enough to turn away both users and contributors, and merely speeding up a bit is not going to make it a whole lot better.

Quoted 5 lines

As I (and now others as well) already suggested changing it to a one line printout is what would make worlds of difference while still complying with the license AFAICT. The license text requires printing out the copyright notice, it does not say anything about rendering it in full-screen ascii-art, or printing out the entire license.

Thank you Panu for your input, I will think about.