On 04/09/2015 10:00 PM, nick wrote:
On 2015-04-09 09:51 PM, Ruben Safir wrote:
It is passover so I've read over much of this text, but I have to say that in general, I'm way ahead of this book. Although I have limited knowledge of Kernel technology in the specific, the C code, data structs, and programming concepts are spoon feed in this text and its wasting too much time with words that are more easily explained with coding examples and UML charts. I don't need a chapter explaining how to use ps and the basis of Unix architecture. This text is targeted to a different audience, and FWIW, I'm not certain it does a good job of that either. The guys who write these texts fall in love with their own voices. I know, I've suffered this disease myself when I've written tech articles and books.
I can''t recommend this book to anyone. Anyone who doesn't understand the basics of I/O processer blocks is not going to understand
static void update_curr(struct cfs_rq *cfs_rq)
and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well enough for coders unfamiliar with the kernel data structs of which BTW struct cfs_rq is not one defined in the text.
:(
I'm looking for something more like this, but flushed out more as a textbook
http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index...., and some mentoring, I hope.
Ruben
Ruben, The book is for an intro to the kernel not a complete walk through of each subsystem. If that is the case,why not read the subsystem code and docs in the kernel. I am a novice myself in terms of patch and coding experience but will be glad to explain the code as I have read lots of it.
Thank you nick. Yes, I downloaded the entire source from Kernel.org and it is sitting on both my laptop and in virtual machines where I have already compiled some stuff and not broken my VMs yets :) I'm looking over /home/ruben/linux-3.19.3/Documentation/scheduler [ruben@stat13 scheduler]$ ls 00-INDEX sched-deadline.txt sched-rt-group.txt media=legal -o sides=two-sided-long-edg sched-design-CFS.txt sched-stats.txt sched-arch.txt sched-domains.txt sched-bwc.txt sched-nice-design.txt I also see in the code there is significant documentation. Right now I am trying to figure out what is the relationship between struct sched_entity and struct cfs_rq and struct rq_of why do we have both?? there is a cast in update_curr u64 now = rq_of(cfs_rq)->clock; or is rq_of a function that returns a pointer is a struct that I missed?
Nick
On 03/22/2015 08:35 PM, nick wrote:
On 2015-03-22 08:05 PM, Ruben Safir wrote:
On 03/22/2015 07:30 PM, nick wrote:
I would recommend reading Chapters 3 and 4 of Linux Kernel Development by Robert Love as when I was learning the scheduler and process management
how much has the scheduler changed since then. It was completely overhauled when the CFS was created
The 3rd edition of this book was written after CFS was in the kernel so the chapters are pretty up to date. Nick
_______________________________________________ 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
.
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On 2015-04-09 10:12 PM, Ruben Safir wrote:
On 04/09/2015 10:00 PM, nick wrote:
On 2015-04-09 09:51 PM, Ruben Safir wrote:
It is passover so I've read over much of this text, but I have to say that in general, I'm way ahead of this book. Although I have limited knowledge of Kernel technology in the specific, the C code, data structs, and programming concepts are spoon feed in this text and its wasting too much time with words that are more easily explained with coding examples and UML charts. I don't need a chapter explaining how to use ps and the basis of Unix architecture. This text is targeted to a different audience, and FWIW, I'm not certain it does a good job of that either. The guys who write these texts fall in love with their own voices. I know, I've suffered this disease myself when I've written tech articles and books.
I can''t recommend this book to anyone. Anyone who doesn't understand the basics of I/O processer blocks is not going to understand
static void update_curr(struct cfs_rq *cfs_rq)
and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well enough for coders unfamiliar with the kernel data structs of which BTW struct cfs_rq is not one defined in the text.
:(
I'm looking for something more like this, but flushed out more as a textbook
http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index...., and some mentoring, I hope.
Ruben
Ruben, The book is for an intro to the kernel not a complete walk through of each subsystem. If that is the case,why not read the subsystem code and docs in the kernel. I am a novice myself in terms of patch and coding experience but will be glad to explain the code as I have read lots of it.
Thank you nick. Yes, I downloaded the entire source from Kernel.org and it is sitting on both my laptop and in virtual machines where I have already compiled some stuff and not broken my VMs yets :)
I'm looking over /home/ruben/linux-3.19.3/Documentation/scheduler [ruben@stat13 scheduler]$ ls
00-INDEX sched-deadline.txt sched-rt-group.txt media=legal -o sides=two-sided-long-edg sched-design-CFS.txt sched-stats.txt sched-arch.txt sched-domains.txt sched-bwc.txt sched-nice-design.txt
I also see in the code there is significant documentation.
Right now I am trying to figure out what is the relationship between struct sched_entity and struct cfs_rq and struct rq_of
why do we have both??
The way that these structures are related is sched_enity is the entity for the task's scheduling information or the task_struct of the a excuting process to be exact. Furthermore cfs_rq is the runquenue on which the task is running or selected to run on by schedule,the main scheduling function of the kernel. Finally here is the function definition for rq_of to answer your question, static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } Before asking questions again like this please look into either using lxr or ctags to navigate the kernel tree for answers as can be faster then waiting for me or someone else to respond. Thanks, Nick
there is a cast in update_curr u64 now = rq_of(cfs_rq)->clock;
or is rq_of a function that returns a pointer is a struct that I missed?
Nick
On 03/22/2015 08:35 PM, nick wrote:
On 2015-03-22 08:05 PM, Ruben Safir wrote:
On 03/22/2015 07:30 PM, nick wrote:
I would recommend reading Chapters 3 and 4 of Linux Kernel Development by Robert Love as when I was learning the scheduler and process management
how much has the scheduler changed since then. It was completely overhauled when the CFS was created
The 3rd edition of this book was written after CFS was in the kernel so the chapters are pretty up to date. Nick
_______________________________________________ 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
.
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On 04/09/2015 10:52 PM, nick wrote:
Before asking questions again like this please look into either using lxr or ctags to navigate the kernel tree for answers as can be faster then waiting for me or someone else to respond.
well, I reading the text is ctags aren't much value there.
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website. How do you search these things out? Ruben On Thu, Apr 09, 2015 at 10:52:03PM -0400, nick wrote:
On 2015-04-09 10:12 PM, Ruben Safir wrote:
On 04/09/2015 10:00 PM, nick wrote:
On 2015-04-09 09:51 PM, Ruben Safir wrote:
It is passover so I've read over much of this text, but I have to say that in general, I'm way ahead of this book. Although I have limited knowledge of Kernel technology in the specific, the C code, data structs, and programming concepts are spoon feed in this text and its wasting too much time with words that are more easily explained with coding examples and UML charts. I don't need a chapter explaining how to use ps and the basis of Unix architecture. This text is targeted to a different audience, and FWIW, I'm not certain it does a good job of that either. The guys who write these texts fall in love with their own voices. I know, I've suffered this disease myself when I've written tech articles and books.
I can''t recommend this book to anyone. Anyone who doesn't understand the basics of I/O processer blocks is not going to understand
static void update_curr(struct cfs_rq *cfs_rq)
and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well enough for coders unfamiliar with the kernel data structs of which BTW struct cfs_rq is not one defined in the text.
:(
I'm looking for something more like this, but flushed out more as a textbook
http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index...., and some mentoring, I hope.
Ruben
Ruben, The book is for an intro to the kernel not a complete walk through of each subsystem. If that is the case,why not read the subsystem code and docs in the kernel. I am a novice myself in terms of patch and coding experience but will be glad to explain the code as I have read lots of it.
Thank you nick. Yes, I downloaded the entire source from Kernel.org and it is sitting on both my laptop and in virtual machines where I have already compiled some stuff and not broken my VMs yets :)
I'm looking over /home/ruben/linux-3.19.3/Documentation/scheduler [ruben@stat13 scheduler]$ ls
00-INDEX sched-deadline.txt sched-rt-group.txt media=legal -o sides=two-sided-long-edg sched-design-CFS.txt sched-stats.txt sched-arch.txt sched-domains.txt sched-bwc.txt sched-nice-design.txt
I also see in the code there is significant documentation.
Right now I am trying to figure out what is the relationship between struct sched_entity and struct cfs_rq and struct rq_of
why do we have both??
The way that these structures are related is sched_enity is the entity for the task's scheduling information or the task_struct of the a excuting process to be exact. Furthermore cfs_rq is the runquenue on which the task is running or selected to run on by schedule,the main scheduling function of the kernel. Finally here is the function definition for rq_of to answer your question, static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } Before asking questions again like this please look into either using lxr or ctags to navigate the kernel tree for answers as can be faster then waiting for me or someone else to respond. Thanks, Nick
there is a cast in update_curr u64 now = rq_of(cfs_rq)->clock;
or is rq_of a function that returns a pointer is a struct that I missed?
Nick
On 03/22/2015 08:35 PM, nick wrote:
On 2015-03-22 08:05 PM, Ruben Safir wrote:
On 03/22/2015 07:30 PM, nick wrote:
I would recommend reading Chapters 3 and 4 of Linux Kernel Development by Robert Love as when I was learning the scheduler and process management
how much has the scheduler changed since then. It was completely overhauled when the CFS was created
The 3rd edition of this book was written after CFS was in the kernel so the chapters are pretty up to date. Nick
_______________________________________________ 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
.
_______________________________________________ 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
-- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
On Thu, Apr 16, 2015 at 4:56 PM, Ruben Safir <ruben@mrbrklyn.com> wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
When everything else fails, I use grep ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node {" include/ include/linux/rbtree.h:struct rb_node { ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ -- Ricardo Ribalda
On 04/16/2015 11:07 AM, Ricardo Ribalda Delgado wrote:
On Thu, Apr 16, 2015 at 4:56 PM, Ruben Safir <ruben@mrbrklyn.com> wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
When everything else fails, I use grep
ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node {" include/ include/linux/rbtree.h:struct rb_node { ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$
yeah ...
On 04/16/2015 11:07 AM, Ricardo Ribalda Delgado wrote:
On Thu, Apr 16, 2015 at 4:56 PM, Ruben Safir <ruben@mrbrklyn.com> wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
When everything else fails, I use grep
ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node {" include/ include/linux/rbtree.h:struct rb_node { ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$
although in theory that only works if all your defined files are in your current subtree I wish I understood what the tags file says. It is like autoconf. It can take a lifetime to master the syntax. Ruben
On Thu, Apr 16, 2015 at 5:12 PM, Ruben Safir <ruben@mrbrklyn.com> wrote:
On 04/16/2015 11:07 AM, Ricardo Ribalda Delgado wrote:
When everything else fails, I use grep
ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node {" include/ include/linux/rbtree.h:struct rb_node { ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$
although in theory that only works if all your defined files are in your current subtree
"git grep" works recursively "git -r" also
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
Please use this: Linux 2.6.11 and later <http://lxr.linux.no/linux> At the top right there is a text box please type what your searching for, in this rb_node. It will show you on the right the search results. The Structure is defined here: include/linux/rbtree.h, line 35 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L35> and here it is in case you have difficulties: struct rb_node <http://lxr.linux.no/linux+*/+code=rb_node> { 36 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L36> unsigned long __rb_parent_color <http://lxr.linux.no/linux+*/+code=__rb_parent_color>; 37 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L37> struct rb_node <http://lxr.linux.no/linux+*/+code=rb_node> *rb_right <http://lxr.linux.no/linux+*/+code=rb_right>; 38 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L38> struct rb_node <http://lxr.linux.no/linux+*/+code=rb_node> *rb_left <http://lxr.linux.no/linux+*/+code=rb_left>; 39 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L39>} __attribute__ <http://lxr.linux.no/linux+*/+code=__attribute__>((aligned <http://lxr.linux.no/linux+*/+code=aligned>(sizeof(long)))); 40 <http://lxr.linux.no/linux+*/include/linux/rbtree.h#L40> /* The alignment might seem pointless, but allegedly CRIS needs it */ Thank's - Aruna
Ruben
On Thu, Apr 09, 2015 at 10:52:03PM -0400, nick wrote:
On 2015-04-09 10:12 PM, Ruben Safir wrote:
On 04/09/2015 10:00 PM, nick wrote:
On 2015-04-09 09:51 PM, Ruben Safir wrote:
It is passover so I've read over much of this text, but I have to say that in general, I'm way ahead of this book. Although I have limited knowledge of Kernel technology in the specific, the C code, data structs, and programming concepts are spoon feed in this text and its wasting too much time with words that are more easily explained with coding examples and UML charts. I don't need a chapter explaining
how
to use ps and the basis of Unix architecture. This text is targeted to a different audience, and FWIW, I'm not certain it does a good job of that either. The guys who write these texts fall in love with their own voices. I know, I've suffered this disease myself when I've written tech articles and books.
I can''t recommend this book to anyone. Anyone who doesn't understand the basics of I/O processer blocks is not going to understand
static void update_curr(struct cfs_rq *cfs_rq)
and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well enough for coders unfamiliar with the kernel data structs of which BTW struct cfs_rq is not one defined in the text.
:(
I'm looking for something more like this, but flushed out more as a textbook
http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index.... ,
and some mentoring, I hope.
Ruben
Ruben, The book is for an intro to the kernel not a complete walk through of each subsystem. If that is the case,why not read the subsystem code and docs in the kernel. I am a novice myself in terms of patch and coding experience but will be glad to explain the code as I have read lots of it.
Thank you nick. Yes, I downloaded the entire source from Kernel.org and it is sitting on both my laptop and in virtual machines where I have already compiled some stuff and not broken my VMs yets :)
I'm looking over /home/ruben/linux-3.19.3/Documentation/scheduler [ruben@stat13 scheduler]$ ls
00-INDEX sched-deadline.txt sched-rt-group.txt media=legal -o sides=two-sided-long-edg sched-design-CFS.txt sched-stats.txt sched-arch.txt sched-domains.txt sched-bwc.txt sched-nice-design.txt
I also see in the code there is significant documentation.
Right now I am trying to figure out what is the relationship between struct sched_entity and struct cfs_rq and struct rq_of
why do we have both??
The way that these structures are related is sched_enity is the entity for the task's scheduling information or the task_struct of the a excuting process to be exact. Furthermore cfs_rq is the runquenue on which the task is running or selected to run on by schedule,the main scheduling function of the kernel. Finally here is the function definition for rq_of to answer your question, static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } Before asking questions again like this please look into either using lxr or ctags to navigate the kernel tree for answers as can be faster then waiting for me or someone else to respond. Thanks, Nick
there is a cast in update_curr u64 now = rq_of(cfs_rq)->clock;
or is rq_of a function that returns a pointer is a struct that I missed?
Nick
On 03/22/2015 08:35 PM, nick wrote:
On 2015-03-22 08:05 PM, Ruben Safir wrote:
On 03/22/2015 07:30 PM, nick wrote:
I would recommend reading Chapters 3 and 4 of Linux Kernel
Development by Robert Love
as when I was learning the scheduler and process management
how much has the scheduler changed since then. It was completely overhauled when the CFS was created
The 3rd edition of this book was written after CFS was in the kernel so the chapters are pretty up to date. Nick
_______________________________________________ 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
.
_______________________________________________ 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
-- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com
DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com
Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
On 04/16/2015 11:10 AM, Aruna Hewapathirane wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
Please use this: Linux 2.6.11 and later <http://lxr.linux.no/linux>
91 responses is not a useful search...
I find that the free electrons LXR has the best search capabilities: http://lxr.free-electrons.com/source/include/linux/rbtree.h#L35 -M On Thu, Apr 16, 2015 at 10:56 AM, Ruben Safir <ruben@mrbrklyn.com> wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
Ruben
On Thu, Apr 09, 2015 at 10:52:03PM -0400, nick wrote:
On 2015-04-09 10:12 PM, Ruben Safir wrote:
On 04/09/2015 10:00 PM, nick wrote:
On 2015-04-09 09:51 PM, Ruben Safir wrote:
It is passover so I've read over much of this text, but I have to say that in general, I'm way ahead of this book. Although I have limited knowledge of Kernel technology in the specific, the C code, data structs, and programming concepts are spoon feed in this text and its wasting too much time with words that are more easily explained with coding examples and UML charts. I don't need a chapter explaining
how
to use ps and the basis of Unix architecture. This text is targeted to a different audience, and FWIW, I'm not certain it does a good job of that either. The guys who write these texts fall in love with their own voices. I know, I've suffered this disease myself when I've written tech articles and books.
I can''t recommend this book to anyone. Anyone who doesn't understand the basics of I/O processer blocks is not going to understand
static void update_curr(struct cfs_rq *cfs_rq)
and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well enough for coders unfamiliar with the kernel data structs of which BTW struct cfs_rq is not one defined in the text.
:(
I'm looking for something more like this, but flushed out more as a textbook
http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index.... ,
and some mentoring, I hope.
Ruben
Ruben, The book is for an intro to the kernel not a complete walk through of each subsystem. If that is the case,why not read the subsystem code and docs in the kernel. I am a novice myself in terms of patch and coding experience but will be glad to explain the code as I have read lots of it.
Thank you nick. Yes, I downloaded the entire source from Kernel.org and it is sitting on both my laptop and in virtual machines where I have already compiled some stuff and not broken my VMs yets :)
I'm looking over /home/ruben/linux-3.19.3/Documentation/scheduler [ruben@stat13 scheduler]$ ls
00-INDEX sched-deadline.txt sched-rt-group.txt media=legal -o sides=two-sided-long-edg sched-design-CFS.txt sched-stats.txt sched-arch.txt sched-domains.txt sched-bwc.txt sched-nice-design.txt
I also see in the code there is significant documentation.
Right now I am trying to figure out what is the relationship between struct sched_entity and struct cfs_rq and struct rq_of
why do we have both??
The way that these structures are related is sched_enity is the entity for the task's scheduling information or the task_struct of the a excuting process to be exact. Furthermore cfs_rq is the runquenue on which the task is running or selected to run on by schedule,the main scheduling function of the kernel. Finally here is the function definition for rq_of to answer your question, static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } Before asking questions again like this please look into either using lxr or ctags to navigate the kernel tree for answers as can be faster then waiting for me or someone else to respond. Thanks, Nick
there is a cast in update_curr u64 now = rq_of(cfs_rq)->clock;
or is rq_of a function that returns a pointer is a struct that I missed?
Nick
On 03/22/2015 08:35 PM, nick wrote:
On 2015-03-22 08:05 PM, Ruben Safir wrote:
On 03/22/2015 07:30 PM, nick wrote:
I would recommend reading Chapters 3 and 4 of Linux Kernel
Development by Robert Love
as when I was learning the scheduler and process management
how much has the scheduler changed since then. It was completely overhauled when the CFS was created
The 3rd edition of this book was written after CFS was in the kernel so the chapters are pretty up to date. Nick
_______________________________________________ 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
.
_______________________________________________ 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
-- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com
DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com
Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies-bounces@kernelnewbies.org] On Behalf Of Mark P Sent: Thursday, April 16, 2015 8:12 AM To: Ruben Safir Cc: nick; kernelnewbies@kernelnewbies.org Subject: Re: Kernel thread scheduling
I find that the free electrons LXR has the best search capabilities:
http://lxr.free-electrons.com/source/include/linux/rbtree.h#L35 -M
Those interested in kernel source browsers might want to check out the code browser available at https://scan.coverity.com. Coverity does static code analysis and sells a product to do so, but they do regular scans of popular open source projects. Most of their focus is on finding and reporting defects, but the code browser they have created to do so is far beyond anything else I've found out there. Getting to it is a little awkward, you first need to sign up for an account (I got mine for free), then browse to the linux kernel project and select a defect to get into the browser. But once there, click the folder icon at the top left of the code window and select a source file. All of function names, variable names, structure names and structure field names are hyperlinks. Left click on one of them, click the little down arrow and select from the menu to list definitions, references, etc. You do need to find a reference to the token in question using some other browser like LXR, Coverity's doesn't seem to have a search button for that, but once located the cross-referencing provided is better than what I've seen in other text matching browsers like LXR, cscope, etc. It's particular good when you are trying to understand how a given field of a structure is used. Say you want to find out how a structure field named "lock" in some structure named "foo" is referenced. Find the definition of struct foo, click on the lock field and list references. It will show all the references to struct foo's lock but NOT show the thousands of references to all of the other fields named "lock" in other structures. That is something no other browser does, at least none that I am aware of. Jeff Haran
On 04/16/2015 12:31 PM, Jeff Haran wrote:
From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies-bounces@kernelnewbies.org] On Behalf Of Mark P Sent: Thursday, April 16, 2015 8:12 AM To: Ruben Safir Cc: nick; kernelnewbies@kernelnewbies.org Subject: Re: Kernel thread scheduling
I find that the free electrons LXR has the best search capabilities:
http://lxr.free-electrons.com/source/include/linux/rbtree.h#L35 -M
Those interested in kernel source browsers might want to check out the code browser available at https://scan.coverity.com.
Coverity does static code analysis and sells a product to do so, but they do regular scans of popular open source projects. Most of their focus is on finding and reporting defects, but the code browser they have created to do so is far beyond anything else I've found out there. Getting to it is a little awkward, you first need to sign up for an account (I got mine for free), then browse to the linux kernel project and select a defect to get into the browser. But once there, click the folder icon at the top left of the code window and select a source file. All of function names, variable names, structure names and structure field names are hyperlinks. Left click on one of them, click the little down arrow and select from the menu to list definitions, references, etc.
You do need to find a reference to the token in question using some other browser like LXR, Coverity's doesn't seem to have a search button for that, but once located the cross-referencing provided is better than what I've seen in other text matching browsers like LXR, cscope, etc. It's particular good when you are trying to understand how a given field of a structure is used. Say you want to find out how a structure field named "lock" in some structure named "foo" is referenced. Find the definition of struct foo, click on the lock field and list references. It will show all the references to struct foo's lock but NOT show the thousands of references to all of the other fields named "lock" in other structures. That is something no other browser does, at least none that I am aware of.
Jeff Haran
Is it free software? Can I download it? How is it better than grep and sed? Does it work better than ctags? How can I get it to ingrate with vim? First off, if it is not available as free Software, then I won't use it.
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-----Original Message----- From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies- bounces@kernelnewbies.org] On Behalf Of Ruben Safir Sent: Thursday, April 16, 2015 10:09 AM To: kernelnewbies@kernelnewbies.org Subject: Re: Kernel thread scheduling
On 04/16/2015 12:31 PM, Jeff Haran wrote:
From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies-bounces@kernelnewbies.org] On Behalf Of Mark P Sent: Thursday, April 16, 2015 8:12 AM To: Ruben Safir Cc: nick; kernelnewbies@kernelnewbies.org Subject: Re: Kernel thread scheduling
I find that the free electrons LXR has the best search capabilities:
http://lxr.free-electrons.com/source/include/linux/rbtree.h#L35 -M
Those interested in kernel source browsers might want to check out the code browser available at https://scan.coverity.com.
Coverity does static code analysis and sells a product to do so, but they do regular scans of popular open source projects. Most of their focus is on finding and reporting defects, but the code browser they have created to do so is far beyond anything else I've found out there. Getting to it is a little awkward, you first need to sign up for an account (I got mine for free), then browse to the linux kernel project and select a defect to get into the browser. But once there, click the folder icon at the top left of the code window and select a source file. All of function names, variable names, structure names and structure field names are hyperlinks. Left click on one of them, click the little down arrow and select from the menu to list definitions, references, etc.
You do need to find a reference to the token in question using some other browser like LXR, Coverity's doesn't seem to have a search button for that, but once located the cross-referencing provided is better than what I've seen in other text matching browsers like LXR, cscope, etc. It's particular good when you are trying to understand how a given field of a structure is used. Say you want to find out how a structure field named "lock" in some structure named "foo" is referenced. Find the definition of struct foo, click on the lock field and list references. It will show all the references to struct foo's lock but NOT show the thousands of references to all of the other fields named "lock" in other structures. That is something no other browser does, at least none that I am aware of.
Jeff Haran
Is it free software? Can I download it?
The web site is free to use. The code that runs it is proprietary.
How is it better than grep and sed? Does it work better than ctags?
Grep, sed, ctags, cscope, etc. can only find references based on text matches. C allows duplicate field names across structure definitions. When using text based browsers to look for references to C structure field names on a large project like linux such searches yield lots of false positives, thousands of them in some cases. Coverity's browser on the other hand seems to understand C syntax. When looking for references so say struct foo's lock field, it won't show you references to struct bar's lock field. Other tools can't tell the difference.
How can I get it to ingrate with vim?
You can't so far as I know.
First off, if it is not available as free Software, then I won't use it.
That is of course your choice to make. Others may come to different conclusions. I use www.google.com on a regular basis even though I can't download it. Jeff Haran
First off, if it is not available as free Software, then I won't use it.
That is of course your choice to make.
And it is the correct decision to make. People who make another decision would not care about the damage they do to themselves and others by promoting the use of a proprietary system to access and learn about a free software project devised to intentionally do just the opposite and to give people access to code and ownership of their digital system. Why would someone sell that freedom for a minor convenience. This has been hashed. If everyone depended on this Software as a Service then you would have a nice walled garden to the Kernel Code. That would be a nice for you __maybe__, but it would be bad for the rest of us. https://www.gnu.org/philosophy/who-does-that-server-really-serve.html
Others may come to different conclusions. I use www.google.com on a regular basis even though I can't download it.
That is not even a good analogy. But for what it is worth, SOS is killing free software on the google platform altogether and it is a tragedy... it is killing Free Software and choking the future of development.
Jeff Haran
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-- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
On Thu, 16 Apr 2015 14:28:59 -0400, Ruben Safir said:
Others may come to different conclusions. I use www.google.com on a regular basis even though I can't download it.
That is not even a good analogy.
We're comparing closed Coverty-as-a-service with closed Google-as-a-service. Seems like a good analogy to me. I'm failing to see the moral difference between using Google SaaS to look to see if anybody else has reported a particular kernel error and using Coverty SaaS to examine kernel code. As you yourself said:
If everyone depended on this Software as a Service then you would have a nice walled garden to the Kernel Code.
Why do you object to Coverty when Google is almost certainly more depended on by kernel developers?
-----Original Message----- From: Valdis.Kletnieks@vt.edu [mailto:Valdis.Kletnieks@vt.edu] Sent: Thursday, April 16, 2015 11:48 AM To: Ruben Safir Cc: Jeff Haran; kernelnewbies@kernelnewbies.org Subject: Re: Kernel thread scheduling
On Thu, 16 Apr 2015 14:28:59 -0400, Ruben Safir said:
Others may come to different conclusions. I use www.google.com on a regular basis even though I can't download it.
That is not even a good analogy.
We're comparing closed Coverty-as-a-service with closed Google-as-a- service. Seems like a good analogy to me.
I'm failing to see the moral difference between using Google SaaS to look to see if anybody else has reported a particular kernel error and using Coverty SaaS to examine kernel code.
As you yourself said:
If everyone depended on this Software as a Service then you would have a nice walled garden to the Kernel Code.
Why do you object to Coverty when Google is almost certainly more depended on by kernel developers?
Not only that, but demonizing Coverity over this is quite unfair. They provide for free to the world the results of their static code analysis of many open source projects, Linux included. Granted, Coverity's system isn't perfect, it does generate false positives but I know from personally quite embarrassing experience that it does find real bugs in code that I've written and looked at hundreds of times that I didn't see and its pointing out to anybody who would care to look thousands of potential kernel bugs. They also have this posterior-kicking code browser that's better than all of the free competition that I know of. If somebody knows of any better, please let me know. I often read emails on this list from people looking to help and get started in kernel development. Well, here's a good place to start. Submit patches to fix some of those Coverity identified kernel bugs. Some of them will be false positives, but some of them will be the real thing. And just for the record, I have no financial interest in Coverity or its parent company. I've been a user of their system at a couple of companies I've worked for now, but that and my usage of their free service is the only connection I have with them. Jeff Haran
Am 2015-04-16 23:41, schrieb Jeff Haran:
I often read emails on this list from people looking to help and get started in kernel development. Well, here's a good place to start. Submit patches to fix some of those Coverity identified kernel bugs. Some of them will be false positives, but some of them will be the real thing.
I totally agree. If there are people that do not want to use non-free software for static code analysis (even as a service) they can instead go for smatch[0]. Smatch is part of the 0-day Kernel test infrastructure[1] of Intel and is open source software. I've written a short blog post on how to use smatch here[2]. Any feedback and/or criticism would be appreciated. Cheers, Silvan [0] http://smatch.sourceforge.net/ [1] https://lists.01.org/mailman/listinfo/kbuild [2] http://sillymon.ch/posts/smatchusage.html
And just for the record, I have no financial interest in Coverity or its parent company. I've been a user of their system at a couple of companies I've worked for now, but that and my usage of their free service is the only connection I have with them.
Jeff Haran
Jeff, FWIW, I have no objection to a financial interest. I want you to make as much many as you can This is not an issue of money. Ruben -- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
On 04/16/2015 02:47 PM, Valdis.Kletnieks@vt.edu wrote:
We're comparing closed Coverty-as-a-service with closed Google-as-a-service. Seems like a good analogy to me.
well it isn't. It is not demonizing them to state the facts. First of all, search engines do something you can't do with software, which is crawl the internet. The correct analogy is what google is doing with android, which indeed is repulsive because it is inhibiting access and development on the platform, and then worse than that, claiming that it is all "open" when really it is not. http://arstechnica.com/gadgets/2013/10/googles-iron-grip-on-android-controll... I have the source code for the kernel here. If Coventry would be interested in selling me a free software of their application, I might be interested. But I'm not interested in putting kernel tools behind slavewalls. That is exactly the opposite of what I want to do and defies my very Raison E'Stat for studying the Linux Kernel.... nono. If you find this Demonizing, it is not I who does this, it is facts stated forthrightly and dispassionately. Someone who uses closed proprietary software as a service to access the Linux Kernel Source is cutting off the very air to free software development by supporting non-free tools that compete with free tools in learning about the source code. Using free software tools is not a technological decision. It is a political decision (as all decisions ultimately are). It is a decision to exercise freedom over a __lack__ of freedom. Aside from that, the question of google is irrelevant to this conversation and is just a distraction. Tow wrongs don't make a right. A company that has a search engine that uses published free software would be much more desirable than one that doesn't do that. No one wants to penalize anyone for selling software services. But that is not reason to abandon free software tools for the studying of the kernel in order to adopt a proprietary scheme of secret software sold as a service. That would just be irrational. Ruben
On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
I run: make ctags run vim type: :ts rb_node then I scanned the list for things that are from include/linux and found this 20 F s rb_node include/linux/rbtree.h struct rb_node { I select 20 and it takes me to include/linux/rbtree.h and puts me at the line containing this: struct rb_node { unsigned long __rb_parent_color; struct rb_node *rb_right; struct rb_node *rb_left; } __attribute__((aligned(sizeof(long)))); /* The alignment might seem pointless, but allegedly CRIS needs it */
On 04/16/2015 02:32 PM, John de la Garza wrote:
On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
THANK YOU - This is for my archive of useful Linux Hints!!
How do you search these things out?
I run: make ctags
run vim
type: :ts rb_node
then I scanned the list for things that are from include/linux
and found this 20 F s rb_node include/linux/rbtree.h struct rb_node {
I select 20 and it takes me to include/linux/rbtree.h
and puts me at the line containing this:
struct rb_node { unsigned long __rb_parent_color; struct rb_node *rb_right; struct rb_node *rb_left; } __attribute__((aligned(sizeof(long)))); /* The alignment might seem pointless, but allegedly CRIS needs it */
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On 04/16/2015 02:32 PM, John de la Garza wrote:
On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
That is truly beautiful. Is that documented anywhere in plain english? Ruben
I run: make ctags
run vim
type: :ts rb_node
then I scanned the list for things that are from include/linux
and found this 20 F s rb_node include/linux/rbtree.h struct rb_node {
I select 20 and it takes me to include/linux/rbtree.h
and puts me at the line containing this:
struct rb_node { unsigned long __rb_parent_color; struct rb_node *rb_right; struct rb_node *rb_left; } __attribute__((aligned(sizeof(long)))); /* The alignment might seem pointless, but allegedly CRIS needs it */
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On Thu, Apr 16, 2015 at 02:42:07PM -0400, Ruben Safir wrote:
On 04/16/2015 02:32 PM, John de la Garza wrote:
On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
I'm trying to find rb_node's structure and I can't find it with ctags or in the http://lxr.linux.no website.
How do you search these things out?
That is truly beautiful. Is that documented anywhere in plain english?
If you mean the tag search functionality, yes. See below.
I run: make ctags
Documentation for this you can find by running "make help" at the root of the Kernel source tree.
run vim
type: :ts rb_node
This functionality is documented in Vim itself. To access the relevant documentation just run :help tags There is also the "cscope" program that can give you information about which functions call and are being called by which other functions. It has its own man page. Cheers, Silvan
then I scanned the list for things that are from include/linux
and found this 20 F s rb_node include/linux/rbtree.h struct rb_node {
I select 20 and it takes me to include/linux/rbtree.h
and puts me at the line containing this:
struct rb_node { unsigned long __rb_parent_color; struct rb_node *rb_right; struct rb_node *rb_left; } __attribute__((aligned(sizeof(long)))); /* The alignment might seem pointless, but allegedly CRIS needs it */
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participants (9)
-
Aruna Hewapathirane -
Jeff Haran -
John de la Garza -
Mark P -
nick -
Ricardo Ribalda Delgado -
Ruben Safir -
Silvan Jegen -
Valdis.Kletnieks＠vt.edu