Re: [PATCH 1/7] cgroup: fix and update documentation
On Feb 18, 2008 12:39 AM, Li Zefan <[EMAIL PROTECTED]> wrote: > Misc fixes and updates, make the doc consistent with current > cgroup implementation. > > Signed-off-by: Li Zefan <[EMAIL PROTECTED]> Acked-by: Paul Menage <[EMAIL PROTECTED]> Thanks for these cleanups. Paul > --- > Documentation/cgroups.txt | 66 ++-- > 1 files changed, 33 insertions(+), 33 deletions(-) > > diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt > index 42d7c4c..31d12e2 100644 > > --- a/Documentation/cgroups.txt > +++ b/Documentation/cgroups.txt > @@ -28,7 +28,7 @@ CONTENTS: > 4. Questions > > 1. Control Groups > -== > += > > 1.1 What are cgroups ? > -- > @@ -143,10 +143,10 @@ proliferation of such cgroups. > > Also lets say that the administrator would like to give enhanced network > access temporarily to a student's browser (since it is night and the user > -wants to do online gaming :) OR give one of the students simulation > +wants to do online gaming :)) OR give one of the students simulation > apps enhanced CPU power, > > -With ability to write pids directly to resource classes, its just a > +With ability to write pids directly to resource classes, it's just a > matter of : > > # echo pid > /mnt/network//tasks > @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup > file system > containing the following files describing that cgroup: > > - tasks: list of tasks (by pid) attached to that cgroup > - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? > + - releasable flag: cgroup currently removeable? > + - notify_on_release flag: run the release agent on exit? > + - release_agent: the path to use for release notifications (this file > + exists in the top cgroup only) > > Other subsystems such as cpusets may add additional files in each > -cgroup dir > +cgroup dir. > > New cgroups are created using the mkdir system call or shell > command. The properties of a cgroup, such as its flags, are > @@ -257,7 +260,7 @@ performance. > To allow access from a cgroup to the css_sets (and hence tasks) > that comprise it, a set of cg_cgroup_link objects form a lattice; > each cg_cgroup_link is linked into a list of cg_cgroup_links for > -a single cgroup on its cont_link_list field, and a list of > +a single cgroup on its cgrp_link_list field, and a list of > cg_cgroup_links for a single css_set on its cg_link_list. > > Thus the set of tasks in a cgroup can be listed by iterating over > @@ -271,9 +274,6 @@ for cgroups, with a minimum of additional kernel code. > 1.4 What does notify_on_release do ? > > > -*** notify_on_release is disabled in the current patch set. It will be > -*** reactivated in a future patch in a less-intrusive manner > - > If the notify_on_release flag is enabled (1) in a cgroup, then > whenever the last task in the cgroup leaves (exits or attaches to > some other cgroup) and the last child cgroup of that cgroup > @@ -360,8 +360,8 @@ Now you want to do something with this cgroup. > > In this directory you can find several files: > # ls > -notify_on_release release_agent tasks > -(plus whatever files are added by the attached subsystems) > +notify_on_release releasable tasks > +(plus whatever files added by the attached subsystems) > > Now attach your shell to this cgroup: > # /bin/echo $$ > tasks > @@ -404,19 +404,13 @@ with a subsystem id which will be assigned by the > cgroup system. > Other fields in the cgroup_subsys object include: > > - subsys_id: a unique array index for the subsystem, indicating which > - entry in cgroup->subsys[] this subsystem should be > - managing. Initialized by cgroup_register_subsys(); prior to this > - it should be initialized to -1 > + entry in cgroup->subsys[] this subsystem should be managing. > > -- hierarchy: an index indicating which hierarchy, if any, this > - subsystem is currently attached to. If this is -1, then the > - subsystem is not attached to any hierarchy, and all tasks should be > - considered to be members of the subsystem's top_cgroup. It should > - be initialized to -1. > +- name: should be initialized to a unique subsystem name. Should be > + no longer than MAX_CGROUP_TYPE_NAMELEN. > > -- name: should be initialized to a unique subsystem name prior to > - calling cgroup_register_subsystem. Should be no longer than > - MAX_CGROUP_TYPE_NAMELEN > +- early_init: indicate if the subsystem needs early initialization > + at system boot. > > Each cgroup object created by the system has an array of pointers, > indexed by subsystem id; this pointer is entirely managed by the > @@ -434,8 +428,6 @@ situation. > See kernel/cgroup.c for more details. > > Subsystems can take/release the cgroup_mutex via the functions > -cgroup_lock()/cgroup_unlock(), and can > -take/release the callback_mutex via the functions >
Re: [PATCH 1/7] cgroup: fix and update documentation
On Feb 18, 2008 12:39 AM, Li Zefan [EMAIL PROTECTED] wrote: Misc fixes and updates, make the doc consistent with current cgroup implementation. Signed-off-by: Li Zefan [EMAIL PROTECTED] Acked-by: Paul Menage [EMAIL PROTECTED] Thanks for these cleanups. Paul --- Documentation/cgroups.txt | 66 ++-- 1 files changed, 33 insertions(+), 33 deletions(-) diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt index 42d7c4c..31d12e2 100644 --- a/Documentation/cgroups.txt +++ b/Documentation/cgroups.txt @@ -28,7 +28,7 @@ CONTENTS: 4. Questions 1. Control Groups -== += 1.1 What are cgroups ? -- @@ -143,10 +143,10 @@ proliferation of such cgroups. Also lets say that the administrator would like to give enhanced network access temporarily to a student's browser (since it is night and the user -wants to do online gaming :) OR give one of the students simulation +wants to do online gaming :)) OR give one of the students simulation apps enhanced CPU power, -With ability to write pids directly to resource classes, its just a +With ability to write pids directly to resource classes, it's just a matter of : # echo pid /mnt/network/new_class/tasks @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup file system containing the following files describing that cgroup: - tasks: list of tasks (by pid) attached to that cgroup - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? + - releasable flag: cgroup currently removeable? + - notify_on_release flag: run the release agent on exit? + - release_agent: the path to use for release notifications (this file + exists in the top cgroup only) Other subsystems such as cpusets may add additional files in each -cgroup dir +cgroup dir. New cgroups are created using the mkdir system call or shell command. The properties of a cgroup, such as its flags, are @@ -257,7 +260,7 @@ performance. To allow access from a cgroup to the css_sets (and hence tasks) that comprise it, a set of cg_cgroup_link objects form a lattice; each cg_cgroup_link is linked into a list of cg_cgroup_links for -a single cgroup on its cont_link_list field, and a list of +a single cgroup on its cgrp_link_list field, and a list of cg_cgroup_links for a single css_set on its cg_link_list. Thus the set of tasks in a cgroup can be listed by iterating over @@ -271,9 +274,6 @@ for cgroups, with a minimum of additional kernel code. 1.4 What does notify_on_release do ? -*** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner - If the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup leaves (exits or attaches to some other cgroup) and the last child cgroup of that cgroup @@ -360,8 +360,8 @@ Now you want to do something with this cgroup. In this directory you can find several files: # ls -notify_on_release release_agent tasks -(plus whatever files are added by the attached subsystems) +notify_on_release releasable tasks +(plus whatever files added by the attached subsystems) Now attach your shell to this cgroup: # /bin/echo $$ tasks @@ -404,19 +404,13 @@ with a subsystem id which will be assigned by the cgroup system. Other fields in the cgroup_subsys object include: - subsys_id: a unique array index for the subsystem, indicating which - entry in cgroup-subsys[] this subsystem should be - managing. Initialized by cgroup_register_subsys(); prior to this - it should be initialized to -1 + entry in cgroup-subsys[] this subsystem should be managing. -- hierarchy: an index indicating which hierarchy, if any, this - subsystem is currently attached to. If this is -1, then the - subsystem is not attached to any hierarchy, and all tasks should be - considered to be members of the subsystem's top_cgroup. It should - be initialized to -1. +- name: should be initialized to a unique subsystem name. Should be + no longer than MAX_CGROUP_TYPE_NAMELEN. -- name: should be initialized to a unique subsystem name prior to - calling cgroup_register_subsystem. Should be no longer than - MAX_CGROUP_TYPE_NAMELEN +- early_init: indicate if the subsystem needs early initialization + at system boot. Each cgroup object created by the system has an array of pointers, indexed by subsystem id; this pointer is entirely managed by the @@ -434,8 +428,6 @@ situation. See kernel/cgroup.c for more details. Subsystems can take/release the cgroup_mutex via the functions -cgroup_lock()/cgroup_unlock(), and can -take/release the callback_mutex via the functions cgroup_lock()/cgroup_unlock(). Accessing a task's cgroup pointer may be done in the following ways: @@ -444,7 +436,7 @@ Accessing a task's
Re: [PATCH 1/7] cgroup: fix and update documentation
Misc fixes and updates, make the doc consistent with current cgroup implementation. Signed-off-by: Li Zefan <[EMAIL PROTECTED]> --- Documentation/cgroups.txt | 66 ++-- 1 files changed, 33 insertions(+), 33 deletions(-) diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt index 42d7c4c..31d12e2 100644 --- a/Documentation/cgroups.txt +++ b/Documentation/cgroups.txt @@ -28,7 +28,7 @@ CONTENTS: 4. Questions 1. Control Groups -== += 1.1 What are cgroups ? -- @@ -143,10 +143,10 @@ proliferation of such cgroups. Also lets say that the administrator would like to give enhanced network access temporarily to a student's browser (since it is night and the user -wants to do online gaming :) OR give one of the students simulation +wants to do online gaming :)) OR give one of the students simulation apps enhanced CPU power, -With ability to write pids directly to resource classes, its just a +With ability to write pids directly to resource classes, it's just a matter of : # echo pid > /mnt/network//tasks @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup file system containing the following files describing that cgroup: - tasks: list of tasks (by pid) attached to that cgroup - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? + - releasable flag: cgroup currently removeable? + - notify_on_release flag: run the release agent on exit? + - release_agent: the path to use for release notifications (this file + exists in the top cgroup only) Other subsystems such as cpusets may add additional files in each -cgroup dir +cgroup dir. New cgroups are created using the mkdir system call or shell command. The properties of a cgroup, such as its flags, are @@ -257,7 +260,7 @@ performance. To allow access from a cgroup to the css_sets (and hence tasks) that comprise it, a set of cg_cgroup_link objects form a lattice; each cg_cgroup_link is linked into a list of cg_cgroup_links for -a single cgroup on its cont_link_list field, and a list of +a single cgroup on its cgrp_link_list field, and a list of cg_cgroup_links for a single css_set on its cg_link_list. Thus the set of tasks in a cgroup can be listed by iterating over @@ -271,9 +274,6 @@ for cgroups, with a minimum of additional kernel code. 1.4 What does notify_on_release do ? -*** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner - If the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup leaves (exits or attaches to some other cgroup) and the last child cgroup of that cgroup @@ -360,8 +360,8 @@ Now you want to do something with this cgroup. In this directory you can find several files: # ls -notify_on_release release_agent tasks -(plus whatever files are added by the attached subsystems) +notify_on_release releasable tasks +(plus whatever files added by the attached subsystems) Now attach your shell to this cgroup: # /bin/echo $$ > tasks @@ -404,19 +404,13 @@ with a subsystem id which will be assigned by the cgroup system. Other fields in the cgroup_subsys object include: - subsys_id: a unique array index for the subsystem, indicating which - entry in cgroup->subsys[] this subsystem should be - managing. Initialized by cgroup_register_subsys(); prior to this - it should be initialized to -1 + entry in cgroup->subsys[] this subsystem should be managing. -- hierarchy: an index indicating which hierarchy, if any, this - subsystem is currently attached to. If this is -1, then the - subsystem is not attached to any hierarchy, and all tasks should be - considered to be members of the subsystem's top_cgroup. It should - be initialized to -1. +- name: should be initialized to a unique subsystem name. Should be + no longer than MAX_CGROUP_TYPE_NAMELEN. -- name: should be initialized to a unique subsystem name prior to - calling cgroup_register_subsystem. Should be no longer than - MAX_CGROUP_TYPE_NAMELEN +- early_init: indicate if the subsystem needs early initialization + at system boot. Each cgroup object created by the system has an array of pointers, indexed by subsystem id; this pointer is entirely managed by the @@ -434,8 +428,6 @@ situation. See kernel/cgroup.c for more details. Subsystems can take/release the cgroup_mutex via the functions -cgroup_lock()/cgroup_unlock(), and can -take/release the callback_mutex via the functions cgroup_lock()/cgroup_unlock(). Accessing a task's cgroup pointer may be done in the following ways: @@ -444,7 +436,7 @@ Accessing a task's cgroup pointer may be done in the following ways: - inside an rcu_read_lock() section via rcu_dereference() 3.3 Subsystem API --- +- Each subsystem should: @@ -455,7
Re: [PATCH 1/7] cgroup: fix and update documentation
Paul Jackson wrote: > Li Zefan wrote: >> *** notify_on_release is disabled in the current patch set. It will be >> -*** reactivated in a future patch in a less-intrusive manner >> +*** reactivated in a future patch in a less-intrusive manner. > > Someone should verify this, but I'm pretty sure that notify_on_release > is now working ... no longer disabled. I believe the above line from > the documentation is out of date. > Aha, it does work now. I tried it but it didn't seem to work, maybe I didn't something wrong. I'll resend a new patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/7] cgroup: fix and update documentation
Paul Jackson wrote: Li Zefan wrote: *** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner +*** reactivated in a future patch in a less-intrusive manner. Someone should verify this, but I'm pretty sure that notify_on_release is now working ... no longer disabled. I believe the above line from the documentation is out of date. Aha, it does work now. I tried it but it didn't seem to work, maybe I didn't something wrong. I'll resend a new patch. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/7] cgroup: fix and update documentation
Misc fixes and updates, make the doc consistent with current cgroup implementation. Signed-off-by: Li Zefan [EMAIL PROTECTED] --- Documentation/cgroups.txt | 66 ++-- 1 files changed, 33 insertions(+), 33 deletions(-) diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt index 42d7c4c..31d12e2 100644 --- a/Documentation/cgroups.txt +++ b/Documentation/cgroups.txt @@ -28,7 +28,7 @@ CONTENTS: 4. Questions 1. Control Groups -== += 1.1 What are cgroups ? -- @@ -143,10 +143,10 @@ proliferation of such cgroups. Also lets say that the administrator would like to give enhanced network access temporarily to a student's browser (since it is night and the user -wants to do online gaming :) OR give one of the students simulation +wants to do online gaming :)) OR give one of the students simulation apps enhanced CPU power, -With ability to write pids directly to resource classes, its just a +With ability to write pids directly to resource classes, it's just a matter of : # echo pid /mnt/network/new_class/tasks @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup file system containing the following files describing that cgroup: - tasks: list of tasks (by pid) attached to that cgroup - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? + - releasable flag: cgroup currently removeable? + - notify_on_release flag: run the release agent on exit? + - release_agent: the path to use for release notifications (this file + exists in the top cgroup only) Other subsystems such as cpusets may add additional files in each -cgroup dir +cgroup dir. New cgroups are created using the mkdir system call or shell command. The properties of a cgroup, such as its flags, are @@ -257,7 +260,7 @@ performance. To allow access from a cgroup to the css_sets (and hence tasks) that comprise it, a set of cg_cgroup_link objects form a lattice; each cg_cgroup_link is linked into a list of cg_cgroup_links for -a single cgroup on its cont_link_list field, and a list of +a single cgroup on its cgrp_link_list field, and a list of cg_cgroup_links for a single css_set on its cg_link_list. Thus the set of tasks in a cgroup can be listed by iterating over @@ -271,9 +274,6 @@ for cgroups, with a minimum of additional kernel code. 1.4 What does notify_on_release do ? -*** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner - If the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup leaves (exits or attaches to some other cgroup) and the last child cgroup of that cgroup @@ -360,8 +360,8 @@ Now you want to do something with this cgroup. In this directory you can find several files: # ls -notify_on_release release_agent tasks -(plus whatever files are added by the attached subsystems) +notify_on_release releasable tasks +(plus whatever files added by the attached subsystems) Now attach your shell to this cgroup: # /bin/echo $$ tasks @@ -404,19 +404,13 @@ with a subsystem id which will be assigned by the cgroup system. Other fields in the cgroup_subsys object include: - subsys_id: a unique array index for the subsystem, indicating which - entry in cgroup-subsys[] this subsystem should be - managing. Initialized by cgroup_register_subsys(); prior to this - it should be initialized to -1 + entry in cgroup-subsys[] this subsystem should be managing. -- hierarchy: an index indicating which hierarchy, if any, this - subsystem is currently attached to. If this is -1, then the - subsystem is not attached to any hierarchy, and all tasks should be - considered to be members of the subsystem's top_cgroup. It should - be initialized to -1. +- name: should be initialized to a unique subsystem name. Should be + no longer than MAX_CGROUP_TYPE_NAMELEN. -- name: should be initialized to a unique subsystem name prior to - calling cgroup_register_subsystem. Should be no longer than - MAX_CGROUP_TYPE_NAMELEN +- early_init: indicate if the subsystem needs early initialization + at system boot. Each cgroup object created by the system has an array of pointers, indexed by subsystem id; this pointer is entirely managed by the @@ -434,8 +428,6 @@ situation. See kernel/cgroup.c for more details. Subsystems can take/release the cgroup_mutex via the functions -cgroup_lock()/cgroup_unlock(), and can -take/release the callback_mutex via the functions cgroup_lock()/cgroup_unlock(). Accessing a task's cgroup pointer may be done in the following ways: @@ -444,7 +436,7 @@ Accessing a task's cgroup pointer may be done in the following ways: - inside an rcu_read_lock() section via rcu_dereference() 3.3 Subsystem API --- +- Each subsystem should: @@ -455,7
Re: [PATCH 1/7] cgroup: fix and update documentation
Li Zefan wrote: > *** notify_on_release is disabled in the current patch set. It will be > -*** reactivated in a future patch in a less-intrusive manner > +*** reactivated in a future patch in a less-intrusive manner. Someone should verify this, but I'm pretty sure that notify_on_release is now working ... no longer disabled. I believe the above line from the documentation is out of date. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson <[EMAIL PROTECTED]> 1.940.382.4214 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 1/7] cgroup: fix and update documentation
Misc fixes and updates, make the doc consistent with current cgroup implementation. Signed-off-by: Li Zefan <[EMAIL PROTECTED]> --- Documentation/cgroups.txt | 65 +++- 1 files changed, 34 insertions(+), 31 deletions(-) diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt index 42d7c4c..dfadd75 100644 --- a/Documentation/cgroups.txt +++ b/Documentation/cgroups.txt @@ -28,7 +28,7 @@ CONTENTS: 4. Questions 1. Control Groups -== += 1.1 What are cgroups ? -- @@ -143,10 +143,10 @@ proliferation of such cgroups. Also lets say that the administrator would like to give enhanced network access temporarily to a student's browser (since it is night and the user -wants to do online gaming :) OR give one of the students simulation +wants to do online gaming :)) OR give one of the students simulation apps enhanced CPU power, -With ability to write pids directly to resource classes, its just a +With ability to write pids directly to resource classes, it's just a matter of : # echo pid > /mnt/network//tasks @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup file system containing the following files describing that cgroup: - tasks: list of tasks (by pid) attached to that cgroup - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? + - releasable flag: cgroup currently removeable? + - notify_on_release flag: run the release agent on exit? + - release_agent: the path to use for release notifications (this file + exists in the top cgroup only) Other subsystems such as cpusets may add additional files in each -cgroup dir +cgroup dir. New cgroups are created using the mkdir system call or shell command. The properties of a cgroup, such as its flags, are @@ -257,7 +260,7 @@ performance. To allow access from a cgroup to the css_sets (and hence tasks) that comprise it, a set of cg_cgroup_link objects form a lattice; each cg_cgroup_link is linked into a list of cg_cgroup_links for -a single cgroup on its cont_link_list field, and a list of +a single cgroup on its cgrp_link_list field, and a list of cg_cgroup_links for a single css_set on its cg_link_list. Thus the set of tasks in a cgroup can be listed by iterating over @@ -272,7 +275,7 @@ for cgroups, with a minimum of additional kernel code. *** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner +*** reactivated in a future patch in a less-intrusive manner. If the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup leaves (exits or attaches to @@ -360,8 +363,8 @@ Now you want to do something with this cgroup. In this directory you can find several files: # ls -notify_on_release release_agent tasks -(plus whatever files are added by the attached subsystems) +notify_on_release releasable tasks +(plus whatever files added by the attached subsystems) Now attach your shell to this cgroup: # /bin/echo $$ > tasks @@ -404,19 +407,13 @@ with a subsystem id which will be assigned by the cgroup system. Other fields in the cgroup_subsys object include: - subsys_id: a unique array index for the subsystem, indicating which - entry in cgroup->subsys[] this subsystem should be - managing. Initialized by cgroup_register_subsys(); prior to this - it should be initialized to -1 + entry in cgroup->subsys[] this subsystem should be managing. -- hierarchy: an index indicating which hierarchy, if any, this - subsystem is currently attached to. If this is -1, then the - subsystem is not attached to any hierarchy, and all tasks should be - considered to be members of the subsystem's top_cgroup. It should - be initialized to -1. +- name: should be initialized to a unique subsystem name. Should be + no longer than MAX_CGROUP_TYPE_NAMELEN. -- name: should be initialized to a unique subsystem name prior to - calling cgroup_register_subsystem. Should be no longer than - MAX_CGROUP_TYPE_NAMELEN +- early_init: indicate if the subsystem needs early initialization + at system boot. Each cgroup object created by the system has an array of pointers, indexed by subsystem id; this pointer is entirely managed by the @@ -434,8 +431,6 @@ situation. See kernel/cgroup.c for more details. Subsystems can take/release the cgroup_mutex via the functions -cgroup_lock()/cgroup_unlock(), and can -take/release the callback_mutex via the functions cgroup_lock()/cgroup_unlock(). Accessing a task's cgroup pointer may be done in the following ways: @@ -444,7 +439,7 @@ Accessing a task's cgroup pointer may be done in the following ways: - inside an rcu_read_lock() section via rcu_dereference() 3.3 Subsystem API --- +- Each subsystem should: @@ -455,7 +450,8 @@ Each subsystem may export the
[PATCH 1/7] cgroup: fix and update documentation
Misc fixes and updates, make the doc consistent with current cgroup implementation. Signed-off-by: Li Zefan [EMAIL PROTECTED] --- Documentation/cgroups.txt | 65 +++- 1 files changed, 34 insertions(+), 31 deletions(-) diff --git a/Documentation/cgroups.txt b/Documentation/cgroups.txt index 42d7c4c..dfadd75 100644 --- a/Documentation/cgroups.txt +++ b/Documentation/cgroups.txt @@ -28,7 +28,7 @@ CONTENTS: 4. Questions 1. Control Groups -== += 1.1 What are cgroups ? -- @@ -143,10 +143,10 @@ proliferation of such cgroups. Also lets say that the administrator would like to give enhanced network access temporarily to a student's browser (since it is night and the user -wants to do online gaming :) OR give one of the students simulation +wants to do online gaming :)) OR give one of the students simulation apps enhanced CPU power, -With ability to write pids directly to resource classes, its just a +With ability to write pids directly to resource classes, it's just a matter of : # echo pid /mnt/network/new_class/tasks @@ -227,10 +227,13 @@ Each cgroup is represented by a directory in the cgroup file system containing the following files describing that cgroup: - tasks: list of tasks (by pid) attached to that cgroup - - notify_on_release flag: run /sbin/cgroup_release_agent on exit? + - releasable flag: cgroup currently removeable? + - notify_on_release flag: run the release agent on exit? + - release_agent: the path to use for release notifications (this file + exists in the top cgroup only) Other subsystems such as cpusets may add additional files in each -cgroup dir +cgroup dir. New cgroups are created using the mkdir system call or shell command. The properties of a cgroup, such as its flags, are @@ -257,7 +260,7 @@ performance. To allow access from a cgroup to the css_sets (and hence tasks) that comprise it, a set of cg_cgroup_link objects form a lattice; each cg_cgroup_link is linked into a list of cg_cgroup_links for -a single cgroup on its cont_link_list field, and a list of +a single cgroup on its cgrp_link_list field, and a list of cg_cgroup_links for a single css_set on its cg_link_list. Thus the set of tasks in a cgroup can be listed by iterating over @@ -272,7 +275,7 @@ for cgroups, with a minimum of additional kernel code. *** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner +*** reactivated in a future patch in a less-intrusive manner. If the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup leaves (exits or attaches to @@ -360,8 +363,8 @@ Now you want to do something with this cgroup. In this directory you can find several files: # ls -notify_on_release release_agent tasks -(plus whatever files are added by the attached subsystems) +notify_on_release releasable tasks +(plus whatever files added by the attached subsystems) Now attach your shell to this cgroup: # /bin/echo $$ tasks @@ -404,19 +407,13 @@ with a subsystem id which will be assigned by the cgroup system. Other fields in the cgroup_subsys object include: - subsys_id: a unique array index for the subsystem, indicating which - entry in cgroup-subsys[] this subsystem should be - managing. Initialized by cgroup_register_subsys(); prior to this - it should be initialized to -1 + entry in cgroup-subsys[] this subsystem should be managing. -- hierarchy: an index indicating which hierarchy, if any, this - subsystem is currently attached to. If this is -1, then the - subsystem is not attached to any hierarchy, and all tasks should be - considered to be members of the subsystem's top_cgroup. It should - be initialized to -1. +- name: should be initialized to a unique subsystem name. Should be + no longer than MAX_CGROUP_TYPE_NAMELEN. -- name: should be initialized to a unique subsystem name prior to - calling cgroup_register_subsystem. Should be no longer than - MAX_CGROUP_TYPE_NAMELEN +- early_init: indicate if the subsystem needs early initialization + at system boot. Each cgroup object created by the system has an array of pointers, indexed by subsystem id; this pointer is entirely managed by the @@ -434,8 +431,6 @@ situation. See kernel/cgroup.c for more details. Subsystems can take/release the cgroup_mutex via the functions -cgroup_lock()/cgroup_unlock(), and can -take/release the callback_mutex via the functions cgroup_lock()/cgroup_unlock(). Accessing a task's cgroup pointer may be done in the following ways: @@ -444,7 +439,7 @@ Accessing a task's cgroup pointer may be done in the following ways: - inside an rcu_read_lock() section via rcu_dereference() 3.3 Subsystem API --- +- Each subsystem should: @@ -455,7 +450,8 @@ Each subsystem may export
Re: [PATCH 1/7] cgroup: fix and update documentation
Li Zefan wrote: *** notify_on_release is disabled in the current patch set. It will be -*** reactivated in a future patch in a less-intrusive manner +*** reactivated in a future patch in a less-intrusive manner. Someone should verify this, but I'm pretty sure that notify_on_release is now working ... no longer disabled. I believe the above line from the documentation is out of date. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson [EMAIL PROTECTED] 1.940.382.4214 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
