| Message ID | 1322242696-27682-11-git-send-email-glommer@parallels.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, 25 Nov 2011 15:38:16 -0200 Glauber Costa <glommer@parallels.com> wrote: > Since this code is still experimental, we are leaving the exact > details of how to move tasks between cgroups when kernel memory > accounting is used as future work. > > For now, we simply disallow movement if there are any pending > accounted memory. > > Signed-off-by: Glauber Costa <glommer@parallels.com> > CC: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com> > --- > mm/memcontrol.c | 23 ++++++++++++++++++++++- > 1 files changed, 22 insertions(+), 1 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 2df5d3c..ab7e57b 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -5451,10 +5451,19 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, > { > int ret = 0; > struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); > + struct mem_cgroup *from = mem_cgroup_from_task(p); > + > +#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_INET) > + if (from != mem && !mem_cgroup_is_root(from) && > + res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) { > + printk(KERN_WARNING "Can't move tasks between cgroups: " > + "Kernel memory held. task: %s\n", p->comm); > + return 1; > + } > +#endif Hmm, the kernel memory is not guaranteed as being held by the 'task' ? How about "Now, moving task between cgroup is disallowed while the source cgroup containes kmem reference." ? Hmm.. we need to fix this task-move/rmdir issue before production use. Thanks, -Kame -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/28/2011 02:32 AM, KAMEZAWA Hiroyuki wrote: > On Fri, 25 Nov 2011 15:38:16 -0200 > Glauber Costa<glommer@parallels.com> wrote: > >> Since this code is still experimental, we are leaving the exact >> details of how to move tasks between cgroups when kernel memory >> accounting is used as future work. >> >> For now, we simply disallow movement if there are any pending >> accounted memory. >> >> Signed-off-by: Glauber Costa<glommer@parallels.com> >> CC: Hiroyouki Kamezawa<kamezawa.hiroyu@jp.fujitsu.com> >> --- >> mm/memcontrol.c | 23 ++++++++++++++++++++++- >> 1 files changed, 22 insertions(+), 1 deletions(-) >> >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 2df5d3c..ab7e57b 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -5451,10 +5451,19 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, >> { >> int ret = 0; >> struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); >> + struct mem_cgroup *from = mem_cgroup_from_task(p); >> + >> +#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM)&& defined(CONFIG_INET) >> + if (from != mem&& !mem_cgroup_is_root(from)&& >> + res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) { >> + printk(KERN_WARNING "Can't move tasks between cgroups: " >> + "Kernel memory held. task: %s\n", p->comm); >> + return 1; >> + } >> +#endif > > Hmm, the kernel memory is not guaranteed as being held by the 'task' ? > > How about > "Now, moving task between cgroup is disallowed while the source cgroup > containes kmem reference." ? > > Hmm.. we need to fix this task-move/rmdir issue before production use. > > > Thanks, > -Kame > Hi Kame, Let me tell you the direction I am going wrt task movement: The only reasons I haven't included so far, is that I believe it needs more testing, and as you know, I am right now more interested in getting past the initial barriers for inclusion. I am committed to fix anything that needs to be fixed - stylish or non-stylish before we remove the experimental flag. So what I intend to do, is to basically * lock the task, * scan through its file descriptors list, * identify which of them are sockets, * cast them to struct sock *, * see if it has a cgrp associated * see if cgrp == from At this point we can decrement sockets allocated by 1 in from, and memory_allocated by sk_forward_alloc (increasing by equal quantities in the destination cgroup) I belive it will work. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2df5d3c..ab7e57b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5451,10 +5451,19 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, { int ret = 0; struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); + struct mem_cgroup *from = mem_cgroup_from_task(p); + +#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_INET) + if (from != mem && !mem_cgroup_is_root(from) && + res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) { + printk(KERN_WARNING "Can't move tasks between cgroups: " + "Kernel memory held. task: %s\n", p->comm); + return 1; + } +#endif if (mem->move_charge_at_immigrate) { struct mm_struct *mm; - struct mem_cgroup *from = mem_cgroup_from_task(p); VM_BUG_ON(from == mem); @@ -5622,6 +5631,18 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgroup, struct task_struct *p) { + struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); + struct mem_cgroup *from = mem_cgroup_from_task(p); + +#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_INET) + if (from != mem && !mem_cgroup_is_root(from) && + res_counter_read_u64(&from->tcp_mem.tcp_memory_allocated, RES_USAGE)) { + printk(KERN_WARNING "Can't move tasks between cgroups: " + "Kernel memory held. task: %s\n", p->comm); + return 1; + } +#endif + return 0; } static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
Since this code is still experimental, we are leaving the exact details of how to move tasks between cgroups when kernel memory accounting is used as future work. For now, we simply disallow movement if there are any pending accounted memory. Signed-off-by: Glauber Costa <glommer@parallels.com> CC: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com> --- mm/memcontrol.c | 23 ++++++++++++++++++++++- 1 files changed, 22 insertions(+), 1 deletions(-)