Re: [-mm][PATCH 4/4] Add memrlimit controller accounting andcontrol (v4)
From: Balbir Singh
Date: Sat May 17 2008 - 16:18:52 EST
* Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> [2008-05-18 01:45:45]:
> * Paul Menage <menage@xxxxxxxxxx> [2008-05-15 08:28:46]:
>
> > On Thu, May 15, 2008 at 1:25 AM, Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > But the only *new* cases of taking the mmap_sem that this would
> > > > introduce would be:
> > > >
> > > > - on a failed vm limit charge
> > >
> > > Why a failed charge? Aren't we talking of moving all charge/uncharge
> > > under mmap_sem?
> > >
> >
> > Sorry, I worded that wrongly - I meant "cleaning up a successful
> > charge after an expansion fails for other reasons"
> >
> > I thought that all the charges and most of the uncharges were already
> > under mmap_sem, and it would just be a few of the cleanup paths that
> > needed to take it.
> >
> > >
> > > > - when a task moves between two cgroups in the memrlimit hierarchy.
> > > >
> > >
> > > Yes, this would nest cgroup_mutex and mmap_sem. Not sure if that would
> > > be a bad side-effect.
> > >
> >
> > I think it's already nested that way - e.g. the cpusets code can call
> > various migration functions (which take mmap_sem) while holding
> > cgroup_mutex.
> >
> > >
> > > Refactor the code to try and use mmap_sem and see what I come up
> > > with. Basically use mmap_sem for all charge/uncharge operations as
> > > well use mmap_sem in read_mode in the move_task() and
> > > mm_owner_changed() callbacks. That should take care of the race
> > > conditions discussed, unless I missed something.
> >
> > Sounds good.
> >
> > Thanks,
> >
> I've revamped the last two patches. Please review
>
Here's the last patch for review
This patch adds support for accounting and control of virtual address space
limits. The accounting is done via the rlimit_cgroup_(un)charge_as functions.
The core of the accounting takes place during fork time in copy_process(),
may_expand_vm(), remove_vma_list() and exit_mmap().
Changelog v5->v4
Move specific hooks in code to insert_vm_struct
Use mmap_sem to protect mm->owner from changing and mm->owner from
changing cgroups.
Signed-off-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/ptrace.c | 18 +++++--
include/linux/memrlimitcgroup.h | 21 +++++++++
kernel/fork.c | 8 +++
mm/memrlimitcgroup.c | 92 ++++++++++++++++++++++++++++++++++++++++
mm/mmap.c | 17 ++++++-
5 files changed, 149 insertions(+), 7 deletions(-)
diff -puN arch/ia64/kernel/perfmon.c~memrlimit-controller-address-space-accounting-and-control arch/ia64/kernel/perfmon.c
diff -puN arch/x86/kernel/ds.c~memrlimit-controller-address-space-accounting-and-control arch/x86/kernel/ds.c
diff -puN fs/exec.c~memrlimit-controller-address-space-accounting-and-control fs/exec.c
diff -puN include/linux/memrlimitcgroup.h~memrlimit-controller-address-space-accounting-and-control include/linux/memrlimitcgroup.h
--- linux-2.6.26-rc2/include/linux/memrlimitcgroup.h~memrlimit-controller-address-space-accounting-and-control 2008-05-17 23:14:53.000000000 +0530
+++ linux-2.6.26-rc2-balbir/include/linux/memrlimitcgroup.h 2008-05-17 23:14:53.000000000 +0530
@@ -16,4 +16,25 @@
#ifndef LINUX_MEMRLIMITCGROUP_H
#define LINUX_MEMRLIMITCGROUP_H
+#ifdef CONFIG_CGROUP_MEMRLIMIT_CTLR
+
+int memrlimit_cgroup_charge_as(struct mm_struct *mm, unsigned long nr_pages);
+void memrlimit_cgroup_uncharge_as(struct mm_struct *mm, unsigned long nr_pages);
+
+#else /* !CONFIG_CGROUP_RLIMIT_CTLR */
+
+static inline int
+memrlimit_cgroup_charge_as(struct mm_struct *mm, unsigned long nr_pages)
+{
+ return 0;
+}
+
+static inline void
+memrlimit_cgroup_uncharge_as(struct mm_struct *mm, unsigned long nr_pages)
+{
+}
+
+#endif /* CONFIG_CGROUP_RLIMIT_CTLR */
+
+
#endif /* LINUX_MEMRLIMITCGROUP_H */
diff -puN kernel/fork.c~memrlimit-controller-address-space-accounting-and-control kernel/fork.c
--- linux-2.6.26-rc2/kernel/fork.c~memrlimit-controller-address-space-accounting-and-control 2008-05-17 23:14:53.000000000 +0530
+++ linux-2.6.26-rc2-balbir/kernel/fork.c 2008-05-17 23:15:55.000000000 +0530
@@ -54,6 +54,7 @@
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
+#include <linux/memrlimitcgroup.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -267,6 +268,7 @@ static int dup_mmap(struct mm_struct *mm
mm->total_vm -= pages;
vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
-pages);
+ memrlimit_cgroup_uncharge_as(mm, pages);
continue;
}
charge = 0;
@@ -596,6 +598,12 @@ static int copy_mm(unsigned long clone_f
atomic_inc(&oldmm->mm_users);
mm = oldmm;
goto good_mm;
+ } else {
+ down_write(&oldmm->mmap_sem);
+ retval = memrlimit_cgroup_charge_as(oldmm, oldmm->total_vm);
+ up_write(&oldmm->mmap_sem);
+ if (retval)
+ goto fail_nomem;
}
retval = -ENOMEM;
diff -puN mm/memrlimitcgroup.c~memrlimit-controller-address-space-accounting-and-control mm/memrlimitcgroup.c
--- linux-2.6.26-rc2/mm/memrlimitcgroup.c~memrlimit-controller-address-space-accounting-and-control 2008-05-17 23:14:53.000000000 +0530
+++ linux-2.6.26-rc2-balbir/mm/memrlimitcgroup.c 2008-05-18 00:47:31.000000000 +0530
@@ -45,6 +45,38 @@ static struct memrlimit_cgroup *memrlimi
struct memrlimit_cgroup, css);
}
+static struct memrlimit_cgroup *
+memrlimit_cgroup_from_task(struct task_struct *p)
+{
+ return container_of(task_subsys_state(p, memrlimit_cgroup_subsys_id),
+ struct memrlimit_cgroup, css);
+}
+
+/*
+ * Charge the cgroup for address space usage - mmap(), malloc() (through
+ * brk(), sbrk()), stack expansion, mremap(), etc - called with
+ * mmap_sem held.
+ */
+int memrlimit_cgroup_charge_as(struct mm_struct *mm, unsigned long nr_pages)
+{
+ struct memrlimit_cgroup *memrcg;
+
+ memrcg = memrlimit_cgroup_from_task(mm->owner);
+ return res_counter_charge(&memrcg->as_res, (nr_pages << PAGE_SHIFT));
+}
+
+/*
+ * Uncharge the cgroup, as the address space of one of the tasks is
+ * decreasing - called with mmap_sem held.
+ */
+void memrlimit_cgroup_uncharge_as(struct mm_struct *mm, unsigned long nr_pages)
+{
+ struct memrlimit_cgroup *memrcg;
+
+ memrcg = memrlimit_cgroup_from_task(mm->owner);
+ res_counter_uncharge(&memrcg->as_res, (nr_pages << PAGE_SHIFT));
+}
+
static struct cgroup_subsys_state *
memrlimit_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
@@ -134,11 +166,71 @@ static int memrlimit_cgroup_populate(str
ARRAY_SIZE(memrlimit_cgroup_files));
}
+static void memrlimit_cgroup_move_task(struct cgroup_subsys *ss,
+ struct cgroup *cgrp,
+ struct cgroup *old_cgrp,
+ struct task_struct *p)
+{
+ struct mm_struct *mm;
+ struct memrlimit_cgroup *memrcg, *old_memrcg;
+
+ mm = get_task_mm(p);
+ if (mm == NULL)
+ return;
+
+ /*
+ * Hold mmap_sem, so that total_vm does not change underneath us
+ */
+ down_read(&mm->mmap_sem);
+
+ rcu_read_lock();
+ if (p != rcu_dereference(mm->owner))
+ goto out;
+
+ memrcg = memrlimit_cgroup_from_cgrp(cgrp);
+ old_memrcg = memrlimit_cgroup_from_cgrp(old_cgrp);
+
+ if (memrcg == old_memrcg)
+ goto out;
+
+ if (res_counter_charge(&memrcg->as_res, (mm->total_vm << PAGE_SHIFT)))
+ goto out;
+ res_counter_uncharge(&old_memrcg->as_res, (mm->total_vm << PAGE_SHIFT));
+out:
+ rcu_read_unlock();
+ up_read(&mm->mmap_sem);
+ mmput(mm);
+}
+
+/*
+ * This callback is called with mmap_sem held
+ */
+static void memrlimit_cgroup_mm_owner_changed(struct cgroup_subsys *ss,
+ struct cgroup *cgrp,
+ struct cgroup *old_cgrp,
+ struct task_struct *p)
+{
+ struct memrlimit_cgroup *memrcg, *old_memrcg;
+ struct mm_struct *mm = get_task_mm(p);
+
+ BUG_ON(!mm);
+ memrcg = memrlimit_cgroup_from_cgrp(cgrp);
+ old_memrcg = memrlimit_cgroup_from_cgrp(old_cgrp);
+
+ if (res_counter_charge(&memrcg->as_res, (mm->total_vm << PAGE_SHIFT)))
+ goto out;
+ res_counter_uncharge(&old_memrcg->as_res, (mm->total_vm << PAGE_SHIFT));
+out:
+ mmput(mm);
+}
+
struct cgroup_subsys memrlimit_cgroup_subsys = {
.name = "memrlimit",
.subsys_id = memrlimit_cgroup_subsys_id,
.create = memrlimit_cgroup_create,
.destroy = memrlimit_cgroup_destroy,
.populate = memrlimit_cgroup_populate,
+ .attach = memrlimit_cgroup_move_task,
+ .mm_owner_changed = memrlimit_cgroup_mm_owner_changed,
.early_init = 0,
};
diff -puN mm/mmap.c~memrlimit-controller-address-space-accounting-and-control mm/mmap.c
--- linux-2.6.26-rc2/mm/mmap.c~memrlimit-controller-address-space-accounting-and-control 2008-05-17 23:14:53.000000000 +0530
+++ linux-2.6.26-rc2-balbir/mm/mmap.c 2008-05-17 23:14:53.000000000 +0530
@@ -26,6 +26,7 @@
#include <linux/mount.h>
#include <linux/mempolicy.h>
#include <linux/rmap.h>
+#include <linux/memrlimitcgroup.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -1730,6 +1731,7 @@ static void remove_vma_list(struct mm_st
long nrpages = vma_pages(vma);
mm->total_vm -= nrpages;
+ memrlimit_cgroup_uncharge_as(mm, nrpages);
if (vma->vm_flags & VM_LOCKED)
mm->locked_vm -= nrpages;
vm_stat_account(mm, vma->vm_flags, vma->vm_file, -nrpages);
@@ -2056,6 +2058,7 @@ void exit_mmap(struct mm_struct *mm)
/* Use -1 here to ensure all VMAs in the mm are unmapped */
end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
vm_unacct_memory(nr_accounted);
+ memrlimit_cgroup_uncharge_as(mm, mm->total_vm);
free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
tlb_finish_mmu(tlb, 0, end);
@@ -2078,6 +2081,9 @@ int insert_vm_struct(struct mm_struct *
struct vm_area_struct * __vma, * prev;
struct rb_node ** rb_link, * rb_parent;
+ if (memrlimit_cgroup_charge_as(mm, vma_pages(vma)))
+ return -ENOMEM;
+
/*
* The vm_pgoff of a purely anonymous vma should be irrelevant
* until its first write fault, when page's anon_vma and index
@@ -2096,12 +2102,15 @@ int insert_vm_struct(struct mm_struct *
}
__vma = find_vma_prepare(mm,vma->vm_start,&prev,&rb_link,&rb_parent);
if (__vma && __vma->vm_start < vma->vm_end)
- return -ENOMEM;
+ goto err;
if ((vma->vm_flags & VM_ACCOUNT) &&
security_vm_enough_memory_mm(mm, vma_pages(vma)))
- return -ENOMEM;
+ goto err;
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
+err:
+ memrlimit_cgroup_uncharge_as(mm, vma_pages(vma));
+ return -ENOMEM;
}
/*
@@ -2174,6 +2183,10 @@ int may_expand_vm(struct mm_struct *mm,
if (cur + npages > lim)
return 0;
+
+ if (memrlimit_cgroup_charge_as(mm, npages))
+ return 0;
+
return 1;
}
diff -puN arch/x86/kernel/ptrace.c~memrlimit-controller-address-space-accounting-and-control arch/x86/kernel/ptrace.c
--- linux-2.6.26-rc2/arch/x86/kernel/ptrace.c~memrlimit-controller-address-space-accounting-and-control 2008-05-17 23:14:53.000000000 +0530
+++ linux-2.6.26-rc2-balbir/arch/x86/kernel/ptrace.c 2008-05-17 23:14:53.000000000 +0530
@@ -20,6 +20,7 @@
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/signal.h>
+#include <linux/memrlimitcgroup.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
@@ -782,21 +783,25 @@ static int ptrace_bts_realloc(struct tas
current->mm->total_vm -= old_size;
current->mm->locked_vm -= old_size;
+ memrlimit_cgroup_uncharge_as(mm, old_size);
if (size == 0)
goto out;
+ if (memrlimit_cgroup_charge_as(current->mm, size))
+ goto out;
+
rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
vm = current->mm->total_vm + size;
if (rlim < vm) {
ret = -ENOMEM;
if (!reduce_size)
- goto out;
+ goto out_uncharge;
size = rlim - current->mm->total_vm;
if (size <= 0)
- goto out;
+ goto out_uncharge;
}
rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
@@ -805,21 +810,24 @@ static int ptrace_bts_realloc(struct tas
ret = -ENOMEM;
if (!reduce_size)
- goto out;
+ goto out_uncharge;
size = rlim - current->mm->locked_vm;
if (size <= 0)
- goto out;
+ goto out_uncharge;
}
ret = ds_allocate((void **)&child->thread.ds_area_msr,
size << PAGE_SHIFT);
if (ret < 0)
- goto out;
+ goto out_uncharge;
current->mm->total_vm += size;
current->mm->locked_vm += size;
+out_uncharge:
+ if (ret < 0)
+ memrlimit_cgroup_uncharge_as(mm, size);
out:
if (child->thread.ds_area_msr)
set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
_
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/