Messages in this thread Patch in this message | | | Date | Sun, 18 May 2008 01:47:55 +0530 | From | Balbir Singh <> | Subject | Re: [-mm][PATCH 4/4] Add memrlimit controller accounting and control (v4) |
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* Balbir Singh <balbir@linux.vnet.ibm.com> [2008-05-18 01:45:45]:
> * Paul Menage <menage@google.com> [2008-05-15 08:28:46]: > > > On Thu, May 15, 2008 at 1:25 AM, Balbir Singh <balbir@linux.vnet.ibm.com> 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@linux.vnet.ibm.com> ---
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
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