memcg: sanitize __mem_cgroup_try_charge() call protocol
Some callsites pass a memcg directly, some callsites pass an mm that then has to be translated to a memcg. This makes for a terrible function interface. Just push the mm-to-memcg translation into the respective callsites and always pass a memcg to mem_cgroup_try_charge(). [mhocko@suse.cz: add charge mm helper] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
b6b6cc72bc
commit
6d1fdc4893
195
mm/memcontrol.c
195
mm/memcontrol.c
|
@ -2575,7 +2575,7 @@ static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
|
|||
}
|
||||
|
||||
|
||||
/* See __mem_cgroup_try_charge() for details */
|
||||
/* See mem_cgroup_try_charge() for details */
|
||||
enum {
|
||||
CHARGE_OK, /* success */
|
||||
CHARGE_RETRY, /* need to retry but retry is not bad */
|
||||
|
@ -2648,45 +2648,34 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|||
return CHARGE_NOMEM;
|
||||
}
|
||||
|
||||
/*
|
||||
* __mem_cgroup_try_charge() does
|
||||
* 1. detect memcg to be charged against from passed *mm and *ptr,
|
||||
* 2. update res_counter
|
||||
* 3. call memory reclaim if necessary.
|
||||
/**
|
||||
* mem_cgroup_try_charge - try charging a memcg
|
||||
* @memcg: memcg to charge
|
||||
* @nr_pages: number of pages to charge
|
||||
* @oom: trigger OOM if reclaim fails
|
||||
*
|
||||
* In some special case, if the task is fatal, fatal_signal_pending() or
|
||||
* has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
|
||||
* to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
|
||||
* as possible without any hazards. 2: all pages should have a valid
|
||||
* pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
|
||||
* pointer, that is treated as a charge to root_mem_cgroup.
|
||||
*
|
||||
* So __mem_cgroup_try_charge() will return
|
||||
* 0 ... on success, filling *ptr with a valid memcg pointer.
|
||||
* -ENOMEM ... charge failure because of resource limits.
|
||||
* -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
|
||||
*
|
||||
* Unlike the exported interface, an "oom" parameter is added. if oom==true,
|
||||
* the oom-killer can be invoked.
|
||||
* Returns 0 if @memcg was charged successfully, -EINTR if the charge
|
||||
* was bypassed to root_mem_cgroup, and -ENOMEM if the charge failed.
|
||||
*/
|
||||
static int __mem_cgroup_try_charge(struct mm_struct *mm,
|
||||
static int mem_cgroup_try_charge(struct mem_cgroup *memcg,
|
||||
gfp_t gfp_mask,
|
||||
unsigned int nr_pages,
|
||||
struct mem_cgroup **ptr,
|
||||
bool oom)
|
||||
{
|
||||
unsigned int batch = max(CHARGE_BATCH, nr_pages);
|
||||
int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
||||
struct mem_cgroup *memcg = NULL;
|
||||
int ret;
|
||||
|
||||
if (mem_cgroup_is_root(memcg))
|
||||
goto done;
|
||||
/*
|
||||
* Unlike gloval-vm's OOM-kill, we're not in memory shortage
|
||||
* in system level. So, allow to go ahead dying process in addition to
|
||||
* MEMDIE process.
|
||||
* Unlike in global OOM situations, memcg is not in a physical
|
||||
* memory shortage. Allow dying and OOM-killed tasks to
|
||||
* bypass the last charges so that they can exit quickly and
|
||||
* free their memory.
|
||||
*/
|
||||
if (unlikely(test_thread_flag(TIF_MEMDIE)
|
||||
|| fatal_signal_pending(current)))
|
||||
if (unlikely(test_thread_flag(TIF_MEMDIE) ||
|
||||
fatal_signal_pending(current)))
|
||||
goto bypass;
|
||||
|
||||
if (unlikely(task_in_memcg_oom(current)))
|
||||
|
@ -2695,14 +2684,6 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
|
|||
if (gfp_mask & __GFP_NOFAIL)
|
||||
oom = false;
|
||||
again:
|
||||
if (*ptr) { /* css should be a valid one */
|
||||
memcg = *ptr;
|
||||
css_get(&memcg->css);
|
||||
} else {
|
||||
memcg = get_mem_cgroup_from_mm(mm);
|
||||
}
|
||||
if (mem_cgroup_is_root(memcg))
|
||||
goto done;
|
||||
if (consume_stock(memcg, nr_pages))
|
||||
goto done;
|
||||
|
||||
|
@ -2710,10 +2691,8 @@ again:
|
|||
bool invoke_oom = oom && !nr_oom_retries;
|
||||
|
||||
/* If killed, bypass charge */
|
||||
if (fatal_signal_pending(current)) {
|
||||
css_put(&memcg->css);
|
||||
if (fatal_signal_pending(current))
|
||||
goto bypass;
|
||||
}
|
||||
|
||||
ret = mem_cgroup_do_charge(memcg, gfp_mask, batch,
|
||||
nr_pages, invoke_oom);
|
||||
|
@ -2722,17 +2701,12 @@ again:
|
|||
break;
|
||||
case CHARGE_RETRY: /* not in OOM situation but retry */
|
||||
batch = nr_pages;
|
||||
css_put(&memcg->css);
|
||||
memcg = NULL;
|
||||
goto again;
|
||||
case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
|
||||
css_put(&memcg->css);
|
||||
goto nomem;
|
||||
case CHARGE_NOMEM: /* OOM routine works */
|
||||
if (!oom || invoke_oom) {
|
||||
css_put(&memcg->css);
|
||||
if (!oom || invoke_oom)
|
||||
goto nomem;
|
||||
}
|
||||
nr_oom_retries--;
|
||||
break;
|
||||
}
|
||||
|
@ -2741,19 +2715,43 @@ again:
|
|||
if (batch > nr_pages)
|
||||
refill_stock(memcg, batch - nr_pages);
|
||||
done:
|
||||
css_put(&memcg->css);
|
||||
*ptr = memcg;
|
||||
return 0;
|
||||
nomem:
|
||||
if (!(gfp_mask & __GFP_NOFAIL)) {
|
||||
*ptr = NULL;
|
||||
if (!(gfp_mask & __GFP_NOFAIL))
|
||||
return -ENOMEM;
|
||||
}
|
||||
bypass:
|
||||
*ptr = root_mem_cgroup;
|
||||
return -EINTR;
|
||||
}
|
||||
|
||||
/**
|
||||
* mem_cgroup_try_charge_mm - try charging a mm
|
||||
* @mm: mm_struct to charge
|
||||
* @nr_pages: number of pages to charge
|
||||
* @oom: trigger OOM if reclaim fails
|
||||
*
|
||||
* Returns the charged mem_cgroup associated with the given mm_struct or
|
||||
* NULL the charge failed.
|
||||
*/
|
||||
static struct mem_cgroup *mem_cgroup_try_charge_mm(struct mm_struct *mm,
|
||||
gfp_t gfp_mask,
|
||||
unsigned int nr_pages,
|
||||
bool oom)
|
||||
|
||||
{
|
||||
struct mem_cgroup *memcg;
|
||||
int ret;
|
||||
|
||||
memcg = get_mem_cgroup_from_mm(mm);
|
||||
ret = mem_cgroup_try_charge(memcg, gfp_mask, nr_pages, oom);
|
||||
css_put(&memcg->css);
|
||||
if (ret == -EINTR)
|
||||
memcg = root_mem_cgroup;
|
||||
else if (ret)
|
||||
memcg = NULL;
|
||||
|
||||
return memcg;
|
||||
}
|
||||
|
||||
/*
|
||||
* Somemtimes we have to undo a charge we got by try_charge().
|
||||
* This function is for that and do uncharge, put css's refcnt.
|
||||
|
@ -2949,20 +2947,17 @@ static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v)
|
|||
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
|
||||
{
|
||||
struct res_counter *fail_res;
|
||||
struct mem_cgroup *_memcg;
|
||||
int ret = 0;
|
||||
|
||||
ret = res_counter_charge(&memcg->kmem, size, &fail_res);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
_memcg = memcg;
|
||||
ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT,
|
||||
&_memcg, oom_gfp_allowed(gfp));
|
||||
|
||||
ret = mem_cgroup_try_charge(memcg, gfp, size >> PAGE_SHIFT,
|
||||
oom_gfp_allowed(gfp));
|
||||
if (ret == -EINTR) {
|
||||
/*
|
||||
* __mem_cgroup_try_charge() chosed to bypass to root due to
|
||||
* mem_cgroup_try_charge() chosed to bypass to root due to
|
||||
* OOM kill or fatal signal. Since our only options are to
|
||||
* either fail the allocation or charge it to this cgroup, do
|
||||
* it as a temporary condition. But we can't fail. From a
|
||||
|
@ -2972,7 +2967,7 @@ static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
|
|||
*
|
||||
* This condition will only trigger if the task entered
|
||||
* memcg_charge_kmem in a sane state, but was OOM-killed during
|
||||
* __mem_cgroup_try_charge() above. Tasks that were already
|
||||
* mem_cgroup_try_charge() above. Tasks that were already
|
||||
* dying when the allocation triggers should have been already
|
||||
* directed to the root cgroup in memcontrol.h
|
||||
*/
|
||||
|
@ -3826,10 +3821,9 @@ out:
|
|||
int mem_cgroup_newpage_charge(struct page *page,
|
||||
struct mm_struct *mm, gfp_t gfp_mask)
|
||||
{
|
||||
struct mem_cgroup *memcg = NULL;
|
||||
unsigned int nr_pages = 1;
|
||||
struct mem_cgroup *memcg;
|
||||
bool oom = true;
|
||||
int ret;
|
||||
|
||||
if (mem_cgroup_disabled())
|
||||
return 0;
|
||||
|
@ -3848,9 +3842,9 @@ int mem_cgroup_newpage_charge(struct page *page,
|
|||
oom = false;
|
||||
}
|
||||
|
||||
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
|
||||
if (ret == -ENOMEM)
|
||||
return ret;
|
||||
memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, nr_pages, oom);
|
||||
if (!memcg)
|
||||
return -ENOMEM;
|
||||
__mem_cgroup_commit_charge(memcg, page, nr_pages,
|
||||
MEM_CGROUP_CHARGE_TYPE_ANON, false);
|
||||
return 0;
|
||||
|
@ -3867,7 +3861,7 @@ static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
|
|||
gfp_t mask,
|
||||
struct mem_cgroup **memcgp)
|
||||
{
|
||||
struct mem_cgroup *memcg;
|
||||
struct mem_cgroup *memcg = NULL;
|
||||
struct page_cgroup *pc;
|
||||
int ret;
|
||||
|
||||
|
@ -3880,31 +3874,29 @@ static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
|
|||
* in turn serializes uncharging.
|
||||
*/
|
||||
if (PageCgroupUsed(pc))
|
||||
return 0;
|
||||
if (!do_swap_account)
|
||||
goto charge_cur_mm;
|
||||
goto out;
|
||||
if (do_swap_account)
|
||||
memcg = try_get_mem_cgroup_from_page(page);
|
||||
if (!memcg)
|
||||
goto charge_cur_mm;
|
||||
*memcgp = memcg;
|
||||
ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
|
||||
memcg = get_mem_cgroup_from_mm(mm);
|
||||
ret = mem_cgroup_try_charge(memcg, mask, 1, true);
|
||||
css_put(&memcg->css);
|
||||
if (ret == -EINTR)
|
||||
ret = 0;
|
||||
return ret;
|
||||
charge_cur_mm:
|
||||
ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
|
||||
if (ret == -EINTR)
|
||||
ret = 0;
|
||||
memcg = root_mem_cgroup;
|
||||
else if (ret)
|
||||
return ret;
|
||||
out:
|
||||
*memcgp = memcg;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
|
||||
gfp_t gfp_mask, struct mem_cgroup **memcgp)
|
||||
{
|
||||
if (mem_cgroup_disabled()) {
|
||||
*memcgp = NULL;
|
||||
if (mem_cgroup_disabled())
|
||||
return 0;
|
||||
}
|
||||
/*
|
||||
* A racing thread's fault, or swapoff, may have already
|
||||
* updated the pte, and even removed page from swap cache: in
|
||||
|
@ -3912,12 +3904,13 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
|
|||
* there's also a KSM case which does need to charge the page.
|
||||
*/
|
||||
if (!PageSwapCache(page)) {
|
||||
int ret;
|
||||
struct mem_cgroup *memcg;
|
||||
|
||||
ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true);
|
||||
if (ret == -EINTR)
|
||||
ret = 0;
|
||||
return ret;
|
||||
memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
|
||||
if (!memcg)
|
||||
return -ENOMEM;
|
||||
*memcgp = memcg;
|
||||
return 0;
|
||||
}
|
||||
return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
|
||||
}
|
||||
|
@ -3964,8 +3957,8 @@ void mem_cgroup_commit_charge_swapin(struct page *page,
|
|||
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
|
||||
gfp_t gfp_mask)
|
||||
{
|
||||
struct mem_cgroup *memcg = NULL;
|
||||
enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
||||
struct mem_cgroup *memcg;
|
||||
int ret;
|
||||
|
||||
if (mem_cgroup_disabled())
|
||||
|
@ -3973,23 +3966,28 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
|
|||
if (PageCompound(page))
|
||||
return 0;
|
||||
|
||||
if (!PageSwapCache(page)) {
|
||||
/*
|
||||
* Page cache insertions can happen without an actual
|
||||
* task context, e.g. during disk probing on boot.
|
||||
*/
|
||||
if (!mm)
|
||||
memcg = root_mem_cgroup;
|
||||
ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, &memcg, true);
|
||||
if (ret != -ENOMEM)
|
||||
__mem_cgroup_commit_charge(memcg, page, 1, type, false);
|
||||
} else { /* page is swapcache/shmem */
|
||||
if (PageSwapCache(page)) { /* shmem */
|
||||
ret = __mem_cgroup_try_charge_swapin(mm, page,
|
||||
gfp_mask, &memcg);
|
||||
if (!ret)
|
||||
__mem_cgroup_commit_charge_swapin(page, memcg, type);
|
||||
}
|
||||
if (ret)
|
||||
return ret;
|
||||
__mem_cgroup_commit_charge_swapin(page, memcg, type);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Page cache insertions can happen without an actual mm
|
||||
* context, e.g. during disk probing on boot.
|
||||
*/
|
||||
if (unlikely(!mm))
|
||||
memcg = root_mem_cgroup;
|
||||
else {
|
||||
memcg = mem_cgroup_try_charge_mm(mm, gfp_mask, 1, true);
|
||||
if (!memcg)
|
||||
return -ENOMEM;
|
||||
}
|
||||
__mem_cgroup_commit_charge(memcg, page, 1, type, false);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
|
||||
|
@ -6601,8 +6599,7 @@ one_by_one:
|
|||
batch_count = PRECHARGE_COUNT_AT_ONCE;
|
||||
cond_resched();
|
||||
}
|
||||
ret = __mem_cgroup_try_charge(NULL,
|
||||
GFP_KERNEL, 1, &memcg, false);
|
||||
ret = mem_cgroup_try_charge(memcg, GFP_KERNEL, 1, false);
|
||||
if (ret)
|
||||
/* mem_cgroup_clear_mc() will do uncharge later */
|
||||
return ret;
|
||||
|
|
Loading…
Reference in New Issue