Re: [RFC][-mm PATCH 6/8] Memory controller add per container LRU and reclaim (v3)
YAMAMOTO Takashi wrote:
> hi,
>
>> +unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
>> +struct list_head *dst,
>> +unsigned long *scanned, int order,
>> +int mode, struct zone *z,
>> +struct mem_container *mem_cont,
>> +int active)
>> +{
>> +unsigned long nr_taken = 0;
>> +struct page *page;
>> +unsigned long scan;
>> +LIST_HEAD(mp_list);
>> +struct list_head *src;
>> +struct meta_page *mp;
>> +
>> +if (active)
>> +src = _cont->active_list;
>> +else
>> +src = _cont->inactive_list;
>> +
>> +for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
>> +mp = list_entry(src->prev, struct meta_page, lru);
>> +page = mp->page;
>> +
>
> - is it safe to pick the lists without mem_cont->lru_lock held?
>
> - what prevents mem_container_uncharge from freeing this meta_page
> behind us?
>
> YAMAMOTO Takashi
Hi, YAMAMOTO,
We do take the lru_lock before deleting the page from the list
and in mem_container_move_lists(). But, I guess like you point
out page = mp->page might not be a safe operation. I'll fix
the problem in the next release.
Thanks for the review,
--
Balbir Singh
Linux Technology Center
IBM, ISTL
-
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Re: [RFC][-mm PATCH 6/8] Memory controller add per container LRU and reclaim (v3)
hi,
> +unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
> + struct list_head *dst,
> + unsigned long *scanned, int order,
> + int mode, struct zone *z,
> + struct mem_container *mem_cont,
> + int active)
> +{
> + unsigned long nr_taken = 0;
> + struct page *page;
> + unsigned long scan;
> + LIST_HEAD(mp_list);
> + struct list_head *src;
> + struct meta_page *mp;
> +
> + if (active)
> + src = _cont->active_list;
> + else
> + src = _cont->inactive_list;
> +
> + for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
> + mp = list_entry(src->prev, struct meta_page, lru);
> + page = mp->page;
> +
- is it safe to pick the lists without mem_cont->lru_lock held?
- what prevents mem_container_uncharge from freeing this meta_page
behind us?
YAMAMOTO Takashi
-
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: [RFC][-mm PATCH 6/8] Memory controller add per container LRU and reclaim (v3)
hi,
+unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
+ struct list_head *dst,
+ unsigned long *scanned, int order,
+ int mode, struct zone *z,
+ struct mem_container *mem_cont,
+ int active)
+{
+ unsigned long nr_taken = 0;
+ struct page *page;
+ unsigned long scan;
+ LIST_HEAD(mp_list);
+ struct list_head *src;
+ struct meta_page *mp;
+
+ if (active)
+ src = mem_cont-active_list;
+ else
+ src = mem_cont-inactive_list;
+
+ for (scan = 0; scan nr_to_scan !list_empty(src); scan++) {
+ mp = list_entry(src-prev, struct meta_page, lru);
+ page = mp-page;
+
- is it safe to pick the lists without mem_cont-lru_lock held?
- what prevents mem_container_uncharge from freeing this meta_page
behind us?
YAMAMOTO Takashi
-
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: [RFC][-mm PATCH 6/8] Memory controller add per container LRU and reclaim (v3)
YAMAMOTO Takashi wrote:
hi,
+unsigned long mem_container_isolate_pages(unsigned long nr_to_scan,
+struct list_head *dst,
+unsigned long *scanned, int order,
+int mode, struct zone *z,
+struct mem_container *mem_cont,
+int active)
+{
+unsigned long nr_taken = 0;
+struct page *page;
+unsigned long scan;
+LIST_HEAD(mp_list);
+struct list_head *src;
+struct meta_page *mp;
+
+if (active)
+src = mem_cont-active_list;
+else
+src = mem_cont-inactive_list;
+
+for (scan = 0; scan nr_to_scan !list_empty(src); scan++) {
+mp = list_entry(src-prev, struct meta_page, lru);
+page = mp-page;
+
- is it safe to pick the lists without mem_cont-lru_lock held?
- what prevents mem_container_uncharge from freeing this meta_page
behind us?
YAMAMOTO Takashi
Hi, YAMAMOTO,
We do take the lru_lock before deleting the page from the list
and in mem_container_move_lists(). But, I guess like you point
out page = mp-page might not be a safe operation. I'll fix
the problem in the next release.
Thanks for the review,
--
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 [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
