Commit c8bd84f7 authored by zhenwei pi's avatar zhenwei pi Committed by Andrew Morton
Browse files

mm/memory-failure.c: simplify num_poisoned_pages_dec 

Don't decrease the number of poisoned pages in page_alloc.c, let the
memory-failure.c do inc/dec poisoned pages only.

Also simplify unpoison_memory(), only decrease the number of
poisoned pages when:
 - TestClearPageHWPoison() succeed
 - put_page_back_buddy succeed

After decreasing, print necessary log.

Finally, remove clear_page_hwpoison() and unpoison_taken_off_page().

Link: https://lkml.kernel.org/r/20220509105641.491313-3-pizhenwei@bytedance.com


Signed-off-by: default avatarzhenwei pi <pizhenwei@bytedance.com>
Acked-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 60f272f6

mm/memory-failure.c

+9 −28
Original line number Diff line number Diff line
@@ -2092,28 +2092,6 @@ core_initcall(memory_failure_init); 
		pr_info(fmt, pfn);			\

})



static inline int clear_page_hwpoison(struct ratelimit_state *rs, struct page *p)

{

	if (TestClearPageHWPoison(p)) {

		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",

				 page_to_pfn(p), rs);

		num_poisoned_pages_dec();

		return 1;

	}

	return 0;

}



static inline int unpoison_taken_off_page(struct ratelimit_state *rs,

					  struct page *p)

{

	if (put_page_back_buddy(p)) {

		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",

				 page_to_pfn(p), rs);

		return 0;

	}

	return -EBUSY;

}



/**

 * unpoison_memory - Unpoison a previously poisoned page

 * @pfn: Page number of the to be unpoisoned page
@@ -2131,6 +2109,7 @@ int unpoison_memory(unsigned long pfn) 
	struct page *page;

	struct page *p;

	int ret = -EBUSY;

	int freeit = 0;

	static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,

					DEFAULT_RATELIMIT_BURST);
@@ -2171,18 +2150,15 @@ int unpoison_memory(unsigned long pfn) 


	ret = get_hwpoison_page(p, MF_UNPOISON);

	if (!ret) {

		if (clear_page_hwpoison(&unpoison_rs, page))

			ret = 0;

		else

			ret = -EBUSY;

		ret = TestClearPageHWPoison(page) ? 0 : -EBUSY;

	} else if (ret < 0) {

		if (ret == -EHWPOISON) {

			ret = unpoison_taken_off_page(&unpoison_rs, p);

			ret = put_page_back_buddy(p) ? 0 : -EBUSY;

		} else

			unpoison_pr_info("Unpoison: failed to grab page %#lx\n",

					 pfn, &unpoison_rs);

	} else {

		int freeit = clear_page_hwpoison(&unpoison_rs, p);

		freeit = !!TestClearPageHWPoison(p);



		put_page(page);

		if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1)) {
@@ -2193,6 +2169,11 @@ int unpoison_memory(unsigned long pfn) 


unlock_mutex:

	mutex_unlock(&mf_mutex);

	if (!ret || freeit) {

		num_poisoned_pages_dec();

		unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",

				 page_to_pfn(p), &unpoison_rs);

	}

	return ret;

}

EXPORT_SYMBOL(unpoison_memory);

mm/page_alloc.c

+0 −1
Original line number Diff line number Diff line
@@ -9497,7 +9497,6 @@ bool put_page_back_buddy(struct page *page) 
		ClearPageHWPoisonTakenOff(page);

		__free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE);

		if (TestClearPageHWPoison(page)) {

			num_poisoned_pages_dec();

			ret = true;

		}

	}