[SPARC64]: Don't kill the page allocator when growing a TSB. (b52439c2) · Commits · 戴 / test

arch/sparc64/mm/tsb.c

+35 −8

Original line number	Diff line number	Diff line
		@@ -216,7 +216,8 @@ static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_bytes)
		*
		* The TSB can be anywhere from 8K to 1MB in size, in increasing powers
		* of two. The TSB must be aligned to it's size, so f.e. a 512K TSB
		* must be 512K aligned.
		* must be 512K aligned. It also must be physically contiguous, so we
		* cannot use vmalloc().
		*
		* The idea here is to grow the TSB when the RSS of the process approaches
		* the number of entries that the current TSB can hold at once. Currently,
		@@ -228,6 +229,8 @@ void tsb_grow(struct mm_struct *mm, unsigned long rss)
		unsigned long size, old_size, flags;
		struct page *page;
		struct tsb old_tsb, new_tsb;
		unsigned long order, new_rss_limit;
		gfp_t gfp_flags;

		if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
		max_tsb_size = (PAGE_SIZE << MAX_ORDER);
		@@ -240,9 +243,37 @@ void tsb_grow(struct mm_struct *mm, unsigned long rss)
		break;
		}

		page = alloc_pages(GFP_KERNEL, get_order(size));
		if (unlikely(!page))
		if (size == max_tsb_size)
		new_rss_limit = ~0UL;
		else
		new_rss_limit = ((size / sizeof(struct tsb)) * 3) / 4;

		retry_page_alloc:
		order = get_order(size);
		gfp_flags = GFP_KERNEL;
		if (order > 1)
		gfp_flags = __GFP_NOWARN \| __GFP_NORETRY;

		page = alloc_pages(gfp_flags, order);
		if (unlikely(!page)) {
		/* Not being able to fork due to a high-order TSB
		* allocation failure is very bad behavior. Just back
		* down to a 0-order allocation and force no TSB
		* growing for this address space.
		*/
		if (mm->context.tsb == NULL && order > 0) {
		size = PAGE_SIZE;
		new_rss_limit = ~0UL;
		goto retry_page_alloc;
		}

		/* If we failed on a TSB grow, we are under serious
		* memory pressure so don't try to grow any more.
		*/
		if (mm->context.tsb != NULL)
		mm->context.tsb_rss_limit = ~0UL;
		return;
		}

		/* Mark all tags as invalid. */
		new_tsb = page_address(page);
		@@ -286,11 +317,7 @@ void tsb_grow(struct mm_struct *mm, unsigned long rss)
		return;
		}

		if (size == max_tsb_size)
		mm->context.tsb_rss_limit = ~0UL;
		else
		mm->context.tsb_rss_limit =
		((size / sizeof(struct tsb)) * 3) / 4;
		mm->context.tsb_rss_limit = new_rss_limit;

		if (old_tsb) {
		extern void copy_tsb(unsigned long old_tsb_base,

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