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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Hugh Dickins <hughd@google.com>,
	William Kucharski <william.kucharski@oracle.com>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	Matthew Auld <matthew.auld@intel.com>,
	Huang Ying <ying.huang@intel.com>,
	intel-gfx@lists.freedesktop.org, cgroups@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/8] proc: Optimise smaps for shmem entries
Date: Thu, 10 Sep 2020 19:33:14 +0100
Message-ID: <20200910183318.20139-5-willy@infradead.org> (raw)
In-Reply-To: <20200910183318.20139-1-willy@infradead.org>

Avoid bumping the refcount on pages when we're only interested in the
swap entries.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 fs/proc/task_mmu.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5066b0251ed8..e42d9e5e9a3c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -520,16 +520,10 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 			page = device_private_entry_to_page(swpent);
 	} else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap
 							&& pte_none(*pte))) {
-		page = find_get_entry(vma->vm_file->f_mapping,
+		page = xa_load(&vma->vm_file->f_mapping->i_pages,
 						linear_page_index(vma, addr));
-		if (!page)
-			return;
-
 		if (xa_is_value(page))
 			mss->swap += PAGE_SIZE;
-		else
-			put_page(page);
-
 		return;
 	}
 
-- 
2.28.0



  parent reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-10 18:33 [PATCH v2 0/8] Return head pages from find_*_entry Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 1/8] mm: Factor find_get_incore_page out of mincore_page Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 2/8] mm: Use find_get_incore_page in memcontrol Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 3/8] mm: Optimise madvise WILLNEED Matthew Wilcox (Oracle)
2020-09-14 16:17   ` Qian Cai
2020-09-14 16:47     ` Qian Cai
2020-09-14 16:50     ` Matthew Wilcox
2020-09-14 19:44       ` Qian Cai
2020-09-10 18:33 ` Matthew Wilcox (Oracle) [this message]
2020-09-10 18:33 ` [PATCH v2 5/8] i915: Use find_lock_page instead of find_lock_entry Matthew Wilcox (Oracle)
2020-09-10 18:33 ` [PATCH v2 6/8] mm: Convert find_get_entry to return the head page Matthew Wilcox (Oracle)
2020-09-14  8:55   ` [mm] 2037ab69a5: BUG:KASAN:null-ptr-deref_in_t kernel test robot
2020-09-14 11:27     ` Matthew Wilcox
2020-09-10 18:33 ` [PATCH v2 7/8] mm/shmem: Return head page from find_lock_entry Matthew Wilcox (Oracle)
2020-09-12  3:20   ` Matthew Wilcox
2020-09-10 18:33 ` [PATCH v2 8/8] mm: Add find_lock_head Matthew Wilcox (Oracle)
2020-09-15  8:10 ` [PATCH v2 0/8] Return head pages from find_*_entry Hugh Dickins
2020-09-15 12:53   ` Naresh Kamboju
2020-09-15 13:08     ` Matthew Wilcox

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