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From: Hugh Dickins <hughd@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>, Christoph Lameter <cl@linux.com>,
	Matthew Wilcox <willy@infradead.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	David Hildenbrand <david@redhat.com>,
	Suren Baghdasaryan <surenb@google.com>,
	Yang Shi <shy828301@gmail.com>,
	Sidhartha Kumar <sidhartha.kumar@oracle.com>,
	Vishal Moola <vishal.moola@gmail.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Tejun Heo <tj@kernel.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Michal Hocko <mhocko@suse.com>,
	"Huang, Ying" <ying.huang@intel.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH v2 07/12] mempolicy: mpol_shared_policy_init() without pseudo-vma
Date: Tue, 3 Oct 2023 02:22:59 -0700 (PDT)	[thread overview]
Message-ID: <3bef62d8-ae78-4c2-533-56a44ae425c@google.com> (raw)
In-Reply-To: <ebc0987e-beff-8bfb-9283-234c2cbd17c5@google.com>

mpol_shared_policy_init() does not need to use a pseudo-vma: it can use
sp_alloc() and sp_insert() directly, since the object's shared policy
tree is empty and inaccessible (needing no lock) at get_inode() time.

Signed-off-by: Hugh Dickins <hughd@google.com>
---
 mm/mempolicy.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 1d3f9e1ecbb8..5d99fd5cd60b 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2756,30 +2756,30 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 	rwlock_init(&sp->lock);
 
 	if (mpol) {
-		struct vm_area_struct pvma;
-		struct mempolicy *new;
+		struct sp_node *sn;
+		struct mempolicy *npol;
 		NODEMASK_SCRATCH(scratch);
 
 		if (!scratch)
 			goto put_mpol;
-		/* contextualize the tmpfs mount point mempolicy */
-		new = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
-		if (IS_ERR(new))
+
+		/* contextualize the tmpfs mount point mempolicy to this file */
+		npol = mpol_new(mpol->mode, mpol->flags, &mpol->w.user_nodemask);
+		if (IS_ERR(npol))
 			goto free_scratch; /* no valid nodemask intersection */
 
 		task_lock(current);
-		ret = mpol_set_nodemask(new, &mpol->w.user_nodemask, scratch);
+		ret = mpol_set_nodemask(npol, &mpol->w.user_nodemask, scratch);
 		task_unlock(current);
 		if (ret)
-			goto put_new;
+			goto put_npol;
 
-		/* Create pseudo-vma that contains just the policy */
-		vma_init(&pvma, NULL);
-		pvma.vm_end = TASK_SIZE;	/* policy covers entire file */
-		mpol_set_shared_policy(sp, &pvma, new); /* adds ref */
-
-put_new:
-		mpol_put(new);			/* drop initial ref */
+		/* alloc node covering entire file; adds ref to file's npol */
+		sn = sp_alloc(0, MAX_LFS_FILESIZE >> PAGE_SHIFT, npol);
+		if (sn)
+			sp_insert(sp, sn);
+put_npol:
+		mpol_put(npol);	/* drop initial ref on file's npol */
 free_scratch:
 		NODEMASK_SCRATCH_FREE(scratch);
 put_mpol:
-- 
2.35.3


  parent reply	other threads:[~2023-10-03  9:23 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-03  9:12 [PATCH v2 00/12] mempolicy: cleanups leading to NUMA mpol without vma Hugh Dickins
2023-10-03  9:15 ` [PATCH v2 01/12] hugetlbfs: drop shared NUMA mempolicy pretence Hugh Dickins
2023-10-03  9:16 ` [PATCH v2 02/12] kernfs: drop shared NUMA mempolicy hooks Hugh Dickins
2023-10-03  9:17 ` [PATCH v2 03/12] mempolicy: fix migrate_pages(2) syscall return nr_failed Hugh Dickins
2023-10-07  7:27   ` Huang, Ying
2023-10-03  9:19 ` [PATCH v2 04/12] mempolicy trivia: delete those ancient pr_debug()s Hugh Dickins
2023-10-03  9:20 ` [PATCH v2 05/12] mempolicy trivia: slightly more consistent naming Hugh Dickins
2023-10-03  9:21 ` [PATCH v2 06/12] mempolicy trivia: use pgoff_t in shared mempolicy tree Hugh Dickins
2023-10-03  9:22 ` Hugh Dickins [this message]
2023-10-03  9:24 ` [PATCH v2 08/12] mempolicy: remove confusing MPOL_MF_LAZY dead code Hugh Dickins
2023-10-03 22:28   ` Yang Shi
2023-10-03  9:25 ` [PATCH v2 09/12] mm: add page_rmappable_folio() wrapper Hugh Dickins
2023-10-03  9:26 ` [PATCH v2 10/12] mempolicy: alloc_pages_mpol() for NUMA policy without vma Hugh Dickins
2023-10-19 20:39   ` [PATCH v3 " Hugh Dickins
2023-10-23 16:53     ` domenico cerasuolo
2023-10-23 17:53       ` Andrew Morton
2023-10-23 18:10         ` domenico cerasuolo
2023-10-23 19:05           ` Johannes Weiner
2023-10-23 19:48             ` Hugh Dickins
2023-10-24  6:44             ` [PATCH] mempolicy: alloc_pages_mpol() for NUMA policy without vma: fix Hugh Dickins
2023-10-24  8:17               ` kernel test robot
2023-10-24 15:56                 ` Hugh Dickins
2023-10-24 16:09               ` [PATCH v2] " Hugh Dickins
2023-10-23 18:34     ` [PATCH v3 10/12] mempolicy: alloc_pages_mpol() for NUMA policy without vma Zi Yan
2023-10-23 21:10       ` Hugh Dickins
2023-10-23 21:13         ` Zi Yan
2023-10-03  9:27 ` [PATCH v2 11/12] mempolicy: mmap_lock is not needed while migrating folios Hugh Dickins
2023-10-03  9:29 ` [PATCH v2 12/12] mempolicy: migration attempt to match interleave nodes Hugh Dickins
2023-10-24  6:50   ` [PATCH] mempolicy: migration attempt to match interleave nodes: fix Hugh Dickins
2023-10-24 15:18     ` Liam R. Howlett
2023-10-24 16:32       ` Hugh Dickins
2023-10-24 16:45         ` Matthew Wilcox

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