From: Stephen Rothwell <sfr@canb•auug.org.au>
To: Thomas Gleixner <tglx@linutronix•de>, Ingo Molnar <mingo@elte•hu>,
"H. Peter Anvin" <hpa@zytor•com>,
Peter Zijlstra <peterz@infradead•org>
Cc: linux-next@vger•kernel.org, linux-kernel@vger•kernel.org,
KOSAKI Motohiro <kosaki.motohiro@jp•fujitsu.com>,
Andrew Morton <akpm@linux-foundation•org>,
Mel Gorman <mgorman@suse•de>,
Lee Schermerhorn <lee.schermerhorn@hp•com>
Subject: linux-next: manual merge of the tip tree with Linus' tree
Date: Wed, 10 Oct 2012 13:51:05 +1100 [thread overview]
Message-ID: <20121010135105.b45d6f8cc5b6b627446f993c@canb.auug.org.au> (raw)
[-- Attachment #1: Type: text/plain, Size: 4318 bytes --]
Hi all,
Today's linux-next merge of the tip tree got a conflict in mm/mempolicy.c
between commit 63f74ca21f1f ("mempolicy: fix refcount leak in
mpol_set_shared_policy()") from Linus' tree and commit 4d58c795f691
("mm/mpol: Check for misplaced page") from the tip tree.
I fixed it up (see below) and can carry the fix as necessary (no action
is required).
--
Cheers,
Stephen Rothwell sfr@canb•auug.org.au
diff --cc mm/mempolicy.c
index 0b78fb9,3360a8d..0000000
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@@ -2170,12 -2168,116 +2203,122 @@@ mpol_shared_policy_lookup(struct shared
return pol;
}
+static void sp_free(struct sp_node *n)
+{
+ mpol_put(n->policy);
+ kmem_cache_free(sn_cache, n);
+}
+
+ /**
+ * mpol_misplaced - check whether current page node is valid in policy
+ *
+ * @page - page to be checked
+ * @vma - vm area where page mapped
+ * @addr - virtual address where page mapped
+ * @multi - use multi-stage node binding
+ *
+ * Lookup current policy node id for vma,addr and "compare to" page's
+ * node id.
+ *
+ * Returns:
+ * -1 - not misplaced, page is in the right node
+ * node - node id where the page should be
+ *
+ * Policy determination "mimics" alloc_page_vma().
+ * Called from fault path where we know the vma and faulting address.
+ */
+ int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
+ unsigned long addr, int multi)
+ {
+ struct mempolicy *pol;
+ struct zone *zone;
+ int curnid = page_to_nid(page);
+ unsigned long pgoff;
+ int polnid = -1;
+ int ret = -1;
+
+ BUG_ON(!vma);
+
+ pol = get_vma_policy(current, vma, addr);
+ if (!(pol->flags & MPOL_F_MOF))
+ goto out;
+
+ switch (pol->mode) {
+ case MPOL_INTERLEAVE:
+ BUG_ON(addr >= vma->vm_end);
+ BUG_ON(addr < vma->vm_start);
+
+ pgoff = vma->vm_pgoff;
+ pgoff += (addr - vma->vm_start) >> PAGE_SHIFT;
+ polnid = offset_il_node(pol, vma, pgoff);
+ break;
+
+ case MPOL_PREFERRED:
+ if (pol->flags & MPOL_F_LOCAL)
+ polnid = numa_node_id();
+ else
+ polnid = pol->v.preferred_node;
+ break;
+
+ case MPOL_BIND:
+ /*
+ * allows binding to multiple nodes.
+ * use current page if in policy nodemask,
+ * else select nearest allowed node, if any.
+ * If no allowed nodes, use current [!misplaced].
+ */
+ if (node_isset(curnid, pol->v.nodes))
+ goto out;
+ (void)first_zones_zonelist(
+ node_zonelist(numa_node_id(), GFP_HIGHUSER),
+ gfp_zone(GFP_HIGHUSER),
+ &pol->v.nodes, &zone);
+ polnid = zone->node;
+ break;
+
+ default:
+ BUG();
+ }
+
+ /*
+ * Multi-stage node selection is used in conjunction with a periodic
+ * migration fault to build a temporal task<->page relation. By
+ * using a two-stage filter we remove short/unlikely relations.
+ *
+ * Using P(p) ~ n_p / n_t as per frequentist probability, we can
+ * equate a task's usage of a particular page (n_p) per total usage
+ * of this page (n_t) (in a given time-span) to a probability.
+ *
+ * Our periodic faults will then sample this probability and getting
+ * the same result twice in a row, given these samples are fully
+ * independent, is then given by P(n)^2, provided our sample period
+ * is sufficiently short compared to the usage pattern.
+ *
+ * This quadric squishes small probabilities, making it less likely
+ * we act on an unlikely task<->page relation.
+ *
+ * NOTE: effectively we're using task-home-node<->page-node relations
+ * since those are the only thing we can affect.
+ *
+ * NOTE: we're using task-home-node as opposed to the current node
+ * the task might be running on, since the task-home-node is the
+ * long-term node of this task, further reducing noise. Also see
+ * task_tick_numa().
+ */
+ if (multi && (pol->flags & MPOL_F_HOME)) {
+ int last_nid = page_xchg_last_nid(page, polnid);
+ if (last_nid != polnid)
+ goto out;
+ }
+
+ if (curnid != polnid)
+ ret = polnid;
+ out:
+ mpol_cond_put(pol);
+
+ return ret;
+ }
+
static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
pr_debug("deleting %lx-l%lx\n", n->start, n->end);
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next reply other threads:[~2012-10-10 2:51 UTC|newest]
Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-10 2:51 Stephen Rothwell [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-10-28 0:22 linux-next: manual merge of the tip tree with Linus' tree Stephen Rothwell
2025-10-28 1:10 ` Tejun Heo
2025-10-28 14:08 ` Peter Zijlstra
2025-05-13 6:54 Stephen Rothwell
2025-05-13 9:13 ` Ingo Molnar
2025-05-13 10:35 ` Stephen Rothwell
2025-05-13 6:52 Stephen Rothwell
2025-05-13 6:49 Stephen Rothwell
2025-05-13 6:45 Stephen Rothwell
2025-05-13 6:10 Stephen Rothwell
2025-05-13 6:00 Stephen Rothwell
2025-05-13 5:48 Stephen Rothwell
2025-05-13 23:09 ` Bagas Sanjaya
2024-02-08 1:30 Stephen Rothwell
2023-10-16 1:38 Stephen Rothwell
2023-08-09 2:15 Stephen Rothwell
2023-02-15 1:08 Stephen Rothwell
2023-02-15 11:15 ` Ingo Molnar
2022-07-13 5:08 Stephen Rothwell
2022-05-09 3:59 Stephen Rothwell
2022-01-04 2:45 Stephen Rothwell
2021-10-11 2:21 Stephen Rothwell
2021-10-11 20:48 ` Borislav Petkov
2020-11-06 2:39 Stephen Rothwell
2020-11-06 2:46 ` Steven Rostedt
2020-08-12 1:21 Stephen Rothwell
2020-06-11 1:00 Stephen Rothwell
2020-06-11 0:52 Stephen Rothwell
2020-06-11 10:43 ` Thomas Gleixner
2020-06-11 11:03 ` Stephen Rothwell
2020-06-10 1:49 Stephen Rothwell
2020-06-10 1:42 Stephen Rothwell
2020-05-18 5:10 Stephen Rothwell
2020-05-18 7:12 ` Borislav Petkov
2020-01-06 2:17 Stephen Rothwell
2020-01-06 6:53 ` Ingo Molnar
2019-12-20 1:53 Stephen Rothwell
2019-12-16 2:43 Stephen Rothwell
2019-12-03 2:10 Stephen Rothwell
2019-12-03 6:57 ` Ingo Molnar
2019-12-03 8:56 ` Stephen Rothwell
2019-09-02 7:31 Stephen Rothwell
2019-09-02 18:07 ` Ingo Molnar
2019-07-29 2:00 Stephen Rothwell
2019-03-06 5:53 Stephen Rothwell
2018-10-12 2:14 Stephen Rothwell
2018-10-12 2:18 ` Kees Cook
2018-10-12 10:47 ` Ingo Molnar
2018-10-12 18:56 ` Kees Cook
2018-06-07 1:53 Stephen Rothwell
2018-02-12 1:27 Stephen Rothwell
2018-02-12 7:19 ` Ingo Molnar
2018-02-06 0:54 Stephen Rothwell
2018-02-06 9:14 ` Peter Zijlstra
2018-02-06 0:44 Stephen Rothwell
2018-02-06 0:40 Stephen Rothwell
2018-02-06 12:52 ` Mathieu Desnoyers
2018-02-06 13:55 ` Will Deacon
2018-02-06 14:06 ` Mathieu Desnoyers
2018-02-06 14:11 ` Will Deacon
2018-02-06 17:05 ` Mathieu Desnoyers
2018-02-06 17:21 ` Will Deacon
2018-02-08 7:03 ` Ingo Molnar
2018-02-08 18:56 ` Will Deacon
2018-02-08 19:04 ` Mathieu Desnoyers
2018-02-09 18:25 ` Will Deacon
2018-02-09 20:35 ` Mathieu Desnoyers
2017-11-10 1:27 Stephen Rothwell
2017-05-22 3:27 Stephen Rothwell
2017-05-22 8:32 ` Mark Rutland
2017-05-22 21:44 ` Stephen Rothwell
2017-05-23 8:37 ` Mark Rutland
2016-02-03 0:09 Stephen Rothwell
2016-02-03 0:32 ` Toshi Kani
2015-09-18 1:12 Stephen Rothwell
2015-08-17 5:57 Stephen Rothwell
2015-07-06 0:08 Stephen Rothwell
2015-07-06 7:49 ` Paolo Bonzini
2015-07-06 21:34 ` Stephen Rothwell
2014-05-21 4:12 Stephen Rothwell
2014-05-21 4:24 ` H. Peter Anvin
2014-05-21 6:01 ` Ingo Molnar
2014-05-21 6:02 ` H. Peter Anvin
2014-05-21 6:05 ` Ingo Molnar
2014-05-21 6:10 ` Ingo Molnar
2014-05-21 4:12 Stephen Rothwell
2014-03-21 4:23 Stephen Rothwell
2014-03-21 8:47 ` Srivatsa S. Bhat
2014-02-18 3:09 Stephen Rothwell
2014-02-18 8:06 ` Hans-Christian Egtvedt
2014-02-18 14:15 ` Chen Gang
2014-01-30 1:42 Stephen Rothwell
2014-01-30 1:49 ` Andi Kleen
2014-01-30 1:58 ` Stephen Rothwell
2014-01-30 2:05 ` Andi Kleen
2014-01-28 0:43 Stephen Rothwell
2014-01-17 3:30 Stephen Rothwell
2014-01-17 17:27 ` Sören Brinkmann
2013-12-16 3:18 Stephen Rothwell
2013-09-04 4:24 Stephen Rothwell
2013-07-09 4:36 Stephen Rothwell
2012-12-03 4:19 Stephen Rothwell
2012-10-16 1:00 Stephen Rothwell
2012-10-21 16:29 ` Ingo Molnar
2012-10-15 0:32 Stephen Rothwell
2012-10-10 2:45 Stephen Rothwell
2012-06-26 4:36 Stephen Rothwell
2012-06-22 5:01 Stephen Rothwell
2012-06-04 3:52 Stephen Rothwell
2012-05-22 5:44 Stephen Rothwell
2012-01-03 5:16 Stephen Rothwell
2012-01-03 5:08 Stephen Rothwell
2012-01-03 8:06 ` Ingo Molnar
2012-01-03 8:36 ` Stephen Rothwell
2011-04-14 3:14 Stephen Rothwell
2011-04-14 9:02 ` Peter Zijlstra
2011-04-14 9:25 ` Ingo Molnar
2011-04-08 5:02 Stephen Rothwell
2011-03-16 5:08 Stephen Rothwell
2011-03-16 8:50 ` Sebastian Andrzej Siewior
2011-03-16 11:02 ` Stephen Rothwell
2010-10-22 2:08 Stephen Rothwell
2010-10-06 2:47 Stephen Rothwell
2010-09-23 3:32 Stephen Rothwell
2010-07-26 3:39 Stephen Rothwell
2010-01-18 7:08 Stephen Rothwell
2010-01-18 7:50 ` Ingo Molnar
2010-01-18 8:59 ` Stephen Rothwell
2009-12-09 4:06 Stephen Rothwell
2009-09-24 4:07 Stephen Rothwell
2009-09-24 8:33 ` Ingo Molnar
2009-09-24 9:23 ` Stephen Rothwell
2009-08-19 6:07 Stephen Rothwell
2009-08-19 10:37 ` Ingo Molnar
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