Subject: + mm-mempolicy-remove-per-process-flag.patch added to -mm tree
To: rientjes@xxxxxxxxxx,cl@xxxxxxxxxxxxxxxxxxxx,cl@xxxxxxxxx,hannes@xxxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,mgorman@xxxxxxx,mhocko@xxxxxxx,oleg@xxxxxxxxxx,penberg@xxxxxxxxxx,riel@xxxxxxxxxx,thockin@xxxxxxxxxx,tj@xxxxxxxxxx,wujianguo@xxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 05 Mar 2014 13:21:37 -0800
The patch titled
Subject: mm, mempolicy: remove per-process flag
has been added to the -mm tree. Its filename is
mm-mempolicy-remove-per-process-flag.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mempolicy-remove-per-process-flag.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempolicy-remove-per-process-flag.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: David Rientjes <rientjes@xxxxxxxxxx>
Subject: mm, mempolicy: remove per-process flag
PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users.
There's no significant performance degradation to checking
current->mempolicy rather than current->flags & PF_MEMPOLICY in the
allocation path, especially since this is considered unlikely().
Running TCP_RR with netperf-2.4.5 through localhost on 16 cpu machine with
64GB of memory and without a mempolicy:
threads before after
16 1249409 1244487
32 1281786 1246783
48 1239175 1239138
64 1244642 1241841
80 1244346 1248918
96 1266436 1254316
112 1307398 1312135
128 1327607 1326502
Per-process flags are a scarce resource so we should free them up whenever
possible and make them available. We'll be using it shortly for memcg oom
reserves.
Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Jianguo Wu <wujianguo@xxxxxxxxxx>
Cc: Tim Hockin <thockin@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mempolicy.h | 1 -
include/linux/sched.h | 1 -
kernel/fork.c | 1 -
mm/mempolicy.c | 31 -------------------------------
mm/slab.c | 4 ++--
5 files changed, 2 insertions(+), 36 deletions(-)
diff -puN include/linux/mempolicy.h~mm-mempolicy-remove-per-process-flag include/linux/mempolicy.h
--- a/include/linux/mempolicy.h~mm-mempolicy-remove-per-process-flag
+++ a/include/linux/mempolicy.h
@@ -143,7 +143,6 @@ extern void numa_policy_init(void);
extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
enum mpol_rebind_step step);
extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
-extern void mpol_fix_fork_child_flag(struct task_struct *p);
extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
unsigned long addr, gfp_t gfp_flags,
diff -puN include/linux/sched.h~mm-mempolicy-remove-per-process-flag include/linux/sched.h
--- a/include/linux/sched.h~mm-mempolicy-remove-per-process-flag
+++ a/include/linux/sched.h
@@ -1825,7 +1825,6 @@ extern void thread_group_cputime_adjuste
#define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */
#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
-#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
#define PF_SUSPEND_TASK 0x80000000 /* this thread called freeze_processes and should not be frozen */
diff -puN kernel/fork.c~mm-mempolicy-remove-per-process-flag kernel/fork.c
--- a/kernel/fork.c~mm-mempolicy-remove-per-process-flag
+++ a/kernel/fork.c
@@ -1273,7 +1273,6 @@ static struct task_struct *copy_process(
p->mempolicy = NULL;
goto bad_fork_cleanup_cgroup;
}
- mpol_fix_fork_child_flag(p);
#endif
#ifdef CONFIG_CPUSETS
p->cpuset_mem_spread_rotor = NUMA_NO_NODE;
diff -puN mm/mempolicy.c~mm-mempolicy-remove-per-process-flag mm/mempolicy.c
--- a/mm/mempolicy.c~mm-mempolicy-remove-per-process-flag
+++ a/mm/mempolicy.c
@@ -738,36 +738,6 @@ static int mbind_range(struct mm_struct
return err;
}
-/*
- * Update task->flags PF_MEMPOLICY bit: set iff non-default
- * mempolicy. Allows more rapid checking of this (combined perhaps
- * with other PF_* flag bits) on memory allocation hot code paths.
- *
- * If called from outside this file, the task 'p' should -only- be
- * a newly forked child not yet visible on the task list, because
- * manipulating the task flags of a visible task is not safe.
- *
- * The above limitation is why this routine has the funny name
- * mpol_fix_fork_child_flag().
- *
- * It is also safe to call this with a task pointer of current,
- * which the static wrapper mpol_set_task_struct_flag() does,
- * for use within this file.
- */
-
-void mpol_fix_fork_child_flag(struct task_struct *p)
-{
- if (p->mempolicy)
- p->flags |= PF_MEMPOLICY;
- else
- p->flags &= ~PF_MEMPOLICY;
-}
-
-static void mpol_set_task_struct_flag(void)
-{
- mpol_fix_fork_child_flag(current);
-}
-
/* Set the process memory policy */
static long do_set_mempolicy(unsigned short mode, unsigned short flags,
nodemask_t *nodes)
@@ -804,7 +774,6 @@ static long do_set_mempolicy(unsigned sh
}
old = current->mempolicy;
current->mempolicy = new;
- mpol_set_task_struct_flag();
if (new && new->mode == MPOL_INTERLEAVE &&
nodes_weight(new->v.nodes))
current->il_next = first_node(new->v.nodes);
diff -puN mm/slab.c~mm-mempolicy-remove-per-process-flag mm/slab.c
--- a/mm/slab.c~mm-mempolicy-remove-per-process-flag
+++ a/mm/slab.c
@@ -3027,7 +3027,7 @@ out:
#ifdef CONFIG_NUMA
/*
- * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
+ * Try allocating on another node if PF_SPREAD_SLAB is a mempolicy is set.
*
* If we are in_interrupt, then process context, including cpusets and
* mempolicy, may not apply and should not be used for allocation policy.
@@ -3259,7 +3259,7 @@ __do_cache_alloc(struct kmem_cache *cach
{
void *objp;
- if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
+ if (current->mempolicy || unlikely(current->flags & PF_SPREAD_SLAB)) {
objp = alternate_node_alloc(cache, flags);
if (objp)
goto out;
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
mm-close-pagetail-race.patch
mm-page_alloc-make-first_page-visible-before-pagetail.patch
kthread-ensure-locality-of-task_struct-allocations.patch
arch-x86-mm-kmemcheck-kmemcheckc-use-kstrtoint-instead-of-sscanf.patch
mm-slab-slub-use-page-list-consistently-instead-of-page-lru.patch
mm-compaction-ignore-pageblock-skip-when-manually-invoking-compaction.patch
mm-vmscan-shrink_slab-rename-max_pass-freeable.patch
mm-hugetlb-mark-some-bootstrap-functions-as-__init.patch
mm-compaction-avoid-isolating-pinned-pages.patch
mm-compactionc-mark-function-as-static.patch
mm-memoryc-mark-functions-as-static.patch
mm-mmapc-mark-function-as-static.patch
mm-process_vm_accessc-mark-function-as-static.patch
mm-process_vm_accessc-mark-function-as-static-fix.patch
mm-page_cgroupc-mark-functions-as-static.patch
mm-nobootmemc-mark-function-as-static.patch
include-linux-mmh-remove-ifdef-condition.patch
mm-readaheadc-fix-readahead-failure-for-memoryless-numa-nodes-and-limit-readahead-pages.patch
mmnuma-reorganize-change_pmd_range.patch
mmnuma-reorganize-change_pmd_range-fix.patch
move-mmu-notifier-call-from-change_protection-to-change_pmd_range.patch
mm-exclude-memory-less-nodes-from-zone_reclaim.patch
memcg-slab-never-try-to-merge-memcg-caches.patch
memcg-slab-cleanup-memcg-cache-creation.patch
memcg-slab-separate-memcg-vs-root-cache-creation-paths.patch
memcg-slab-unregister-cache-from-memcg-before-starting-to-destroy-it.patch
memcg-slab-do-not-destroy-children-caches-if-parent-has-aliases.patch
slub-adjust-memcg-caches-when-creating-cache-alias.patch
slub-rework-sysfs-layout-for-memcg-caches.patch
mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags.patch
mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags-ignore-madv_hugepage-on-s390-to-prevent-sigsegv-in-qemu.patch
mm-thp-add-vm_init_def_mask-and-prctl_thp_disable.patch
exec-kill-the-unnecessary-mm-def_flags-setting-in-load_elf_binary.patch
fork-collapse-copy_flags-into-copy_process.patch
mm-mempolicy-rename-slab_node-for-clarity.patch
mm-mempolicy-remove-per-process-flag.patch
res_counter-remove-interface-for-locked-charging-and-uncharging.patch
kernel-resourcec-make-reallocate_resource-static.patch
mm-utilc-add-kstrimdup.patch
fault-injection-set-bounds-on-what-proc-self-make-it-fail-accepts.patch
fault-injection-set-bounds-on-what-proc-self-make-it-fail-accepts-fix.patch
linux-next.patch
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