[Cc Mel and Andrea - the thread started
http://lkml.kernel.org/r/20181226131446.330864...@intel.com]
On Fri 28-12-18 21:15:42, Wu Fengguang wrote:
> On Fri, Dec 28, 2018 at 01:15:15PM +0100, Michal Hocko wrote:
> > On Fri 28-12-18 17:42:08, Wu Fengguang wrote:
> > [...]
> > > Those look unnecessary complexities for this post. This v2 patchset
> > > mainly fulfills our first milestone goal: a minimal viable solution
> > > that's relatively clean to backport. Even when preparing for new
> > > upstreamable versions, it may be good to keep it simple for the
> > > initial upstream inclusion.
> >
> > On the other hand this is creating a new NUMA semantic and I would like
> > to have something long term thatn let's throw something in now and care
> > about long term later. So I would really prefer to talk about long term
> > plans first and only care about implementation details later.
>
> That makes good sense. FYI here are the several in-house patches that
> try to leverage (but not yet integrate with) NUMA balancing. The last
> one is brutal force hacking. They obviously break original NUMA
> balancing logic.
>
> Thanks,
> Fengguang
> >From ef41a542568913c8c62251021c3bc38b7a549440 Mon Sep 17 00:00:00 2001
> From: Liu Jingqi <jingqi....@intel.com>
> Date: Sat, 29 Sep 2018 23:29:56 +0800
> Subject: [PATCH 074/166] migrate: set PROT_NONE on the PTEs and let NUMA
> balancing
>
> Need to enable CONFIG_NUMA_BALANCING firstly.
> Set PROT_NONE on the PTEs that map to the page,
> and do the actual migration in the context of process which initiate
> migration.
>
> Signed-off-by: Liu Jingqi <jingqi....@intel.com>
> Signed-off-by: Fengguang Wu <fengguang...@intel.com>
> ---
> mm/migrate.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b27a287081c2..d933f6966601 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1530,6 +1530,21 @@ static int add_page_for_migration(struct mm_struct
> *mm, unsigned long addr,
> if (page_mapcount(page) > 1 && !migrate_all)
> goto out_putpage;
>
> + if (flags & MPOL_MF_SW_YOUNG) {
> + unsigned long start, end;
> + unsigned long nr_pte_updates = 0;
> +
> + start = max(addr, vma->vm_start);
> +
> + /* TODO: if huge page */
> + end = ALIGN(addr + (1 << PAGE_SHIFT), PAGE_SIZE);
> + end = min(end, vma->vm_end);
> + nr_pte_updates = change_prot_numa(vma, start, end);
> +
> + err = 0;
> + goto out_putpage;
> + }
> +
> if (PageHuge(page)) {
> if (PageHead(page)) {
> /* Check if the page is software young. */
> --
> 2.15.0
>
> >From e617e8c2034387cbed50bafa786cf83528dbe3df Mon Sep 17 00:00:00 2001
> From: Fengguang Wu <fengguang...@intel.com>
> Date: Sun, 30 Sep 2018 10:50:58 +0800
> Subject: [PATCH 075/166] migrate: consolidate MPOL_MF_SW_YOUNG behaviors
>
> - if page already in target node: SetPageReferenced
> - otherwise: change_prot_numa
>
> Signed-off-by: Fengguang Wu <fengguang...@intel.com>
> ---
> arch/x86/kvm/Kconfig | 1 +
> mm/migrate.c | 65
> +++++++++++++++++++++++++++++++---------------------
> 2 files changed, 40 insertions(+), 26 deletions(-)
>
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index 4c6dec47fac6..c103373536fc 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -100,6 +100,7 @@ config KVM_EPT_IDLE
> tristate "KVM EPT idle page tracking"
> depends on KVM_INTEL
> depends on PROC_PAGE_MONITOR
> + depends on NUMA_BALANCING
> ---help---
> Provides support for walking EPT to get the A bits on Intel
> processors equipped with the VT extensions.
> diff --git a/mm/migrate.c b/mm/migrate.c
> index d933f6966601..d944f031c9ea 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1500,6 +1500,8 @@ static int add_page_for_migration(struct mm_struct *mm,
> unsigned long addr,
> {
> struct vm_area_struct *vma;
> struct page *page;
> + unsigned long end;
> + unsigned int page_nid;
> unsigned int follflags;
> int err;
> bool migrate_all = flags & MPOL_MF_MOVE_ALL;
> @@ -1522,49 +1524,60 @@ static int add_page_for_migration(struct mm_struct
> *mm, unsigned long addr,
> if (!page)
> goto out;
>
> - err = 0;
> - if (page_to_nid(page) == node)
> - goto out_putpage;
> + page_nid = page_to_nid(page);
>
> err = -EACCES;
> if (page_mapcount(page) > 1 && !migrate_all)
> goto out_putpage;
>
> - if (flags & MPOL_MF_SW_YOUNG) {
> - unsigned long start, end;
> - unsigned long nr_pte_updates = 0;
> -
> - start = max(addr, vma->vm_start);
> -
> - /* TODO: if huge page */
> - end = ALIGN(addr + (1 << PAGE_SHIFT), PAGE_SIZE);
> - end = min(end, vma->vm_end);
> - nr_pte_updates = change_prot_numa(vma, start, end);
> -
> - err = 0;
> - goto out_putpage;
> - }
> -
> + err = 0;
> if (PageHuge(page)) {
> - if (PageHead(page)) {
> - /* Check if the page is software young. */
> - if (flags & MPOL_MF_SW_YOUNG)
> + if (!PageHead(page)) {
> + err = -EACCES;
> + goto out_putpage;
> + }
> + if (flags & MPOL_MF_SW_YOUNG) {
> + if (page_nid == node)
> SetPageReferenced(page);
> - isolate_huge_page(page, pagelist);
> - err = 0;
> + else if (PageAnon(page)) {
> + end = addr + (hpage_nr_pages(page) <<
> PAGE_SHIFT);
> + if (end <= vma->vm_end)
> + change_prot_numa(vma, addr, end);
> + }
> + goto out_putpage;
> }
> + if (page_nid == node)
> + goto out_putpage;
> + isolate_huge_page(page, pagelist);
> } else {
> struct page *head;
>
> head = compound_head(page);
> +
> + if (flags & MPOL_MF_SW_YOUNG) {
> + if (page_nid == node)
> + SetPageReferenced(head);
> + else {
> + unsigned long size;
> + size = hpage_nr_pages(head) << PAGE_SHIFT;
> + end = addr + size;
> + if (unlikely(addr & (size - 1)))
> + err = -EXDEV;
> + else if (likely(end <= vma->vm_end))
> + change_prot_numa(vma, addr, end);
> + else
> + err = -ERANGE;
> + }
> + goto out_putpage;
> + }
> + if (page_nid == node)
> + goto out_putpage;
> +
> err = isolate_lru_page(head);
> if (err)
> goto out_putpage;
>
> err = 0;
> - /* Check if the page is software young. */
> - if (flags & MPOL_MF_SW_YOUNG)
> - SetPageReferenced(head);
> list_add_tail(&head->lru, pagelist);
> mod_node_page_state(page_pgdat(head),
> NR_ISOLATED_ANON + page_is_file_cache(head),
> --
> 2.15.0
>
> >From a2d9740d1639f807868014c16dc9e2620d356f3c Mon Sep 17 00:00:00 2001
> From: Fengguang Wu <fengguang...@intel.com>
> Date: Sun, 30 Sep 2018 19:22:27 +0800
> Subject: [PATCH 076/166] mempolicy: force NUMA balancing
>
> Signed-off-by: Fengguang Wu <fengguang...@intel.com>
> ---
> mm/memory.c | 3 ++-
> mm/mempolicy.c | 5 -----
> 2 files changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index c467102a5cbc..20c7efdff63b 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3775,7 +3775,8 @@ static int numa_migrate_prep(struct page *page, struct
> vm_area_struct *vma,
> *flags |= TNF_FAULT_LOCAL;
> }
>
> - return mpol_misplaced(page, vma, addr);
> + return 0;
> + /* return mpol_misplaced(page, vma, addr); */
> }
>
> static vm_fault_t do_numa_page(struct vm_fault *vmf)
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index da858f794eb6..21dc6ba1d062 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2295,8 +2295,6 @@ int mpol_misplaced(struct page *page, struct
> vm_area_struct *vma, unsigned long
> int ret = -1;
>
> pol = get_vma_policy(vma, addr);
> - if (!(pol->flags & MPOL_F_MOF))
> - goto out;
>
> switch (pol->mode) {
> case MPOL_INTERLEAVE:
> @@ -2336,9 +2334,6 @@ int mpol_misplaced(struct page *page, struct
> vm_area_struct *vma, unsigned long
> /* Migrate the page towards the node whose CPU is referencing it */
> if (pol->flags & MPOL_F_MORON) {
> polnid = thisnid;
> -
> - if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
> - goto out;
> }
>
> if (curnid != polnid)
> --
> 2.15.0
>
--
Michal Hocko
SUSE Labs
