Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpm...
authorAndrea Arcangeli <aarcange@redhat.com>
Tue, 13 Aug 2019 22:37:50 +0000 (15:37 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 13 Aug 2019 23:06:52 +0000 (16:06 -0700)
Patch series "reapply: relax __GFP_THISNODE for MADV_HUGEPAGE mappings".

The fixes for what was originally reported as "pathological THP
behavior" we rightfully reverted to be sure not to introduced
regressions at end of a merge window after a severe regression report
from the kernel bot.  We can safely re-apply them now that we had time
to analyze the problem.

The mm process worked fine, because the good fixes were eventually
committed upstream without excessive delay.

The regression reported by the kernel bot however forced us to revert
the good fixes to be sure not to introduce regressions and to give us
the time to analyze the issue further.  The silver lining is that this
extra time allowed to think more at this issue and also plan for a
future direction to improve things further in terms of THP NUMA
locality.

This patch (of 2):

This reverts commit 356ff8a9a78fb35d ("Revert "mm, thp: consolidate THP
gfp handling into alloc_hugepage_direct_gfpmask").  So it reapplies
89c83fb539f954 ("mm, thp: consolidate THP gfp handling into
alloc_hugepage_direct_gfpmask").

Consolidation of the THP allocation flags at the same place was meant to
be a clean up to easier handle otherwise scattered code which is
imposing a maintenance burden.  There were no real problems observed
with the gfp mask consolidation but the reversion was rushed through
without a larger consensus regardless.

This patch brings the consolidation back because this should make the
long term maintainability easier as well as it should allow future
changes to be less error prone.

[mhocko@kernel.org: changelog additions]
Link: http://lkml.kernel.org/r/20190503223146.2312-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/gfp.h
mm/huge_memory.c
mm/mempolicy.c
mm/shmem.c

index fb07b503dc453ddfe16c5f0f959d46be01ad55ba..f33881688f42b2d6605d4f868546fbc06b1cd778 100644 (file)
@@ -510,22 +510,18 @@ alloc_pages(gfp_t gfp_mask, unsigned int order)
 }
 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
                        struct vm_area_struct *vma, unsigned long addr,
-                       int node, bool hugepage);
-#define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
-       alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
+                       int node);
 #else
 #define alloc_pages(gfp_mask, order) \
                alloc_pages_node(numa_node_id(), gfp_mask, order)
-#define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
-       alloc_pages(gfp_mask, order)
-#define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
+#define alloc_pages_vma(gfp_mask, order, vma, addr, node)\
        alloc_pages(gfp_mask, order)
 #endif
 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
 #define alloc_page_vma(gfp_mask, vma, addr)                    \
-       alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
+       alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id())
 #define alloc_page_vma_node(gfp_mask, vma, addr, node)         \
-       alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
+       alloc_pages_vma(gfp_mask, 0, vma, addr, node)
 
 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
index 1334ede667a82aa1d5701526836c7f54487e9996..f7e388b8662d83a03b965be80f8aa3ceaea0d92a 100644 (file)
@@ -644,30 +644,30 @@ release:
  *         available
  * never: never stall for any thp allocation
  */
-static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma)
+static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma, unsigned long addr)
 {
        const bool vma_madvised = !!(vma->vm_flags & VM_HUGEPAGE);
+       const gfp_t gfp_mask = GFP_TRANSHUGE_LIGHT | __GFP_THISNODE;
 
        /* Always do synchronous compaction */
        if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags))
-               return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY);
+               return GFP_TRANSHUGE | __GFP_THISNODE |
+                      (vma_madvised ? 0 : __GFP_NORETRY);
 
        /* Kick kcompactd and fail quickly */
        if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags))
-               return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM;
+               return gfp_mask | __GFP_KSWAPD_RECLAIM;
 
        /* Synchronous compaction if madvised, otherwise kick kcompactd */
        if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags))
-               return GFP_TRANSHUGE_LIGHT |
-                       (vma_madvised ? __GFP_DIRECT_RECLAIM :
-                                       __GFP_KSWAPD_RECLAIM);
+               return gfp_mask | (vma_madvised ? __GFP_DIRECT_RECLAIM :
+                                                 __GFP_KSWAPD_RECLAIM);
 
        /* Only do synchronous compaction if madvised */
        if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags))
-               return GFP_TRANSHUGE_LIGHT |
-                      (vma_madvised ? __GFP_DIRECT_RECLAIM : 0);
+               return gfp_mask | (vma_madvised ? __GFP_DIRECT_RECLAIM : 0);
 
-       return GFP_TRANSHUGE_LIGHT;
+       return gfp_mask;
 }
 
 /* Caller must hold page table lock. */
@@ -739,8 +739,8 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
                        pte_free(vma->vm_mm, pgtable);
                return ret;
        }
-       gfp = alloc_hugepage_direct_gfpmask(vma);
-       page = alloc_hugepage_vma(gfp, vma, haddr, HPAGE_PMD_ORDER);
+       gfp = alloc_hugepage_direct_gfpmask(vma, haddr);
+       page = alloc_pages_vma(gfp, HPAGE_PMD_ORDER, vma, haddr, numa_node_id());
        if (unlikely(!page)) {
                count_vm_event(THP_FAULT_FALLBACK);
                return VM_FAULT_FALLBACK;
@@ -1347,8 +1347,9 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
 alloc:
        if (__transparent_hugepage_enabled(vma) &&
            !transparent_hugepage_debug_cow()) {
-               huge_gfp = alloc_hugepage_direct_gfpmask(vma);
-               new_page = alloc_hugepage_vma(huge_gfp, vma, haddr, HPAGE_PMD_ORDER);
+               huge_gfp = alloc_hugepage_direct_gfpmask(vma, haddr);
+               new_page = alloc_pages_vma(huge_gfp, HPAGE_PMD_ORDER, vma,
+                               haddr, numa_node_id());
        } else
                new_page = NULL;
 
index 547cd403ed020eb17f260829942be7b0c35d5e47..9c9877a43d5832eb93c5694f36faf3afc0d8663e 100644 (file)
@@ -1180,8 +1180,8 @@ static struct page *new_page(struct page *page, unsigned long start)
        } else if (PageTransHuge(page)) {
                struct page *thp;
 
-               thp = alloc_hugepage_vma(GFP_TRANSHUGE, vma, address,
-                                        HPAGE_PMD_ORDER);
+               thp = alloc_pages_vma(GFP_TRANSHUGE, HPAGE_PMD_ORDER, vma,
+                               address, numa_node_id());
                if (!thp)
                        return NULL;
                prep_transhuge_page(thp);
@@ -2083,7 +2083,6 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
  *     @vma:  Pointer to VMA or NULL if not available.
  *     @addr: Virtual Address of the allocation. Must be inside the VMA.
  *     @node: Which node to prefer for allocation (modulo policy).
- *     @hugepage: for hugepages try only the preferred node if possible
  *
  *     This function allocates a page from the kernel page pool and applies
  *     a NUMA policy associated with the VMA or the current process.
@@ -2094,7 +2093,7 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
  */
 struct page *
 alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
-               unsigned long addr, int node, bool hugepage)
+               unsigned long addr, int node)
 {
        struct mempolicy *pol;
        struct page *page;
@@ -2112,31 +2111,6 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
                goto out;
        }
 
-       if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
-               int hpage_node = node;
-
-               /*
-                * For hugepage allocation and non-interleave policy which
-                * allows the current node (or other explicitly preferred
-                * node) we only try to allocate from the current/preferred
-                * node and don't fall back to other nodes, as the cost of
-                * remote accesses would likely offset THP benefits.
-                *
-                * If the policy is interleave, or does not allow the current
-                * node in its nodemask, we allocate the standard way.
-                */
-               if (pol->mode == MPOL_PREFERRED && !(pol->flags & MPOL_F_LOCAL))
-                       hpage_node = pol->v.preferred_node;
-
-               nmask = policy_nodemask(gfp, pol);
-               if (!nmask || node_isset(hpage_node, *nmask)) {
-                       mpol_cond_put(pol);
-                       page = __alloc_pages_node(hpage_node,
-                                               gfp | __GFP_THISNODE, order);
-                       goto out;
-               }
-       }
-
        nmask = policy_nodemask(gfp, pol);
        preferred_nid = policy_node(gfp, pol, node);
        page = __alloc_pages_nodemask(gfp, order, preferred_nid, nmask);
index 626d8c74b973f173d3062ee118580b649d35073a..2bed4761f2795695b2e970c304f8985aeacef9f6 100644 (file)
@@ -1466,7 +1466,7 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp,
 
        shmem_pseudo_vma_init(&pvma, info, hindex);
        page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN,
-                       HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), true);
+                       HPAGE_PMD_ORDER, &pvma, 0, numa_node_id());
        shmem_pseudo_vma_destroy(&pvma);
        if (page)
                prep_transhuge_page(page);