From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: akpm@linux-foundation.org, Michal Hocko <mhocko@kernel.org>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
David Gibson <david@gibson.dropbear.id.au>,
Andrea Arcangeli <aarcange@redhat.com>,
mpe@ellerman.id.au
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: [PATCH V7 1/4] mm/cma: Add PF flag to force non cma alloc
Date: Mon, 14 Jan 2019 15:24:33 +0530 [thread overview]
Message-ID: <20190114095438.32470-2-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20190114095438.32470-1-aneesh.kumar@linux.ibm.com>
This patch adds PF_MEMALLOC_NOCMA which make sure any allocation in that context
is marked non-movable and hence cannot be satisfied by CMA region.
This is useful with get_user_pages_longterm where we want to take a page pin by
migrating pages from CMA region. Marking the section PF_MEMALLOC_NOCMA ensures
that we avoid unnecessary page migration later.
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
include/linux/sched.h | 1 +
include/linux/sched/mm.h | 48 +++++++++++++++++++++++++++++++++-------
2 files changed, 41 insertions(+), 8 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 224666226e87..687b0edf97b2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1406,6 +1406,7 @@ extern struct pid *cad_pid;
#define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
#define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */
+#define PF_MEMALLOC_NOCMA 0x02000000 /* All allocation request will have _GFP_MOVABLE cleared */
#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_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 3bfa6a0cbba4..0cd9f10423fb 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -148,17 +148,25 @@ static inline bool in_vfork(struct task_struct *tsk)
* Applies per-task gfp context to the given allocation flags.
* PF_MEMALLOC_NOIO implies GFP_NOIO
* PF_MEMALLOC_NOFS implies GFP_NOFS
+ * PF_MEMALLOC_NOCMA implies no allocation from CMA region.
*/
static inline gfp_t current_gfp_context(gfp_t flags)
{
- /*
- * NOIO implies both NOIO and NOFS and it is a weaker context
- * so always make sure it makes precedence
- */
- if (unlikely(current->flags & PF_MEMALLOC_NOIO))
- flags &= ~(__GFP_IO | __GFP_FS);
- else if (unlikely(current->flags & PF_MEMALLOC_NOFS))
- flags &= ~__GFP_FS;
+ if (unlikely(current->flags &
+ (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA))) {
+ /*
+ * NOIO implies both NOIO and NOFS and it is a weaker context
+ * so always make sure it makes precedence
+ */
+ if (current->flags & PF_MEMALLOC_NOIO)
+ flags &= ~(__GFP_IO | __GFP_FS);
+ else if (current->flags & PF_MEMALLOC_NOFS)
+ flags &= ~__GFP_FS;
+#ifdef CONFIG_CMA
+ if (current->flags & PF_MEMALLOC_NOCMA)
+ flags &= ~__GFP_MOVABLE;
+#endif
+ }
return flags;
}
@@ -248,6 +256,30 @@ static inline void memalloc_noreclaim_restore(unsigned int flags)
current->flags = (current->flags & ~PF_MEMALLOC) | flags;
}
+#ifdef CONFIG_CMA
+static inline unsigned int memalloc_nocma_save(void)
+{
+ unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
+
+ current->flags |= PF_MEMALLOC_NOCMA;
+ return flags;
+}
+
+static inline void memalloc_nocma_restore(unsigned int flags)
+{
+ current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
+}
+#else
+static inline unsigned int memalloc_nocma_save(void)
+{
+ return 0;
+}
+
+static inline void memalloc_nocma_restore(unsigned int flags)
+{
+}
+#endif
+
#ifdef CONFIG_MEMCG
/**
* memalloc_use_memcg - Starts the remote memcg charging scope.
--
2.20.1
next prev parent reply other threads:[~2019-01-14 9:54 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-14 9:54 [PATCH V7 0/4] mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region Aneesh Kumar K.V
2019-01-14 9:54 ` Aneesh Kumar K.V [this message]
2019-01-29 22:52 ` [PATCH V7 1/4] mm/cma: Add PF flag to force non cma alloc Andrew Morton
2019-01-14 9:54 ` [PATCH V7 2/4] mm: Update get_user_pages_longterm to migrate pages allocated from CMA region Aneesh Kumar K.V
2019-01-14 9:54 ` Aneesh Kumar K.V
2019-01-14 9:54 ` [PATCH V7 3/4] powerpc/mm/iommu: Allow migration of cma allocated pages during mm_iommu_do_alloc Aneesh Kumar K.V
2019-01-30 11:34 ` Michael Ellerman
2019-01-31 4:42 ` Aneesh Kumar K.V
2019-01-14 9:54 ` [PATCH V7 4/4] powerpc/mm/iommu: Allow large IOMMU page size only for hugetlb backing Aneesh Kumar K.V
2019-01-14 9:54 ` [PATCH V7 5/5] testing Aneesh Kumar K.V
2019-01-15 11:25 ` Aneesh Kumar K.V
2019-01-29 22:56 ` [PATCH V7 0/4] mm/kvm/vfio/ppc64: Migrate compound pages out of CMA region Andrew Morton
2019-02-26 23:53 ` Andrew Morton
2019-02-27 8:52 ` Aneesh Kumar K.V
2019-02-27 11:29 ` Michael Ellerman
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