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authorPaolo Bonzini <pbonzini@redhat.com>2019-11-21 10:01:51 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2019-11-21 12:03:40 +0100
commit46f4f0aabc61bfd365e1eb3c8a6d766d1a49cf32 (patch)
treef98a256ff3e4b20ca6252f7f80ce17759e57c6f2 /include/linux/gfp.h
parentMerge tag 'kvmarm-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD (diff)
parentKVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it (diff)
Merge branch 'kvm-tsx-ctrl' into HEAD
Conflicts: arch/x86/kvm/vmx/vmx.c
Diffstat (limited to 'include/linux/gfp.h')
-rw-r--r--include/linux/gfp.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index fb07b503dc45..61f2f6ff9467 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -325,6 +325,29 @@ static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
}
+/**
+ * gfpflags_normal_context - is gfp_flags a normal sleepable context?
+ * @gfp_flags: gfp_flags to test
+ *
+ * Test whether @gfp_flags indicates that the allocation is from the
+ * %current context and allowed to sleep.
+ *
+ * An allocation being allowed to block doesn't mean it owns the %current
+ * context. When direct reclaim path tries to allocate memory, the
+ * allocation context is nested inside whatever %current was doing at the
+ * time of the original allocation. The nested allocation may be allowed
+ * to block but modifying anything %current owns can corrupt the outer
+ * context's expectations.
+ *
+ * %true result from this function indicates that the allocation context
+ * can sleep and use anything that's associated with %current.
+ */
+static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
+{
+ return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
+ __GFP_DIRECT_RECLAIM;
+}
+
#ifdef CONFIG_HIGHMEM
#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
#else