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authorJérôme Glisse <jglisse@redhat.com>2017-09-08 16:12:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-08 18:26:46 -0700
commit6b368cd4a44ce95b33f1d31f2f932e6ae707f319 (patch)
tree9d22ab2947db9a2d2e275b3a25eec66ea0e0b132 /include/linux/migrate.h
parentd3df0a423397c9a1ae05c3857e8c04240dd85e68 (diff)
downloadlwn-6b368cd4a44ce95b33f1d31f2f932e6ae707f319.tar.gz
lwn-6b368cd4a44ce95b33f1d31f2f932e6ae707f319.zip
mm/hmm: avoid bloating arch that do not make use of HMM
This moves all new code including new page migration helper behind kernel Kconfig option so that there is no codee bloat for arch or user that do not want to use HMM or any of its associated features. arm allyesconfig (without all the patchset, then with and this patch): text data bss dec hex filename 83721896 46511131 27582964 157815991 96814b7 ../without/vmlinux 83722364 46511131 27582964 157816459 968168b vmlinux [jglisse@redhat.com: struct hmm is only use by HMM mirror functionality] Link: http://lkml.kernel.org/r/20170825213133.27286-1-jglisse@redhat.com [sfr@canb.auug.org.au: fix build (arm multi_v7_defconfig)] Link: http://lkml.kernel.org/r/20170828181849.323ab81b@canb.auug.org.au Link: http://lkml.kernel.org/r/20170818032858.7447-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/migrate.h')
-rw-r--r--include/linux/migrate.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index d4e6d12a0b40..643c7ae7d7b4 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -265,6 +265,7 @@ struct migrate_vma_ops {
void *private);
};
+#if defined(CONFIG_MIGRATE_VMA_HELPER)
int migrate_vma(const struct migrate_vma_ops *ops,
struct vm_area_struct *vma,
unsigned long start,
@@ -272,6 +273,18 @@ int migrate_vma(const struct migrate_vma_ops *ops,
unsigned long *src,
unsigned long *dst,
void *private);
+#else
+static inline int migrate_vma(const struct migrate_vma_ops *ops,
+ struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end,
+ unsigned long *src,
+ unsigned long *dst,
+ void *private)
+{
+ return -EINVAL;
+}
+#endif /* IS_ENABLED(CONFIG_MIGRATE_VMA_HELPER) */
#endif /* CONFIG_MIGRATION */