Re: [PATCH 15/18] fix compilation with !CONFIG_NUMA_BALANCING

[Rik van Riel <riel@redhat.com>]

On Mon, 15 Jul 2013 16:20:17 +0100
Mel Gorman <mgorman@suse.de> wrote:

> Ideally it would be possible to distinguish between NUMA hinting faults that
> are private to a task and those that are shared. If treated identically
> there is a risk that shared pages bounce between nodes depending on

Your patch 15 breaks the compile with !CONFIG_NUMA_BALANCING.

This little patch fixes it:


The code in change_pte_range unconditionally calls nidpid_to_pid,
even when CONFIG_NUMA_SCHED is disabled.  Returning -1 keeps the
value of last_nid at "don't care" and should result in the mprotect
code doing nothing NUMA-related when CONFIG_NUMA_SCHED is disabled.

Signed-off-by: Rik van Riel <riel@redhat.com>
---
 include/linux/mm.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 668f03c..0e0d190 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -731,6 +731,26 @@ static inline int page_nidpid_last(struct page *page)
 	return page_to_nid(page);
 }
 
+static inline int nidpid_to_nid(int nidpid)
+{
+	return -1;
+}
+
+static inline int nidpid_to_pid(int nidpid)
+{
+	return -1;
+}
+
+static inline int nid_pid_to_nidpid(int nid, int pid)
+{
+	return -1;
+}
+
+static inline bool nidpid_pid_unset(int nidpid)
+{
+	return 1;
+}
+
 static inline void page_nidpid_reset_last(struct page *page)
 {
 }