[lttng-dev] [PATCH lttng-modules 1/3] Fix: Add gfp_flags arg to mm_vmscan_kswapd_wake for 4.17

[Michael Jeanson]

See upstream commit:

  commit 5ecd9d403ad081ed2de7b118c1e96124d4e0ba6c
  Author: David Rientjes <rientjes at google.com>
  Date:   Thu Apr 5 16:25:16 2018 -0700

    mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

    Kswapd will not wakeup if per-zone watermarks are not failing or if too
    many previous attempts at background reclaim have failed.

    This can be true if there is a lot of free memory available.  For high-
    order allocations, kswapd is responsible for waking up kcompactd for
    background compaction.  If the zone is not below its watermarks or
    reclaim has recently failed (lots of free memory, nothing left to
    reclaim), kcompactd does not get woken up.

    When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be
    woken up even if kswapd will not reclaim.  This allows high-order
    allocations, such as thp, to still trigger background compaction even
    when the zone has an abundance of free memory.

Signed-off-by: Michael Jeanson <mjeanson at efficios.com>
---
 instrumentation/events/lttng-module/mm_vmscan.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/instrumentation/events/lttng-module/mm_vmscan.h b/instrumentation/events/lttng-module/mm_vmscan.h
index a69b42f..9661c9d 100644
--- a/instrumentation/events/lttng-module/mm_vmscan.h
+++ b/instrumentation/events/lttng-module/mm_vmscan.h
@@ -84,6 +84,21 @@ LTTNG_TRACEPOINT_EVENT(mm_vmscan_kswapd_wake,
 
 #endif
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,17,0))
+LTTNG_TRACEPOINT_EVENT(mm_vmscan_wakeup_kswapd,
+
+	TP_PROTO(int nid, int zid, int order, gfp_t gfp_flags),
+
+	TP_ARGS(nid, zid, order, gfp_flags),
+
+	TP_FIELDS(
+		ctf_integer(int, nid, nid)
+		ctf_integer(int, zid, zid)
+		ctf_integer(int, order, order)
+		ctf_integer(gfp_t, gfp_flags, gfp_flags)
+	)
+)
+#else
 LTTNG_TRACEPOINT_EVENT(mm_vmscan_wakeup_kswapd,
 
 	TP_PROTO(int nid, int zid, int order),
@@ -96,6 +111,7 @@ LTTNG_TRACEPOINT_EVENT(mm_vmscan_wakeup_kswapd,
 		ctf_integer(int, order, order)
 	)
 )
+#endif
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,8,0))
 
-- 
2.7.4