From: Michael Jeanson <mjeanson@efficios.com>
Date: Wed, 8 Jun 2022 16:56:36 +0000 (-0400)
Subject: fix: mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked() (v5.19)
X-Git-Url: https://git.lttng.org/?p=lttng-modules.git;a=commitdiff_plain;h=6229bbaa423832f6b7c7a658ad11e1d4242752ff

fix: mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked() (v5.19)

See upstream commit :

  commit 10e0f7530205799e7e971aba699a7cb3a47456de
  Author: Wonhyuk Yang <vvghjk1234@gmail.com>
  Date:   Thu May 19 14:08:54 2022 -0700

    mm/page_alloc: fix tracepoint mm_page_alloc_zone_locked()

    Currently, trace point mm_page_alloc_zone_locked() doesn't show correct
    information.

    First, when alloc_flag has ALLOC_HARDER/ALLOC_CMA, page can be allocated
    from MIGRATE_HIGHATOMIC/MIGRATE_CMA.  Nevertheless, tracepoint use
    requested migration type not MIGRATE_HIGHATOMIC and MIGRATE_CMA.

    Second, after commit 44042b4498728 ("mm/page_alloc: allow high-order pages
    to be stored on the per-cpu lists") percpu-list can store high order
    pages.  But trace point determine whether it is a refiil of percpu-list by
    comparing requested order and 0.

    To handle these problems, make mm_page_alloc_zone_locked() only be called
    by __rmqueue_smallest with correct migration type.  With a new argument
    called percpu_refill, it can show roughly whether it is a refill of
    percpu-list.

Change-Id: I2e4a57393757f12b9c5a4566c4d1102ee2474a09
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/include/instrumentation/events/kmem.h b/include/instrumentation/events/kmem.h
index 29c0fb7f..8c19e962 100644
--- a/include/instrumentation/events/kmem.h
+++ b/include/instrumentation/events/kmem.h
@@ -218,6 +218,50 @@ LTTNG_TRACEPOINT_EVENT_MAP(mm_page_alloc, kmem_mm_page_alloc,
 	)
 )
 
+#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,19,0))
+LTTNG_TRACEPOINT_EVENT_CLASS(kmem_mm_page,
+
+	TP_PROTO(struct page *page, unsigned int order, int migratetype,
+			int percpu_refill),
+
+	TP_ARGS(page, order, migratetype, percpu_refill),
+
+	TP_FIELDS(
+		ctf_integer_hex(struct page *, page, page)
+		ctf_integer(unsigned long, pfn,
+			page ? page_to_pfn(page) : -1UL)
+		ctf_integer(unsigned int, order, order)
+		ctf_integer(int, migratetype, migratetype)
+		ctf_integer(int, percpu_refill, percpu_refill)
+	)
+)
+
+LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(kmem_mm_page, mm_page_alloc_zone_locked,
+
+	kmem_mm_page_alloc_zone_locked,
+
+	TP_PROTO(struct page *page, unsigned int order, int migratetype,
+			int percpu_refill),
+
+	TP_ARGS(page, order, migratetype, percpu_refill)
+)
+
+LTTNG_TRACEPOINT_EVENT_MAP(mm_page_pcpu_drain,
+
+	kmem_mm_page_pcpu_drain,
+
+	TP_PROTO(struct page *page, unsigned int order, int migratetype),
+
+	TP_ARGS(page, order, migratetype),
+
+	TP_FIELDS(
+		ctf_integer(unsigned long, pfn,
+			page ? page_to_pfn(page) : -1UL)
+		ctf_integer(unsigned int, order, order)
+		ctf_integer(int, migratetype, migratetype)
+	)
+)
+#else
 LTTNG_TRACEPOINT_EVENT_CLASS(kmem_mm_page,
 
 	TP_PROTO(struct page *page, unsigned int order, int migratetype),
@@ -250,6 +294,7 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(kmem_mm_page, mm_page_pcpu_drain,
 
 	TP_ARGS(page, order, migratetype)
 )
+#endif
 
 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,19,2)	\
 	|| LTTNG_KERNEL_RANGE(3,14,36, 3,15,0)		\