All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mel Gorman <mgorman@techsingularity.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>,
	Bharata B Rao <bharata@amd.com>, Ingo Molnar <mingo@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 3/6] sched/numa: Trace decisions related to skipping VMAs
Date: Tue, 10 Oct 2023 09:31:40 +0100	[thread overview]
Message-ID: <20231010083143.19593-4-mgorman@techsingularity.net> (raw)
In-Reply-To: <20231010083143.19593-1-mgorman@techsingularity.net>

NUMA Balancing skip or scans VMAs for a variety of reasons. In preparation
for completing scans of VMAs regardless of PID access, trace the reasons
why a VMA was skipped. In a later patch, the tracing will be used to track
if a VMA was forcibly scanned.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 include/linux/sched/numa_balancing.h |  8 +++++
 include/trace/events/sched.h         | 50 ++++++++++++++++++++++++++++
 kernel/sched/fair.c                  | 17 +++++++---
 3 files changed, 71 insertions(+), 4 deletions(-)

diff --git a/include/linux/sched/numa_balancing.h b/include/linux/sched/numa_balancing.h
index 3988762efe15..c127a1509e2f 100644
--- a/include/linux/sched/numa_balancing.h
+++ b/include/linux/sched/numa_balancing.h
@@ -15,6 +15,14 @@
 #define TNF_FAULT_LOCAL	0x08
 #define TNF_MIGRATE_FAIL 0x10
 
+enum numa_vmaskip_reason {
+	NUMAB_SKIP_UNSUITABLE,
+	NUMAB_SKIP_SHARED_RO,
+	NUMAB_SKIP_INACCESSIBLE,
+	NUMAB_SKIP_SCAN_DELAY,
+	NUMAB_SKIP_PID_INACTIVE,
+};
+
 #ifdef CONFIG_NUMA_BALANCING
 extern void task_numa_fault(int last_node, int node, int pages, int flags);
 extern pid_t task_numa_group_id(struct task_struct *p);
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index fbb99a61f714..b0d0dbf491ea 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -664,6 +664,56 @@ DEFINE_EVENT(sched_numa_pair_template, sched_swap_numa,
 	TP_ARGS(src_tsk, src_cpu, dst_tsk, dst_cpu)
 );
 
+#ifdef CONFIG_NUMA_BALANCING
+#define NUMAB_SKIP_REASON					\
+	EM( NUMAB_SKIP_UNSUITABLE,		"unsuitable" )	\
+	EM( NUMAB_SKIP_SHARED_RO,		"shared_ro" )	\
+	EM( NUMAB_SKIP_INACCESSIBLE,		"inaccessible" )	\
+	EM( NUMAB_SKIP_SCAN_DELAY,		"scan_delay" )	\
+	EMe(NUMAB_SKIP_PID_INACTIVE,		"pid_inactive" )
+
+/* Redefine for export. */
+#undef EM
+#undef EMe
+#define EM(a, b)	TRACE_DEFINE_ENUM(a);
+#define EMe(a, b)	TRACE_DEFINE_ENUM(a);
+
+NUMAB_SKIP_REASON
+
+/* Redefine for symbolic printing. */
+#undef EM
+#undef EMe
+#define EM(a, b)	{ a, b },
+#define EMe(a, b)	{ a, b }
+
+TRACE_EVENT(sched_skip_vma_numa,
+
+	TP_PROTO(struct mm_struct *mm, struct vm_area_struct *vma,
+		 enum numa_vmaskip_reason reason),
+
+	TP_ARGS(mm, vma, reason),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, numa_scan_offset)
+		__field(unsigned long, vm_start)
+		__field(unsigned long, vm_end)
+		__field(enum numa_vmaskip_reason, reason)
+	),
+
+	TP_fast_assign(
+		__entry->numa_scan_offset	= mm->numa_scan_offset;
+		__entry->vm_start		= vma->vm_start;
+		__entry->vm_end			= vma->vm_end;
+		__entry->reason			= reason;
+	),
+
+	TP_printk("numa_scan_offset=%lX vm_start=%lX vm_end=%lX reason=%s",
+		  __entry->numa_scan_offset,
+		  __entry->vm_start,
+		  __entry->vm_end,
+		  __print_symbolic(__entry->reason, NUMAB_SKIP_REASON))
+);
+#endif /* CONFIG_NUMA_BALANCING */
 
 /*
  * Tracepoint for waking a polling cpu without an IPI.
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 81405627b9ed..0535c57f6a77 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3227,6 +3227,7 @@ static void task_numa_work(struct callback_head *work)
 	do {
 		if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
 			is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
+			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_UNSUITABLE);
 			continue;
 		}
 
@@ -3237,15 +3238,19 @@ static void task_numa_work(struct callback_head *work)
 		 * as migrating the pages will be of marginal benefit.
 		 */
 		if (!vma->vm_mm ||
-		    (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ)))
+		    (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ))) {
+			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_SHARED_RO);
 			continue;
+		}
 
 		/*
 		 * Skip inaccessible VMAs to avoid any confusion between
 		 * PROT_NONE and NUMA hinting ptes
 		 */
-		if (!vma_is_accessible(vma))
+		if (!vma_is_accessible(vma)) {
+			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_INACCESSIBLE);
 			continue;
+		}
 
 		/* Initialise new per-VMA NUMAB state. */
 		if (!vma->numab_state) {
@@ -3267,12 +3272,16 @@ static void task_numa_work(struct callback_head *work)
 		 * delay the scan for new VMAs.
 		 */
 		if (mm->numa_scan_seq && time_before(jiffies,
-						vma->numab_state->next_scan))
+						vma->numab_state->next_scan)) {
+			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_SCAN_DELAY);
 			continue;
+		}
 
 		/* Do not scan the VMA if task has not accessed */
-		if (!vma_is_accessed(vma))
+		if (!vma_is_accessed(vma)) {
+			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_PID_INACTIVE);
 			continue;
+		}
 
 		/*
 		 * RESET access PIDs regularly for old VMAs. Resetting after checking
-- 
2.35.3


  parent reply	other threads:[~2023-10-10  8:32 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-10  8:31 [PATCH 0/6] sched/numa: Complete scanning of partial and inactive VMAs Mel Gorman
2023-10-10  8:31 ` [PATCH 1/6] sched/numa: Document vma_numab_state fields Mel Gorman
2023-10-10  9:43   ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10  8:31 ` [PATCH 2/6] sched/numa: Rename vma_numab_state.access_pids Mel Gorman
2023-10-10  9:43   ` [tip: sched/core] sched/numa: Rename vma_numab_state::access_pids[] => ::pids_active[], ::next_pid_reset => ::pids_active_reset tip-bot2 for Mel Gorman
2023-10-10  8:31 ` Mel Gorman [this message]
2023-10-10  9:43   ` [tip: sched/core] sched/numa: Trace decisions related to skipping VMAs tip-bot2 for Mel Gorman
2023-10-10  8:31 ` [PATCH 4/6] sched/numa: Move up the access pid reset logic Mel Gorman
2023-10-10  9:43   ` [tip: sched/core] " tip-bot2 for Raghavendra K T
2023-10-10  8:31 ` [PATCH 5/6] sched/numa: Complete scanning of partial VMAs regardless of PID activity Mel Gorman
2023-10-10  9:43   ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 21:47   ` tip-bot2 for Mel Gorman
2023-10-10  8:31 ` [PATCH 6/6] sched/numa: Complete scanning of inactive VMAs when there is no alternative Mel Gorman
2023-10-10  9:23   ` Ingo Molnar
2023-10-10  9:57     ` Mel Gorman
2023-10-10 21:39       ` Ingo Molnar
2023-10-10 11:40     ` Raghavendra K T
2024-02-24  4:50       ` Raghavendra K T
2023-10-10  9:43   ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 11:42   ` [PATCH 6/6] " Raghavendra K T
2023-10-10 21:47   ` [tip: sched/core] " tip-bot2 for Mel Gorman
2023-10-10 11:39 ` [PATCH 0/6] sched/numa: Complete scanning of partial and inactive VMAs Raghavendra K T
2023-10-10 21:45   ` Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231010083143.19593-4-mgorman@techsingularity.net \
    --to=mgorman@techsingularity.net \
    --cc=bharata@amd.com \
    --cc=kprateek.nayak@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=raghavendra.kt@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.