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Date: Sat, 17 Feb 2018 13:39:43 +0800
From: changbin.du@...el.com
To: corbet@....net, rostedt@...dmis.org
Cc: mingo@...nel.org, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org, Changbin Du <changbin.du@...el.com>
Subject: [PATCH 10/17] trace doc: convert trace/events-kmem.txt to rst format
From: Changbin Du <changbin.du@...el.com>
This converts the plain text documentation to reStructuredText format and
add it into Sphinx TOC tree. No essential content change.
Cc: Steven Rostedt <rostedt@...dmis.org>
Signed-off-by: Changbin Du <changbin.du@...el.com>
---
.../trace/{events-kmem.txt => events-kmem.rst} | 50 ++++++++++++++--------
Documentation/trace/index.rst | 1 +
2 files changed, 32 insertions(+), 19 deletions(-)
rename Documentation/trace/{events-kmem.txt => events-kmem.rst} (76%)
diff --git a/Documentation/trace/events-kmem.txt b/Documentation/trace/events-kmem.rst
similarity index 76%
rename from Documentation/trace/events-kmem.txt
rename to Documentation/trace/events-kmem.rst
index 1948004..5554841 100644
--- a/Documentation/trace/events-kmem.txt
+++ b/Documentation/trace/events-kmem.rst
@@ -1,22 +1,26 @@
- Subsystem Trace Points: kmem
+============================
+Subsystem Trace Points: kmem
+============================
The kmem tracing system captures events related to object and page allocation
within the kernel. Broadly speaking there are five major subheadings.
- o Slab allocation of small objects of unknown type (kmalloc)
- o Slab allocation of small objects of known type
- o Page allocation
- o Per-CPU Allocator Activity
- o External Fragmentation
+ - Slab allocation of small objects of unknown type (kmalloc)
+ - Slab allocation of small objects of known type
+ - Page allocation
+ - Per-CPU Allocator Activity
+ - External Fragmentation
This document describes what each of the tracepoints is and why they
might be useful.
1. Slab allocation of small objects of unknown type
===================================================
-kmalloc call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s
-kmalloc_node call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d
-kfree call_site=%lx ptr=%p
+::
+
+ kmalloc call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s
+ kmalloc_node call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d
+ kfree call_site=%lx ptr=%p
Heavy activity for these events may indicate that a specific cache is
justified, particularly if kmalloc slab pages are getting significantly
@@ -27,9 +31,11 @@ the allocation sites were.
2. Slab allocation of small objects of known type
=================================================
-kmem_cache_alloc call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s
-kmem_cache_alloc_node call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d
-kmem_cache_free call_site=%lx ptr=%p
+::
+
+ kmem_cache_alloc call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s
+ kmem_cache_alloc_node call_site=%lx ptr=%p bytes_req=%zu bytes_alloc=%zu gfp_flags=%s node=%d
+ kmem_cache_free call_site=%lx ptr=%p
These events are similar in usage to the kmalloc-related events except that
it is likely easier to pin the event down to a specific cache. At the time
@@ -38,10 +44,12 @@ but the call_site can usually be used to extrapolate that information.
3. Page allocation
==================
-mm_page_alloc page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s
-mm_page_alloc_zone_locked page=%p pfn=%lu order=%u migratetype=%d cpu=%d percpu_refill=%d
-mm_page_free page=%p pfn=%lu order=%d
-mm_page_free_batched page=%p pfn=%lu order=%d cold=%d
+::
+
+ mm_page_alloc page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s
+ mm_page_alloc_zone_locked page=%p pfn=%lu order=%u migratetype=%d cpu=%d percpu_refill=%d
+ mm_page_free page=%p pfn=%lu order=%d
+ mm_page_free_batched page=%p pfn=%lu order=%d cold=%d
These four events deal with page allocation and freeing. mm_page_alloc is
a simple indicator of page allocator activity. Pages may be allocated from
@@ -65,8 +73,10 @@ contention on the zone->lru_lock.
4. Per-CPU Allocator Activity
=============================
-mm_page_alloc_zone_locked page=%p pfn=%lu order=%u migratetype=%d cpu=%d percpu_refill=%d
-mm_page_pcpu_drain page=%p pfn=%lu order=%d cpu=%d migratetype=%d
+::
+
+ mm_page_alloc_zone_locked page=%p pfn=%lu order=%u migratetype=%d cpu=%d percpu_refill=%d
+ mm_page_pcpu_drain page=%p pfn=%lu order=%d cpu=%d migratetype=%d
In front of the page allocator is a per-cpu page allocator. It exists only
for order-0 pages, reduces contention on the zone->lock and reduces the
@@ -92,7 +102,9 @@ can be allocated and freed on the same CPU through some algorithm change.
5. External Fragmentation
=========================
-mm_page_alloc_extfrag page=%p pfn=%lu alloc_order=%d fallback_order=%d pageblock_order=%d alloc_migratetype=%d fallback_migratetype=%d fragmenting=%d change_ownership=%d
+::
+
+ mm_page_alloc_extfrag page=%p pfn=%lu alloc_order=%d fallback_order=%d pageblock_order=%d alloc_migratetype=%d fallback_migratetype=%d fragmenting=%d change_ownership=%d
External fragmentation affects whether a high-order allocation will be
successful or not. For some types of hardware, this is important although
diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst
index b1cb484..95586aa 100644
--- a/Documentation/trace/index.rst
+++ b/Documentation/trace/index.rst
@@ -13,3 +13,4 @@ Linux Tracing Technologies
uprobetracer
tracepoints
events
+ events-kmem
--
2.7.4
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