linux.git/include/trace/events/kmem.h, branch v3.2

vmscan: tracing: add trace events for kswapd wakeup, sleeping and direct reclaim

2010-08-10T03:44:59+00:00

Add two trace events for kswapd waking up and going asleep for the
purposes of tracking kswapd activity and two trace events for direct
reclaim beginning and ending.  The information can be used to work out how
much time a process or the system is spending on the reclamation of pages
and in the case of direct reclaim, how many pages were reclaimed for that
process.  High frequency triggering of these events could point to memory
pressure problems.

Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
Acked-by: Larry Woodman 
Cc: Dave Chinner 
Cc: Chris Mason 
Cc: Nick Piggin 
Cc: Rik van Riel 
Cc: Johannes Weiner 
Cc: Christoph Hellwig 
Cc: KAMEZAWA Hiroyuki 
Cc: KOSAKI Motohiro 
Cc: Andrea Arcangeli 
Cc: Michael Rubin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracing: Convert some kmem events to DEFINE_EVENT

2009-11-26T08:14:02+00:00

Use DECLARE_EVENT_CLASS to remove duplicate code:

   text    data     bss     dec     hex filename
 333987   69800   27228  431015   693a7 mm/built-in.o.old
 330030   69800   27228  427058   68432 mm/built-in.o

8 events are converted:

  kmem_alloc: kmalloc, kmem_cache_alloc
  kmem_alloc_node: kmalloc_node, kmem_cache_alloc_node
  kmem_free: kfree, kmem_cache_free
  mm_page: mm_page_alloc_zone_locked, mm_page_pcpu_drain

No change in functionality.

Signed-off-by: Li Zefan 
Acked-by: Pekka Enberg 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Mel Gorman 
LKML-Reference: <4B0E286A.2000405@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

tracing, page-allocator: add trace event for page traffic related to the buddy lists

2009-09-22T14:17:34+00:00

The page allocation trace event reports that a page was successfully
allocated but it does not specify where it came from.  When analysing
performance, it can be important to distinguish between pages coming from
the per-cpu allocator and pages coming from the buddy lists as the latter
requires the zone lock to the taken and more data structures to be
examined.

This patch adds a trace event for __rmqueue reporting when a page is being
allocated from the buddy lists.  It distinguishes between being called to
refill the per-cpu lists or whether it is a high-order allocation.
Similarly, this patch adds an event to catch when the PCP lists are being
drained a little and pages are going back to the buddy lists.

This is trickier to draw conclusions from but high activity on those
events could explain why there were a large number of cache misses on a
page-allocator-intensive workload.  The coalescing and splitting of
buddies involves a lot of writing of page metadata and cache line bounces
not to mention the acquisition of an interrupt-safe lock necessary to
enter this path.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
Reviewed-by: Ingo Molnar 
Cc: Larry Woodman 
Cc: Peter Zijlstra 
Cc: Li Ming Chun 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracing, page-allocator: add trace events for anti-fragmentation falling back to other migratetypes

2009-09-22T14:17:34+00:00

Fragmentation avoidance depends on being able to use free pages from lists
of the appropriate migrate type.  In the event this is not possible,
__rmqueue_fallback() selects a different list and in some circumstances
change the migratetype of the pageblock.  Simplistically, the more times
this event occurs, the more likely that fragmentation will be a problem
later for hugepage allocation at least but there are other considerations
such as the order of page being split to satisfy the allocation.

This patch adds a trace event for __rmqueue_fallback() that reports what
page is being used for the fallback, the orders of relevant pages, the
desired migratetype and the migratetype of the lists being used, whether
the pageblock changed type and whether this event is important with
respect to fragmentation avoidance or not.  This information can be used
to help analyse fragmentation avoidance and help decide whether
min_free_kbytes should be increased or not.

Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
Reviewed-by: Ingo Molnar 
Cc: Larry Woodman 
Cc: Peter Zijlstra 
Cc: Li Ming Chun 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracing, page-allocator: add trace events for page allocation and page freeing

2009-09-22T14:17:34+00:00

This patch adds trace events for the allocation and freeing of pages,
including the freeing of pagevecs.  Using the events, it will be known
what struct page and pfns are being allocated and freed and what the call
site was in many cases.

The page alloc tracepoints be used as an indicator as to whether the
workload was heavily dependant on the page allocator or not.  You can make
a guess based on vmstat but you can't get a per-process breakdown.
Depending on the call path, the call_site for page allocation may be
__get_free_pages() instead of a useful callsite.  Instead of passing down
a return address similar to slab debugging, the user should enable the
stacktrace and seg-addr options to get a proper stack trace.

The pagevec free tracepoint has a different usecase.  It can be used to
get a idea of how many pages are being dumped off the LRU and whether it
is kswapd doing the work or a process doing direct reclaim.

Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
Reviewed-by: Ingo Molnar 
Cc: Larry Woodman 
Cc: Peter Zijlstra 
Cc: Li Ming Chun 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tracing/events: Move TRACE_SYSTEM outside of include guard

2009-07-13T08:59:55+00:00

If TRACE_INCLDUE_FILE is defined, 
will be included and compiled, otherwise it will be


So TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.

Imaging this scenario:

 #include 
    -> TRACE_SYSTEM == foo
 ...
 #include 
    -> TRACE_SYSTEM == bar
 ...
 #define CREATE_TRACE_POINTS
 #include 
    -> TRACE_SYSTEM == bar !!!

and then bar.h will be included and compiled.

Signed-off-by: Li Zefan 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

tracing: add flag output for kmem events

2009-05-26T18:31:14+00:00

This patch changes the output for gfp_flags from being a simple hex value
to the actual names.

  gfp_flags=GFP_ATOMIC  instead of gfp_flags=00000020

And even

  gfp_flags=GFP_KERNEL instead of gfp_flags=000000d0

(Thanks to Frederic Weisbecker for pointing out that the first version
 had a bad order of GFP masks)

[ Impact: more human readable output from tracer ]

Acked-by: Eduard - Gabriel Munteanu 
Signed-off-by: Steven Rostedt 
Signed-off-by: Frederic Weisbecker

tracing/events: move trace point headers into include/trace/events

2009-04-15T02:05:43+00:00

Impact: clean up

Create a sub directory in include/trace called events to keep the
trace point headers in their own separate directory. Only headers that
declare trace points should be defined in this directory.

Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Neil Horman 
Cc: Zhao Lei 
Cc: Eduard - Gabriel Munteanu 
Cc: Pekka Enberg 
Signed-off-by: Steven Rostedt