* [PATCH] mwrap 2.0.0 mwrap - LD_PRELOAD malloc wrapper for Ruby
@ 2018-07-20 9:25 5% Eric Wong
0 siblings, 0 replies; 3+ results
From: Eric Wong @ 2018-07-20 9:25 UTC (permalink / raw)
To: ruby-talk, mwrap-public
mwrap is designed to answer the question:
Which lines of Ruby are hitting malloc the most?
mwrap wraps all malloc-family calls to trace the Ruby source
location of such calls and bytes allocated at each callsite.
As of mwrap 2.0.0, it can also function as a leak detector
and show live allocations at every call site. Depending on
your application and workload, the overhead is roughly a 50%
increase memory and runtime.
It works best for allocations under GVL, but tries to track
numeric caller addresses for allocations made without GVL so you
can get an idea of how much memory usage certain extensions and
native libraries use.
It requires the concurrent lock-free hash table from the
Userspace RCU project: https://liburcu.org/
It does not require recompiling or rebuilding Ruby, but only
supports Ruby trunk (2.6.0dev+) on a few platforms:
* GNU/Linux
* FreeBSD (tested 11.1)
It may work on NetBSD, OpenBSD and DragonFly BSD.
Changes in 2.0.0:
This release includes significant changes to track live
allocations and frees. It can find memory leaks from malloc
with less overhead than valgrind's leakchecker and there is a
new Rack endpoint (MwrapRack) which can display live allocation
stats.
API additions:
* Mwrap#[] - https://80x24.org/mwrap/Mwrap.html#method-c-5B-5D
* Mwrap::SourceLocation - https://80x24.org/mwrap/Mwrap/SourceLocation.html
* MwrapRack - https://80x24.org/mwrap/MwrapRack.html
Incompatible changes:
* Mwrap.clear now an alias to Mwrap.reset; as it's unsafe
to implement the new Mwrap#[] API otherwise:
https://80x24.org/mwrap-public/20180716211933.5835-12-e@80x24.org/
26 changes since v1.0.0:
README: improve usage example
MANIFEST: add .document
add benchmark
use __attribute__((weak)) instead of dlsym
Mwrap.dump: do not segfault on invalid IO arg
bin/mwrap: support LISTEN_FDS env from systemd
support per-allocation headers for per-alloc tracking
mwrap: use malloc to do our own memalign
hold RCU read lock to insert each allocation
realloc: do not copy if allocation failed
internal_memalign: do not assume real_malloc succeeds
ensure ENOMEM is preserved in errno when appropriate
memalign: check alignment on all public functions
reduce stack usage from file names
resolve real_malloc earlier for C++ programs
allow analyzing live allocations via Mwrap[location]
alias Mwrap.clear to Mwrap.reset
implement accessors for SourceLocation
mwrap_aref: quiet -Wshorten-64-to-32 warning
fixes for FreeBSD 11.1...
use memrchr to extract address under glibc
do not track allocations for constructor and Init_
disable memalign tracking by default
support Mwrap.quiet to temporarily disable allocation tracking
mwrap_rack: Rack app to track live allocations
documentation updates for 2.0.0 release
^ permalink raw reply [relevance 5%]
* [PATCH 19/19] mwrap_rack: Rack app to track live allocations
2018-07-16 21:19 7% [PATCH 0/19] the heavy version of mwrap Eric Wong
@ 2018-07-16 21:19 5% ` Eric Wong
0 siblings, 0 replies; 3+ results
From: Eric Wong @ 2018-07-16 21:19 UTC (permalink / raw)
To: mwrap-public
Might as well be able to see and inspect what allocations
are alive when developing a Rack application.
Demo is available at https://80x24.org/MWRAP/each/2000 (note:
"MWRAP" is capitalized) This is also running "repobrowse",
which will eventually replace cgit on 80x24.org, but is NOT
running the main HTTPS termination at https://80x24.org/
Note: this demo machine is 32-bit, so yes, it will overflow
---
lib/mwrap_rack.rb | 105 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)
create mode 100644 lib/mwrap_rack.rb
diff --git a/lib/mwrap_rack.rb b/lib/mwrap_rack.rb
new file mode 100644
index 0000000..ef3872b
--- /dev/null
+++ b/lib/mwrap_rack.rb
@@ -0,0 +1,105 @@
+# Copyright (C) 2018 all contributors <mwrap@80x24.org>
+# License: GPL-2.0+ <https://www.gnu.org/licenses/gpl-2.0.txt>
+# frozen_string_literal: true
+require 'mwrap'
+require 'rack'
+require 'cgi'
+
+# Usage: mwrap rackup ...
+class MwrapRack
+ module HtmlResponse
+ def response
+ [ 200, {
+ 'Expires' => 'Fri, 01 Jan 1980 00:00:00 GMT',
+ 'Pragma' => 'no-cache',
+ 'Cache-Control' => 'no-cache, max-age=0, must-revalidate',
+ 'Content-Type' => 'text/html; charset=UTF-8',
+ }, self ]
+ end
+ end
+
+ class Each < Struct.new(:script_name, :min, :sort)
+ include HtmlResponse
+ HEADER = '<tr><th>' + %w(total allocations frees mean_life max_life
+ location).join('</th><th>') + '</th></tr>'
+ FIELDS = %w(total allocations frees mean_life max_life location)
+ def each
+ Mwrap.quiet do
+ t = -"Mwrap.each(#{min})"
+ sn = script_name
+ all = []
+ f = FIELDS.dup
+ sc = FIELDS.index(sort || 'total') || 0
+ f[sc] = -"<b>#{f[sc]}</b>"
+ f.map! do |hdr|
+ if hdr.start_with?('<b>')
+ hdr
+ else
+ -%Q(<a\nhref="#{sn}/each/#{min}?sort=#{hdr}">#{hdr}</a>)
+ end
+ end
+ Mwrap.each(min) do |loc, total, allocations, frees, age_sum, max_life|
+ mean_life = frees == 0 ? Float::INFINITY : age_sum/frees.to_f
+ all << [total,allocations,frees,mean_life,max_life,loc]
+ end
+ all.sort_by! { |cols| -cols[sc] }
+
+ yield(-"<html><head><title>#{t}</title></head>" \
+ "<body><h1>#{t}</h1>\n" \
+ "<h2>Current generation: #{GC.count}</h2>\n<table>\n" \
+ "<tr><th>#{f.join('</th><th>')}</th></tr>\n")
+ all.each do |cols|
+ loc = cols.pop
+ cols[3] = sprintf('%0.3f', cols[3]) # mean_life
+ href = -(+"#{sn}/at/#{CGI.escape(loc)}").encode!(xml: :attr)
+ yield(%Q(<tr><td>#{cols.join('</td><td>')}<td><a\nhref=#{
+ href}>#{-loc.encode(xml: :text)}</a></td></tr>\n))
+ cols.clear
+ end.clear
+ yield "</table></body></html>\n"
+ end
+ end
+ end
+
+ class EachAt < Struct.new(:loc)
+ include HtmlResponse
+ HEADER = '<tr><th>size</th><th>generation</th></tr>'
+
+ def each
+ t = loc.name.encode(xml: :text)
+ yield(-"<html><head><title>#{t}</title></head>" \
+ "<body><h1>live allocations at #{t}</h1>" \
+ "<h2>Current generation: #{GC.count}</h2>\n<table>#{HEADER}")
+ loc.each do |size, generation|
+ yield("<tr><td>#{size}</td><td>#{generation}</td></tr>\n")
+ end
+ yield "</table></body></html>\n"
+ end
+ end
+
+ def r404
+ [404,{'Content-Type'=>'text/plain'},["Not found\n"]]
+ end
+
+ def call(env)
+ case env['PATH_INFO']
+ when %r{\A/each/(\d+)\z}
+ min = $1.to_i
+ m = env['QUERY_STRING'].match(/\bsort=(\w+)/)
+ Each.new(env['SCRIPT_NAME'], min, m ? m[1] : nil).response
+ when %r{\A/at/(.*)\z}
+ loc = -CGI.unescape($1)
+ loc = Mwrap[loc] or return r404
+ EachAt.new(loc).response
+ when '/'
+ n = 2000
+ u = 'https://80x24.org/mwrap/README.html'
+ b = -('<html><head><title>Mwrap demo</title></head>' \
+ "<body><p><a href=\"each/#{n}\">allocations >#{n} bytes</a>" \
+ "<p><a href=\"#{u}\">#{u}</a></body></html>\n")
+ [ 200, {'Content-Type'=>'text/html','Content-Length'=>-b.size.to_s},[b]]
+ else
+ r404
+ end
+ end
+end
--
EW
^ permalink raw reply related [relevance 5%]
* [PATCH 0/19] the heavy version of mwrap
@ 2018-07-16 21:19 7% Eric Wong
2018-07-16 21:19 5% ` [PATCH 19/19] mwrap_rack: Rack app to track live allocations Eric Wong
0 siblings, 1 reply; 3+ results
From: Eric Wong @ 2018-07-16 21:19 UTC (permalink / raw)
To: mwrap-public
TL;DR: live demo of the new features running inside a Rack app:
https://80x24.org/MWRAP/each/2000
The following changes since commit 834de3bc0da4af53535d5c9d4975e546df9fb186:
bin/mwrap: support LISTEN_FDS env from systemd (2018-07-16 19:33:12 +0000)
are available in the Git repository at:
https://80x24.org/mwrap.git heavy
for you to fetch changes up to c432e3ad30aa247dbac8575af87b0c594365d3fd:
mwrap_rack: Rack app to track live allocations (2018-07-16 21:14:13 +0000)
----------------------------------------------------------------
Eric Wong (19):
support per-allocation headers for per-alloc tracking
mwrap: use malloc to do our own memalign
hold RCU read lock to insert each allocation
realloc: do not copy if allocation failed
internal_memalign: do not assume real_malloc succeeds
ensure ENOMEM is preserved in errno when appropriate
memalign: check alignment on all public functions
reduce stack usage from file names
resolve real_malloc earlier for C++ programs
allow analyzing live allocations via Mwrap[location]
alias Mwrap.clear to Mwrap.reset
implement accessors for SourceLocation
mwrap_aref: quiet -Wshorten-64-to-32 warning
fixes for FreeBSD 11.1...
use memrchr to extract address under glibc
do not track allocations for constructor and Init_
disable memalign tracking by default
support Mwrap.quiet to temporarily disable allocation tracking
mwrap_rack: Rack app to track live allocations
ext/mwrap/extconf.rb | 15 +
ext/mwrap/mwrap.c | 792 +++++++++++++++++++++++++++++++++++++++++++--------
lib/mwrap_rack.rb | 105 +++++++
test/test_mwrap.rb | 113 ++++++++
4 files changed, 901 insertions(+), 124 deletions(-)
create mode 100644 lib/mwrap_rack.rb
^ permalink raw reply [relevance 7%]
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2018-07-20 9:25 5% [PATCH] mwrap 2.0.0 mwrap - LD_PRELOAD malloc wrapper for Ruby Eric Wong
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