diff options
Diffstat (limited to 'lib/tools/doc')
| -rw-r--r-- | lib/tools/doc/src/lcnt.xml | 10 | ||||
| -rw-r--r-- | lib/tools/doc/src/lcnt_chapter.xml | 30 | ||||
| -rw-r--r-- | lib/tools/doc/src/make.xml | 26 | ||||
| -rw-r--r-- | lib/tools/doc/src/notes.xml | 2 |
4 files changed, 31 insertions, 37 deletions
diff --git a/lib/tools/doc/src/lcnt.xml b/lib/tools/doc/src/lcnt.xml index 9c8ce148e9..6e66a957ab 100644 --- a/lib/tools/doc/src/lcnt.xml +++ b/lib/tools/doc/src/lcnt.xml @@ -38,7 +38,7 @@ <modulesummary>A runtime system Lock Profiling tool.</modulesummary> <description> <p>The <c>lcnt</c> module is used to profile the internal ethread locks in the - Erlang Runtime System. With <c>lcnt</c> enabled, Internal counters in the + Erlang Runtime System. With <c>lcnt</c> enabled, internal counters in the runtime system are updated each time a lock is taken. The counters stores information about the number of acquisition tries and the number of collisions that has occurred during the acquisition tries. The counters also record the @@ -47,17 +47,17 @@ <p> The data produced by the lock counters will give an estimate on how well the runtime system will behave from a parallelizable view point for the - scenarios tested. This tool was mainly developed to help erlang runtime + scenarios tested. This tool was mainly developed to help Erlang runtime developers iron out potential and generic bottlenecks. </p> <p>Locks in the emulator are named after what type of resource they protect and where in the emulator they are initialized, those are lock 'classes'. Most of those locks are also instantiated several times, and given unique identifiers, to increase locking granularity. Typically an instantiated lock protects a disjunct set of - the resource, i.e ets-tables, processes or ports. In other cases it protects a - specific range of a resource, e.g. <c>pix_lock</c> which protects index to process + the resource, for example ets tables, processes or ports. In other cases it protects a + specific range of a resource, for example <c>pix_lock</c> which protects index to process mappings, and is given a unique number within the class. A unique lock in <c>lcnt</c> - is referenced by a name (class) and an identifier, <c>{Name, Id}</c>. + is referenced by a name (class) and an identifier: <c>{Name, Id}</c>. </p> <p>Some locks in the system are static and protects global resources, for example <c>bif_timers</c> and the <c>run_queue</c> locks. Other locks are dynamic and not diff --git a/lib/tools/doc/src/lcnt_chapter.xml b/lib/tools/doc/src/lcnt_chapter.xml index 6cfdb5cf1b..1981d66117 100644 --- a/lib/tools/doc/src/lcnt_chapter.xml +++ b/lib/tools/doc/src/lcnt_chapter.xml @@ -42,42 +42,32 @@ completed its access to the resource and unlocked it. The <c>lcnt</c> tool measures these lock conflicts. </p> <p> - Locks has an inherent cost in execution time and memory space. It takes time initialize, destroy, aquiring or releasing locks. To decrease lock contention it + Locks have an inherent cost in execution time and memory space. It takes time initialize, destroy, aquiring or releasing locks. To decrease lock contention it some times necessary to use finer grained locking strategies. This will usually also increase the locking overhead and hence there is a tradeoff between lock contention and overhead. In general, lock contention increases with the number of threads running concurrently. The <c>lcnt</c> tool does not measure locking overhead. </p> <section> <title> Enabling lock-counting </title> - <p>For investigation of locks in the emulator we use an internal tool called <c>lcnt</c> (short for lock-count). The VM needs to be compiled with this option enabled. To enable this, use:</p> + <p>For investigation of locks in the emulator we use an internal tool called <c>lcnt</c> (short for lock-count). The VM needs to be compiled with this option enabled. + To compile a lock-counting VM along with a normal VM, use:</p> <pre> cd $ERL_TOP -./configure --enable-lock-counter - </pre> - - <p> - Another way to enable this alongside a normal VM is to compile it at emulator directory level, much like a debug build. To compile it this way do the following, - </p> - <pre> -cd $ERL_TOP/erts/emulator -make lcnt FLAVOR=smp - </pre> - <p> and then starting Erlang with,</p> +./configure --enable-lock-counter</pre> + <p>Start the lock-counting VM like this:</p> <pre> -$ERL_TOP/bin/cerl -lcnt - </pre> - <p>To verify that you lock-counting enabled check that <c>[lock-counting]</c> appears in the status text when the VM is started.</p> +$ERL_TOP/bin/erl -emu_type lcnt</pre> + <p>To verify that lock counting is enabled check that <c>[lock-counting]</c> appears in the status text when the VM is started.</p> <pre> -Erlang R13B03 (erts-5.7.4) [source] [64-bit] [smp:8:8] [rq:8] [async-threads:0] [hipe] - [kernel-poll:false] [lock-counting] - </pre> +Erlang/OTP 20 [erts-9.0] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] + [kernel-poll:false] [lock-counting]</pre> </section> <section> <title>Getting started</title> <p>Once you have a lock counting enabled VM the module <c>lcnt</c> can be used. The module is intended to be used from the current running nodes shell. To access remote nodes use <c>lcnt:clear(Node)</c> and <c>lcnt:collect(Node)</c>. </p> <p>All locks are continuously monitored and its statistics updated. Use <c>lcnt:clear/0</c> to initially clear all counters before running any specific tests. This command will also reset the duration timer internally.</p> - <p>To retrieve lock statistics information use, <c>lcnt:collect/0,1</c>. The collect operation will start a <c>lcnt</c> server if it not already started. All collected data will be built into an erlang term and uploaded to the server and a duration time will also be uploaded. This duration is the time between <c>lcnt:clear/0,1</c> and <c>lcnt:collect/0,1</c>.</p> + <p>To retrieve lock statistics information, use <c>lcnt:collect/0,1</c>. The collect operation will start a <c>lcnt</c> server if it not already started. All collected data will be built into an Erlang term and uploaded to the server and a duration time will also be uploaded. This duration is the time between <c>lcnt:clear/0,1</c> and <c>lcnt:collect/0,1</c>.</p> <p>Once the data is collected to the server it can be filtered, sorted and printed in many different ways.</p> <p>See the <seealso marker="lcnt">reference manual</seealso> for a description of each function.</p> diff --git a/lib/tools/doc/src/make.xml b/lib/tools/doc/src/make.xml index fddf5ebd7b..123fcd4afc 100644 --- a/lib/tools/doc/src/make.xml +++ b/lib/tools/doc/src/make.xml @@ -5,7 +5,7 @@ <header> <copyright> <year>1996</year> - <year>2016</year> + <year>2017</year> <holder>Ericsson AB, All Rights Reserved</holder> </copyright> <legalnotice> @@ -43,15 +43,15 @@ <fsummary>Compile a set of modules.</fsummary> <type> <v>Options = [Option]</v> - <v> Option = noexec | load | netload | <compiler option></v> + <v> Option = noexec | load | netload | {emake, Emake} | <compiler option></v> </type> <desc> - <p>This function first looks in the current working directory - for a file named <c>Emakefile</c> (see below) specifying the - set of modules to compile and the compile options to use. If - no such file is found, the set of modules to compile - defaults to all modules in the current working - directory.</p> + <p>This function determines the set of modules to compile and the + compile options to use, by first looking for the <c>emake</c> make + option, if not present reads the configuration from a file named + <c>Emakefile</c> (see below). If no such file is found, the + set of modules to compile defaults to all modules in the + current working directory.</p> <p>Traversing the set of modules, it then recompiles every module for which at least one of the following conditions apply:</p> <list type="bulleted"> @@ -77,6 +77,9 @@ <item><c>netload</c> <br></br> Net load mode. Loads all recompiled modules on all known nodes.</item> + <item><c>{emake, Emake}</c> <br></br> + + Rather than reading the <c>Emakefile</c> specify configuration explicitly.</item> </list> <p>All items in <c>Options</c> that are not make options are assumed to be compiler options and are passed as-is to @@ -108,9 +111,10 @@ <section> <title>Emakefile</title> - <p><c>make:all/0,1</c> and <c>make:files/1,2</c> looks in the - current working directory for a file named <c>Emakefile</c>. If - it exists, <c>Emakefile</c> should contain elements like this:</p> + <p><c>make:all/0,1</c> and <c>make:files/1,2</c> first looks for + <c>{emake, Emake}</c> in options, then in the current working directory + for a file named <c>Emakefile</c>. If present <c>Emake</c> should + contain elements like this:</p> <code type="none"> Modules. {Modules,Options}. </code> diff --git a/lib/tools/doc/src/notes.xml b/lib/tools/doc/src/notes.xml index af20200d49..bc17fd5307 100644 --- a/lib/tools/doc/src/notes.xml +++ b/lib/tools/doc/src/notes.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2004</year><year>2016</year> + <year>2004</year><year>2017</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> |