From a4568f07d3f7ee47195ef2f4c339885734fe03bd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?T=E2=80=A2=C3=98=E2=80=A2R=E2=80=A2=C3=9C=E2=80=A2S?= Date: Wed, 16 Feb 2022 01:44:31 +0400 Subject: [PATCH] doc: capitalize valgrind MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PR-URL: https://github.com/nodejs/node/pull/41986 Reviewed-By: Benjamin Gruenbaum Reviewed-By: Matteo Collina Reviewed-By: Tobias Nießen Reviewed-By: Rich Trott Reviewed-By: Mestery Reviewed-By: Richard Lau Reviewed-By: Akhil Marsonya Reviewed-By: Darshan Sen --- ...d => investigating-native-memory-leaks.md} | 27 ++++++++++--------- 1 file changed, 15 insertions(+), 12 deletions(-) rename doc/contributing/{investigating_native_memory_leak.md => investigating-native-memory-leaks.md} (97%) diff --git a/doc/contributing/investigating_native_memory_leak.md b/doc/contributing/investigating-native-memory-leaks.md similarity index 97% rename from doc/contributing/investigating_native_memory_leak.md rename to doc/contributing/investigating-native-memory-leaks.md index 8c193d1285fe29..f9345b092737fa 100644 --- a/doc/contributing/investigating_native_memory_leak.md +++ b/doc/contributing/investigating-native-memory-leaks.md @@ -1,14 +1,14 @@ -# Investigating memory leaks with valgrind +# Investigating memory leaks with Valgrind A Node.js process may run out of memory due to excessive consumption of native memory. Native Memory is memory which is not managed by the V8 Garbage collector and is allocated either by the Node.js runtime, its dependencies or native [addons](https://nodejs.org/docs/latest/api/n-api.html). -This guide provides information on how to use valgrind to investigate these +This guide provides information on how to use Valgrind to investigate these issues on Linux platforms. -## valgrind +## Valgrind [Valgrind](https://valgrind.org/docs/manual/quick-start.html) is a tool available on Linux distributions which can be used to investigate @@ -16,9 +16,9 @@ memory usage including identifying memory leaks (memory which is allocated and not freed) and other memory related problems like double freeing memory. -To use valgrind: +To use Valgrind: -* Be patient, running under valgrind slows execution significantly +* Be patient, running under Valgrind slows execution significantly due to the checks being performed. * Reduce your test case to the smallest reproduce. Due to the slowdown it is important to run the minimum test case in order to be able to do it in @@ -35,7 +35,7 @@ apt-get install valgrind ## Invocation -The simplest invocation of valgrind is: +The simplest invocation of Valgrind is: ```console valgrind node test.js @@ -133,7 +133,7 @@ it along with the allocations (since it is not used) and Valgrind will not find any leaks since they will no longer exist in the code being run. -Running valgrind on this code shows the following: +Running Valgrind on this code shows the following: ```console user1@minikube1:~/valgrind/node-addon-examples/1_hello_world/napi$ valgrind node hello.js @@ -317,7 +317,7 @@ From the stack trace we can tell that the leak came from a native addon: What we can't tell is where in the native addon the memory is being allocated. This is because by default the addon is compiled without -the debug symbols which valgrind needs to be able to provide more +the debug symbols which Valgrind needs to be able to provide more information. ## Enabling debug symbols to get more information @@ -345,7 +345,7 @@ npm install --debug npm rebuild ``` -The next step is to run valgrind after the rebuild. This time the information +The next step is to run Valgrind after the rebuild. This time the information for the leaking location includes the name of the source file and the line number: @@ -385,7 +385,7 @@ This new output shows us exactly where the leak is occurring in the file `hello. If the leak is not in an addon and is instead in the Node.js binary itself, you may need to compile node yourself and turn on debug symbols. Looking at -this entry reported by valgrind, with a release binary we see: +this entry reported by Valgrind, with a release binary we see: ```console ==4174== 304 bytes in 1 blocks are possibly lost in loss record 27 of 35 @@ -409,7 +409,7 @@ its symbols using `-rdynamic` so that they can be used by addons. If the stack gives you enough information to track down where the leak is, that's great, otherwise the next step is to compile a debug build of Node.js. -To get additional information with valgrind: +To get additional information with Valgrind: * Check out the Node.js source corresponding to the release that you want to debug. For example: @@ -432,7 +432,7 @@ make -j4 `./configure --debug`, two binaries will have been built when `make` was run. You must use the one which is in `out/Debug`. -Running valgrind using the debug build of Node.js shows: +Running Valgrind using the debug build of Node.js shows: ```console ==44112== 592 bytes in 1 blocks are possibly lost in loss record 26 of 27 @@ -450,3 +450,6 @@ Running valgrind using the debug build of Node.js shows: Now we can see the specific file name and line in the Node.js code which caused the allocation (inspector\_agent.cc:140). + +We can examine that line (and its surrounding code) to +find a solution for the memory leak.