Memory Usage

Command Function

Collects performance data about memory allocation and release, and checks whether any allocated memory space has not been released.

Syntax

devkit doctor memalloc [-h] [-l {0,1,2,3}] [--package] [-o <file>] [-d <sec>] [-i <sec>] [-t n] [-z <byte>] [-Z <byte>] [-p PID] [workload ...] 

The tool can collect data of a specified application. Replace [workload workload...] in the command with the application path and application parameter.
This command is unavailable on SUSE Linux.
This function works based on eBPF and requires the root user.

Parameter Description

**Table 1** Parameter Description
Parameter	Option	Description
-h/--help	-	Obtains help information. This parameter is optional.
-l/--log-level	0/1/2/3	Log level, which defaults to 2. This parameter is optional. NOTE: The default level is 2 (WARNING). 0: DEBUG 1: INFO 2: WARNING 3: ERROR
--package	-	Indicates whether to import data to the database and generate compressed packages in the specified output path. This parameter is optional.
-o/--output	-	Report package name and output path. If you enter a name only, the report package is generated in the current directory by default. This option must be used together with --package.
-d/--duration	-	Collection duration, in seconds. By default collection does not stop until the application stops running. You can press Ctrl+C to stop the collection and start analysis. This parameter is optional.
-i/--interval	-	Collection interval, in seconds. This parameter is optional. The default value is 1 second. The value ranges from 1 to 60 seconds and cannot exceed the collection duration.
-t/--top	-	Maximum number of stacks to be displayed in the report, which defaults to 5 (if the value is less than 5, the actual number of stacks will be displayed). The value ranges from 5 to 15. The report content is sorted by stack size. This parameter is optional.
-z/--min-size	-	Minimum memory usage collected each time, in bytes. The value must be greater than or equal to 1. This parameter is optional.
-Z/--max-size	-	Maximum memory usage collected each time, in bytes. The value must be greater than or equal to 2. This parameter is optional.
-p/--pid	-	ID of the process to be collected, which defaults to -1, indicating that the kernel-mode memory usage is collected. This parameter is optional.

Example

devkit doctor memalloc -d 5 --package /opt/testdemo/mem_leak

In the preceding command, -d 5 indicates that the collection duration is 5 seconds, --package indicates that the report data is generated as a TAR package, and /opt/testdemo/mem_leak indicates the path to the application to be analyzed. You can obtain the application source code from GitHub.

Command output:

Executing "/opt/testdemo/mem_leak" and tracing the resulting process.
Attaching to App, fork pid = 3725254, Ctrl+C to quit.
Memory Allocate Summary Report-1                        Time:2025/08/18 15:57:21
================================================================================
No stacks with outstanding allocations.
Memory Allocate Summary Report-2                        Time:2025/08/18 15:57:22
================================================================================
Top 1 stacks with outstanding allocations:
Top 1 Stack
————————————————————————————————————————————————————————————————————
stack_name                mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
stack_id                  13704
alloc_size                8192B
alloc_count               1
alloc_distribution        8KB-16KB 1
alloc_pid                 3725254
stack_info:
0x00000000004007e0        mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
0x0000000000400848        child+0x3c [/opt/testdemo/mem_leak] [mem_leak.c:21]
0x0000ffffaf45ce4c        [unknown] [/usr/lib64/libc.so.6] [unknown]
0x0000ffffaf4c3b0c        [unknown] [/usr/lib64/libc.so.6] [unknown]
Memory Allocate Summary Report-3                        Time:2025/08/18 15:57:23
================================================================================
Top 1 stacks with outstanding allocations:
Top 1 Stack
————————————————————————————————————————————————————————————————————
stack_name                mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
stack_id                  13704
alloc_size                16384B
alloc_count               2
alloc_distribution        8KB-16KB 2
alloc_pid                 3725254
stack_info:
0x00000000004007e0        mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
0x0000000000400848        child+0x3c [/opt/testdemo/mem_leak] [mem_leak.c:21]
0x0000ffffaf45ce4c        [unknown] [/usr/lib64/libc.so.6] [unknown]
0x0000ffffaf4c3b0c        [unknown] [/usr/lib64/libc.so.6] [unknown]
Memory Allocate Summary Report-4                        Time:2025/08/18 15:57:24
================================================================================
Top 1 stacks with outstanding allocations:
Top 1 Stack
————————————————————————————————————————————————————————————————————
stack_name                mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
stack_id                  13704
alloc_size                24576B
alloc_count               3
alloc_distribution        8KB-16KB 3
alloc_pid                 3725254
stack_info:
0x00000000004007e0        mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
0x0000000000400848        child+0x3c [/opt/testdemo/mem_leak] [mem_leak.c:21]
0x0000ffffaf45ce4c        [unknown] [/usr/lib64/libc.so.6] [unknown]
0x0000ffffaf4c3b0c        [unknown] [/usr/lib64/libc.so.6] [unknown]
Memory Allocate Summary Report-5                        Time:2025/08/18 15:57:25
================================================================================
Top 1 stacks with outstanding allocations:
Top 1 Stack
————————————————————————————————————————————————————————————————————
stack_name                mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
stack_id                  13704
alloc_size                32768B
alloc_count               4
alloc_distribution        8KB-16KB 4
alloc_pid                 3725254
stack_info:
0x00000000004007e0        mem_leak+0x1c [/opt/testdemo/mem_leak] [mem_leak.c:9]
0x0000000000400848        child+0x3c [/opt/testdemo/mem_leak] [mem_leak.c:21]
0x0000ffffaf45ce4c        [unknown] [/usr/lib64/libc.so.6] [unknown]
0x0000ffffaf4c3b0c        [unknown] [/usr/lib64/libc.so.6] [unknown]
The report /root/memalloc-20250818-155719.tar is generated successfully.
To view summary report. you can run: devkit report -i /root/memalloc-20250818-155719.tar
To view detail report. you can import the report to the WebUI or IDE to view details.

**Table 2** Parameters in a report file
Parameter	Description
Top 1 stacks with outstanding allocations	Information about top N stacks. Only one stack is displayed in the command output because there is only one stack in the demo.
stack_name	Stack name of the application.
stack_id	Stack ID.
alloc_size	Size of memory that has been allocated but not yet released.
alloc_count	Number of memory allocations.
alloc_distribution	Size and number of memory blocks.
alloc_pid	Process ID.
stack_info	Detailed stack information, including the call stack address, call stack name, module, and code line number.

In the command output, the value of alloc_size increases over time, a memory leak may occur. If "[mem_leak.c:9]" is displayed in the stack_name and stack_info parts, a memory leak occurs in the 9th line of the mem_leak.c file. After making the necessary modifications, you can use the tool to verify whether the issue has been resolved.

You can use the --package parameter to create a TAR package, which can then be imported into the WebUI to view the graphical information.

Parent topic: System Diagnosis