Package: libc6
Version: 2.19, 2.24, 2.28
Severity: normal
--- Please enter the report below this line. ---
Initial condition of the problem representing is a program in the
single source code, built on-and for Debian 7, 8, 9, 10 with a
result in the Live disks.
The program represents a web-interface of several pages, where here used only the first page.
In building the first page there used wide range of memory chunks: small objects of the C++ classes (~100 bytes), resources of the image files (~10 kbytes), GD memory blocks (~1 kbytes), so on
The live disks were started under VirtualBox 5.2, where the got
data was measured by top.
The data measuring under VirtualBox performed into the next
stages:
1. Start the program and set the initial state, fixing the memory
allocation — measuring the initial memory consumption value
2. Perform the allocation-freeing iteration
2.1. Open the first Web-interface page from a Web-browser of the
host system
2.2. Close the page on the Web-browser
2.3. Wait to close-freeing session of the first Web-interface page
on the program side, 1 minute — measuring the iteration memory
consumption value
3. Return to the stage 2 and repeating 5 iterations
The stage 2.3 tested to real freeing all the allocated memory
blocks both by the objects counters and by valgrind!
In the result we have next data:
| Environment | Initially, MB | Iter. 1, MB | Iter. 2, MB | Iter. 3, MB | Iter. 4, MB | Iter. 5, MB | Resume |
|---|---|---|---|---|---|---|---|
| Debian 10 amd64, GLibC 2.28, GCC 8.3.0 | 182 | 191.5 | 199 | 206 | 212 | 212 | Satiated on the iteration 4, base consumption 9.5 MB, extra consumption 20 MB (200 %), liboscada.so 3.5 MB, ui_WebVision.so 0.74 MB |
| Debian 9 amd64, GLibC 2.24, GCC 6.3.0 | 160 | 170 | 178 | 179 | 183 | 185 | Satiated on the iteration 5, base consumption 10 MB, extra consumption 15 MB (150 %), liboscada.so 3.5 MB, ui_WebVision.so 0.72 MB |
| Debian 8 amd64, GLibC 2.19, GCC 4.9.2 | 125.5 | 133 | 139 | 139 | 139 | 139 | Satiated on the iteration 2, base consumption 7.5 MB, extra consumption 6 MB (80 %), liboscada.so 3.8 MB, ui_WebVision.so 0.79 MB |
| Debian 7 amd64, GLibC 2.13, GCC 4.7.2 | 101 | 108 | 111 | 112 | 112 | 112 | Satiated on the iteration 2, base consumption 7 MB, extra consumption 4 MB (57 %), liboscada.so 3.4 MB, ui_WebVision.so 0.85 MB |
| Debian 10 i386, GLibC 2.28, GCC 8.3.0 | 151 | 158 | 162.5 | 166 | 166 | 166 | Satiated on the iteration 3, base consumption 7 MB, extra consumption 8 MB (114 %), liboscada.so 3.7 MB, ui_WebVision.so 0.9 MB |
| Debian 9 i386, GLibC 2.24, GCC 6.3.0 | 125 | 131 | 132 | 136 | 136 | 139 | Satiated on the iteration 5, base consumption 6 MB, extra consumption 8 MB (133 %), liboscada.so 3.7 MB, ui_WebVision.so 0.9 MB |
| Debian 8 i386, GLibC 2.19, GCC 4.9.2 | 92.5 | 99 | 101.5 | 103 | 103.5 | 103.5 | Satiated on the iteration 2, base consumption 6.5 MB, extra consumption 4.5 (69 %), liboscada.so 3.6 MB, ui_WebVision.so 0.94 MB |
| Debian 7 i386, GLibC 2.13, GCC 4.7.2 | 70 | 76 | 76 | 76 | 77 | 77 | Satiated on the iteration 2, base consumption 6 MB, extra consumption 1 MB (16 %), liboscada.so 3.6 MB, ui_WebVision.so 0.9 MB |
| ALTLinux 6 i386, GLibC 2.11.3, GCC 4.5.4 | 69 | 74 | 75 | 75 | 75 | 75 | Satiated on the iteration 2, base consumption 5 MB, extra consumption 1 MB (20 %), liboscada.so 2.3 MB, ui_WebVision.so 0.9 MB |
From the data we have the memory effectivity on AMD64 and I386 platform:
and the absolute
initial size for the both platform:
I know about "the Memory Allocation Tunables" (https://www.gnu.org/software/libc/manual/html_node/Memory-Allocation-Tunables.html)
and have tried them but:
- I have not got any effect from environments like to
"GLIBC_TUNABLES=glibc.malloc.trim_threshold=128" on Debian 10
- If the tunables real work, why their do not apply globally (on
the system level) to return the memory effectivity to the level of
the Debian 7 (GLibC 2.13)?
- If the new memory allocator (into GLibC 2.28) is so good, how
can I return its memory effectivity to the level of the Debian 7
(GLibC 2.13)?
The tested program and the analyse page provided on the page http://oscada.org/wiki/Modules/WebVision#Efficiency
--- System information. ---
Architecture:
Kernel: Any for i386, amd64
Debian Release: 8, 9, 10
500 stable-updates ftp.ua.debian.org
500 stable security.debian.org
500 stable ftp.ua.debian.org
--- Package information. ---
Package's Depends field is empty.
Package's Recommends field is empty.
Package's Suggests field is empty.