Copy-on-write: Difference between revisions

Revision as of 23:09, 16 June 2022

Revision as of 10:52, 30 July 2022

Line 15:

Loading the libraries for an application is also a use of copy-on-write technique. The dynamic linker maps libraries as private like follows. Any writing action on the libraries will trigger a COW in virtual memory management.

<syntaxhighlight lang="c">

openatopen(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3

mmap(NULL, 3906144, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0)

mmap(0x7f8a3ced4000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b0000)