I know that sticky bit performs important role on /tmp directory under Linux to make it writable for anyone in the system while preventing deletion files which created by someone else.
But it seems that we can also set sticky bit on regular files too:
$ chmod +t myprog
$ ls -l myprog
-rw-r--r-t 1 greg users 234239 Feb 6 17:23 myprog
Can we ignore this bit on regular files or is there any role for it?
Sticky bit has a job for executable files (which are also regular files too).
If an executable file has sticky bit on, operating system’s kernel tries to keep this executable in memory after the first run of the executable.
This is an important feature about 20 years ago, when you’re using X terminal and run some big programs from disk or NFS. Stick bit greatly improves loading of the same program again.
But it is not important in today. Modern operating systems already have efficient shared libraries, page caching and virtual memory strategies and we don’t need to specify which program’s text segment must stay in memory anymore. Probably there is no effect of sticky bit on files today, I think kernel just ignore this bit.