Hi!
A year ago, I wrote a small mlockall()-wrapper ("noswap") to make
certain programs unswappable. It used to work perfectly, until I
upgraded to kernel 2.6.x (2.6.13.1 in my case, but that shouldn't
matter), which made the mlockall() execute without error, but also
without any effect (the "L" in the STAT column of "ps axf" which
indicates locked pages is missing).
The complete program source and the strace log of
strace -v -f -s 4096 noswap sleep 9999
is here:
http://marc-jano.de/tmp/noswap-10935/
Here are the most important lines:
-----< snip >-----
/* mark process as unswappable for all times */
if (ret = mlockall (MCL_CURRENT | MCL_FUTURE))
perror ("mlockall()");
/* give up root privileges */
if (ret = setuid (getuid()) ) { perror ("setuid()"); exit (ret); };
if (ret = setgid (getgid()) ) { perror ("setgid()"); exit (ret); };
/* execute program */
if (ret = execvp (argv[1], exec_argv)) perror ("execvp()");
exit (ret);
-----< snip >-----
The strace log shows that mlockall() returns with no error.
If I replace the execvp() call with a sleep(9999), then the current
process (noswap) is properly locked, as can be checked by looking
for a capital "L" in the ps STAT column.
So it seems that the mlockall() flags are not passed somehow when
using execvp().
Best regards
Marc-Jano (not subscribed to the list, so for further questions,
please Cc:)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
