This patch adds documentation for the new prctl option to disable transparent hugepages on a per-mm_struct basis. The patch that implements this functionality can be found here: http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg595756.html (Note that the patch hasn't made it through into the community kernel, yet. I'm submitting the documentation ahead of time to make sure that everything is in order if/when the patch makes it into the kernel.) Please let me know if you notice anything that should be changed or added. Thanks! Signed-off-by: Alex Thorlton <athorlton@xxxxxxx> Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@xxxxxxxxx> --- man2/prctl.2 | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/man2/prctl.2 b/man2/prctl.2 index 70636e5..1588064 100644 --- a/man2/prctl.2 +++ b/man2/prctl.2 @@ -773,6 +773,23 @@ option. .\" symbolic-link transitions over all process running in a system. .\" ========== END FIXME .RE +.TP +.BR PR_SET_THP_DISABLED " (since Linux 3.14)" +If +.IR arg2 +is nonzero, set the "disable transparent hugepages" attribute of the calling process. +Hugepages are disabled by manipulating the +.BR VM_NOHUGEPAGE +flag in +.I def_flags +of a process's +.IR mm_struct . +This flag is carried down from the parent's +.IR mm_struct +on fork. +.TP +.BR PR_GET_THP_DISABLED " (since Linux 3.14)" +Returns (as the function result) the state of the "disable transparent hugepages" attribute of the calling process. The result will be 1 if the attribute is set and 0 otherwise. .\" .SH RETURN VALUE On success, @@ -783,6 +800,7 @@ On success, .BR PR_GET_TIMING , .BR PR_GET_SECUREBITS , .BR PR_MCE_KILL_GET , +.BR PR_GET_THP_DISABLED , and (if it returns) .BR PR_GET_SECCOMP return the nonnegative values described above. @@ -806,11 +824,12 @@ is not recognized. .B EINVAL .I option is -.BR PR_MCE_KILL -or -.BR PR_MCE_KILL_GET -or +.BR PR_MCE_KILL , +.BR PR_MCE_KILL_GET , .BR PR_SET_MM , +.BR PR_SET_THP_DISABLE +or +.BR PR_GET_THP_DISABLE , and unused .BR prctl () arguments were not specified as zero. -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
