Hello Claudio, Thanks for your patch! On 04/18/2018 11:39 AM, Claudio Scordino wrote: > This patch documents two additional flags recently introduced for the > sched_flags field of sched_setattr(). > These flags are namely SCHED_FLAG_RECLAIM [1] and SCHED_FLAG_DL_OVERRUN [2]. > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ccc9d651a7d26fec88d2375c4dd4e097cc0f8de7 > [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=34be39305a77b8b1ec9f279163c7cdb6cc719b91 > > Signed-off-by: Claudio Scordino <claudio@xxxxxxxxxxxxxxx> > --- > man2/sched_setattr.2 | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/man2/sched_setattr.2 b/man2/sched_setattr.2 > index 492ccbc..54bf6e8 100644 > --- a/man2/sched_setattr.2 > +++ b/man2/sched_setattr.2 > @@ -150,15 +150,27 @@ This field specifies the scheduling policy, as one of the > values listed above. > .TP > .I sched_flags > -This field contains flags controlling scheduling behavior. > -Only one such flag is currently defined: > -.BR SCHED_FLAG_RESET_ON_FORK . > -As a result of including this flag, children created by > +This field contains flags controlling the scheduling behavior. > +.IP > +.BR SCHED_FLAG_RESET_ON_FORK : > +children created by > .BR fork (2) > do not inherit privileged scheduling policies. > See > .BR sched (7) > for details. > +.IP > +.BR SCHED_FLAG_RECLAIM : > +allows a > +.BR SCHED_DEADLINE > +task to reclaim bandwidth unused by other real-time tasks through the GRUB > +algorithm. Available since kernel 4.13. Of course, the above leaves the reader asking "what is the GRUB algorithm"? What should we say about this? Or should the text somehow be worded more specifically to avoid mentioning a specific algorith? > +.IP > +.BR SCHED_FLAG_DL_OVERRUN : > +allows a > +.BR SCHED_DEADLINE > +task to get informed about runtime overruns through the delivery of SIGXCPU > +signals. Available since kernel 4.16. I've reworked this piece as: SCHED_FLAG_DL_OVERRUN (since Linux 4.16) This flag allows a SCHED_DEADLINE to get informed about run-time overruns, which may be caused by (for example) coarse execution time accounting or incor‐ rect parameter assignment. Notification takes the form of a SIGXCPU signal which is generated on each overrun. But, I have some questions. 1. The text on coarse execution and incorrect parameter assignment comes from the mail message that was referred to by commit 34be39305a77b8b1ec9f279163c7cdb6cc719b91: https://lkml.org/lkml/2009/10/16/170 Is that added text in the man page okay? 2. Possibly, I am misreading the code, but the SIGXCPU signal appears to be a process-directed signal, rather than a thread-directed signal? Am I correct, and if so, is that really the desired behavior? Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- 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
