Here's an updated version of [David Ahern's] patch that
expands the "mmap" definition as well as that of "mmap_data".
Also some manpage related formatting improvements from the
original patch.
Link: https://lkml.org/lkml/2013/11/11/505
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch attempts to clarify the pid and cpu options to
perf_event_open().
It does two things:
1. Tries to make clear that the "pid" argument can mean
process *or* thread. This is made confusing by
how Linux uses the terms mostly interchangeably.
2. The cpu/pid documentation was confusing because of
how the parameters are interdependent. Since there
are only 6 possible combinations I broke out the
possibilities into a table.
Reported-by: Manuel Selva <selva.manuel@gmail.com>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
events==0 does not mean that revents is always returned as
zero. The "output only" events (POLLHUP, POLLERR, POLLNVAL)
can still be returned.
See https://bugzilla.kernel.org/show_bug.cgi?id=61911
Reported-by: Paolo Bonzini <bonzini@gnu.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
See https://bugzilla.kernel.org/show_bug.cgi?id=42705
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
It turns out that the perf_event mmap page rdpmc/time setting was
broken, dating back to the introduction of the feature. Due
to a mistake with a bitfield, two different values mapped to
the same feature bit.
A new somewhat backwards compatible interface was introduced
in Linux 3.12. A much longer report on the issue can be found
here:
https://lwn.net/Articles/567894/
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A new perf_event related ioctl, PERF_EVENT_IOC_ID, was added
in Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A new PERF_SAMPLE_IDENTIFIER sample type was added in Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Support for the PERF_COUNT_SW_DUMMY event type was added in
Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
fallocate() zeroes only space that did not previously contain
data, but leaves existing data untouched.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The PERF_EVENT_IOC_PERIOD ioctl was broken until 2.6.36,
and it turns out that the ARM architecture has some
differing behavior too.
Reported-by: Andreas Sandberg <andreas.sandberg@it.uu.se>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The following documents the E2BIG error return for
perf_event_open().
I actually ran into this error the hard way and it took me
half a day to figure out why my ->size value was changing.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
When I asked to webmaster@kernel.org, Konstantin Ryabitsev
answered that the ".nl." is "an obsolete scheme and really
should be changed to just ftp.kernel.org".
Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The existing text describes the timestamp fields as 'time_t'
and delegates discussion of nanosecond timestamps under NOTES.
Nanosecond timestamps have been around for a while now,
and are in POSIX.1-2008, so reverse the orientation of the
discussion, putting the nanosecond fields into DESCRIPTION
and detailing the historical situation under NOTES.
Reported-by: Yang Yang <yangyang.gnu@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This started out as just adding the new perf_event_open features
from Linux 3.11 (which was the addition of transactional memory
defines for PERF_SAMPLE_BRANCH_STACK samples) but turned into a
general cleanup of the PERF_SAMPLE_BRANCH_STACK documentation.
The main clarification is that at least one of the non-privilege values
must be set or else perf_event_open will return an EINVAL error.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Note that NFS versions since version 3 support an "access" call
so that the client doesn't have to guess permissions or ID
mapping on its own.
(See RFC 1813 sections 1.7 and 3.3.4.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk