New virHostMemGetTHPSize() is introduced which allows caller to
obtain THP PMD (Page Middle Directory) size, which is equal to
the minimal size that THP can use, taken from kernel doc
(Documentation/admin-guide/mm/transhuge.rst):
Some userspace (such as a test program, or an optimized memory allocation
library) may want to know the size (in bytes) of a transparent hugepage::
cat /sys/kernel/mm/transparent_hugepage/hpage_pmd_size
Since this size depends on the host architecture and the kernel
it won't change whilst libvirtd is running. Therefore, we can use
virOnce() and cache the value. Of course, we can be running under
kernel that has THP disabled or has no notion of THP at all. In
that case a negative value is returned to signal error.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
In all three cases (LXC, QEMU and VBox drivers) the caller has
access to host capabilities and thus know the maximum NUMA node.
This means, that virHostMemAllocPages() doesn't have to query
it. Querying may fail if libvirt was compiled without numactl
support.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
In all three cases (LXC, QEMU and VBox drivers) the caller has
access to host capabilities and thus know the maximum NUMA node.
This means, that virHostMemGetFreePages() doesn't have to query
it. Querying may fail if libvirt was compiled without numactl
support.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Require that all headers are guarded by a symbol named
LIBVIRT_$FILENAME
where $FILENAME is the uppercased filename, with all characters
outside a-z changed into '_'.
Note we do not use a leading __ because that is technically a
namespace reserved for the toolchain.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This introduces a syntax-check script that validates header files use a
common layout:
/*
...copyright header...
*/
<one blank line>
#ifndef SYMBOL
# define SYMBOL
....content....
#endif /* SYMBOL */
For any file ending priv.h, before the #ifndef, we will require a
guard to prevent bogus imports:
#ifndef SYMBOL_ALLOW
# error ....
#endif /* SYMBOL_ALLOW */
<one blank line>
The many mistakes this script identifies are then fixed.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.
In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.
With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to find the
author of a particular bit of code.
This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.
The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Move all APIs with a virHostMEM name prefix out into new
util/virhostmem.h & util/virhostmem.c files
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
