Instead of having a monolithic 'make install', break it into
multiple targets such as 'make install-man3'. This simplifies
packaging, for example in Debian, where they break this project
into several packages: 'manpages' and 'manpages-dev', each
containing different mandirs.
The above allows for multithread installation: 'make -j'
Also, don't overwrite files that don't need to be overwritten, by
having a target for files, which makes use of make's timestamp
comparison.
This allows for much faster installation times.
For comparison, on my laptop (i7-8850H; 6C/12T):
Old Makefile:
~/src/linux/man-pages$ time sudo make >/dev/null
real 0m7.509s
user 0m5.269s
sys 0m2.614s
The times with the old makefile, varied a lot, between
5 and 10 seconds. The times after applying this patch
are much more consistent. BTW, I compared these times to
the very old Makefile of man-pages-5-09, and those were
around 3.5 s, so it was a bit of my fault to have such a
slow Makefile, when I changed the Makefile some weeks ago.
New Makefile (full clean install):
~/src/linux/man-pages$ time sudo make >/dev/null
real 0m5.160s
user 0m4.326s
sys 0m1.137s
~/src/linux/man-pages$ time sudo make -j2 >/dev/null
real 0m1.602s
user 0m2.529s
sys 0m0.289s
~/src/linux/man-pages$ time sudo make -j >/dev/null
real 0m1.398s
user 0m2.502s
sys 0m0.281s
Here we can see that 'make -j' drops times drastically,
compared to the old monolithic Makefile. Not only that,
but since when we are working with the man pages there
aren't many pages involved, times will be even better.
Here are some times with a single page changed (touched):
New Makefile (one page touched):
~/src/linux/man-pages$ touch man2/membarrier.2
~/src/linux/man-pages$ time sudo make install
- INSTALL /usr/local/share/man/man2/membarrier.2
real 0m0.988s
user 0m0.966s
sys 0m0.025s
~/src/linux/man-pages$ touch man2/membarrier.2
~/src/linux/man-pages$ time sudo make install -j
- INSTALL /usr/local/share/man/man2/membarrier.2
real 0m0.989s
user 0m0.943s
sys 0m0.049s
Also, modify the output of the make install and uninstall commands
so that a line is output for each file or directory that is
installed, similarly to the kernel's Makefile. This doesn't apply
to html targets, which haven't been changed in this commit.
Also, make sure that for each invocation of $(INSTALL_DIR), no
parents are created, (i.e., avoid `mkdir -p` behavior). The GNU
make manual states that it can create race conditions. Instead,
declare as a prerequisite for each directory its parent directory,
and let make resolve the order of creation.
Also, use ':=' instead of '=' to improve performance, by
evaluating each assignment only once.
Ensure than the shell is not called when not needed, by removing
all ";" and quotes in the commands.
See also: <https://stackoverflow.com/q/67862417/6872717>
Specify conventions and rationales used in the Makefile in a comment.
Add copyright.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Document also why each header is required
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This function doesn't use any flags or special types, so there's
no reason to include <asm/unistd.h>; remove it. Add the includes
needed for syscall(2) only.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Also document why each header is needed.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This error can occur if the caller is does not have CAP_IPC_LOCK
and is not a member of the sysctl_hugetlb_shm_group.
Reported-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
As a deprecated feature, it appears that the RLIMIT_MEMLOCK
can also be used to permit huge page allocation, but let's
not document that for now.
In the Linux 5.12, see fs/hugetlbfs/inode.c.
static int can_do_hugetlb_shm(void)
{
kgid_t shm_group;
shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
}
...
struct file *hugetlb_file_setup(const char *name, size_t size,
vm_flags_t acctflag, struct user_struct **user,
int creat_flags, int page_size_log)
{
...
if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
*user = current_user();
if (user_shm_lock(size, *user)) {
task_lock(current);
pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
current->comm, current->pid);
task_unlock(current);
} else {
*user = NULL;
return ERR_PTR(-EPERM);
}
}
...
}
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The installation path was changed recently (See 'prefix' in the
Makefile). I forgot to update the README with those changes.
Fix it.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Explain also why headers are needed.
And some ffix.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
It is only used for providing 'sigset_t'. We're only documenting
(with some exceptions) the includes needed for constants and the
prototype itself. And 'sigset_t' is better documented in
system_data_types(7). Remove that include.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
All of the constants used by mknod() are defined in <sys/stat.h>.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
AFAICS, there's no use for <unistd.h> here. The prototype is
declared in <sys/mman.h>, and there are no constants needed.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Remove the libkeyutils prototype from the synopsis, which isn't
documented in the rest of the page, and as NOTES says, it's
probably better to use the various library functions.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Alejandro Colomar