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17497 Commits

Author SHA1 Message Date
Michael Kerrisk 55e04d2370 bzero.3: Document explicit_bzero() (new in glibc 2.25) 
Also, reword the description of bzero somewhat.

By now, over time, I've completely rewritten the page,
so change the copyright as well.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-02-02 08:25:18 +13:00
Michael Kerrisk 879091c911 bcmp.3, bcopy.3, bzero.3, memccpy.3, memchr.3, memcmp.3, memcpy.3, memfrob.3, memmem.3, memmove.3, memset.3: SEE ALSO: add bstring(3) 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-02-02 08:25:18 +13:00
Michael Kerrisk 2cbb6fb4e9 getrandom.2: Starting with glibc 2.25, getrandom() is now declared in <sys/random.h> 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-02-02 08:25:18 +13:00
Michael Kerrisk 089527aabd core.5: Reorder a bullet list 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 11:39:30 +13:00
Michael Kerrisk 9d8b225095 core.5: Clarify that dumping program's initial CWD is root directory 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 11:30:03 +13:00
Michael Kerrisk 1c3aae54d2 core.5: wfix 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 11:24:14 +13:00
Michael Kerrisk aee4257750 core.5: The target of core dump piping can also be a script 
Verified by experiment.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 10:46:25 +13:00
Jakub Wilk 5465ae9568 futex.2, open_by_handle_at.2, seccomp.2, socket.2, console_codes.4, protocols.5, aio.7, capabilities.7, libc.7, netlink.7, raw.7, standards.7, unicode.7, uri.7, vdso.7: tfix 
Escape hyphens in URLs.

Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 08:33:49 +13:00
Jakub Wilk ff391afb77 man-pages.7: tfix 
Escape hyphens when explaining how to escape hyphens.

Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-30 08:33:24 +13:00
Erik Kline 768b58c715 getenv.3: wfix 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-27 08:45:31 +13:00
Jakub Wilk bb1639a237 mlock.2: tfix 
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-27 08:41:57 +13:00
Jakub Wilk 3a9b4c11e8 mlock.2: tfix 
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-27 08:14:37 +13:00
Michael Kerrisk 3bd859bfaf mmap.2: mincore(2) can be used to discover which pages of a mapping are resident 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 17:09:25 +13:00
Michael Kerrisk a8db50d35a madvise.2: Note that madvise() is generally about improving performance 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:51:32 +13:00
Michael Kerrisk 268612340a posix_fadvise.2: srcfix 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk ba759b3c39 posix_fadvise.2: One can use open(2) + mmap(2) + mincore(2) as a 'fincore' 
Note that open(2) + mmap(2) + mincore(2) to get a view of which
pages of a file are currently cached.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk 38ca12203c posix_fadvise.2: Mention /proc/sys/vm/drop_caches 
It may be helpful for the reader of this page to know about
/proc/sys/vm/drop_caches.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk 6f22eabf14 mincore.2: SEE ALSO: add madvise(2), posix_fadvise(2), posix_madvise(3) 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk 15ef1edc77 mlock.2: SEE ALSO: add mincore(2) 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk 7ba63e47a6 fsync.2: SEE ALSO: add posix_fadvise(2) 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:42 +13:00
Michael Kerrisk 250d41b91b posix_fadvise.2: SEE ALSO: mincore(2) 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:21:41 +13:00
Michael Kerrisk f90b94e32c posix_fadvise.2: Note that POSIX_FADV_DONTNEED *may* try to write back dirty pages 
Looking at the code in mm/fadvise.c, we have

    case POSIX_FADV_DONTNEED:
        if (!inode_write_congested(mapping->host))
            __filemap_fdatawrite_range(mapping, offset, endbyte,
                                       WB_SYNC_NONE);

This suggests that *if* the backing device is not congested, then
__filemap_fdatawrite_range() is called. The comments for that
function say:

    __filemap_fdatawrite_range - start writeback on mapping dirty pages in range

So, my reading of this is that *maybe* some dirty pages will be
written to the backing device by the time that POSIX_FADV_DONTNEED
gets to calling invalidate_mapping_pages() whose description says:

/**
 * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
 * @mapping: the address_space which holds the pages to invalidate
 * @start: the offset 'from' which to invalidate
 * @end: the offset 'to' which to invalidate (inclusive)
 *
 * This function only removes the unlocked pages, if you want to
 * remove all the pages of one inode, you must call truncate_inode_pages.
 *
 * invalidate_mapping_pages() will not block on IO activity. It will not
 * invalidate pages which are dirty, locked, under writeback or mapped into
 * pagetables.
 */

So, my reading of this is that the handling of dirty pages is an
optimization. If some pages can be written in time, they will be
freed by POSIX_MADV_DONTFREE. But there are no guarantees.

All of that said, some experimentation suggests that, in a lot
of cases, POSIX_MADV_DONTFREE does often free dirty pages.

See https://bugzilla.kernel.org/show_bug.cgi?id=95421.

Reported-by: Maik Zumstrull <maik@zumstrull.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 16:20:45 +13:00
Michael Kerrisk a6b80261c8 posix_fadvise.2: Reorganize some text 
Details for various flags were hidden under NOTES.
Move them to DESCRIPTION, to make the details more
obvious.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 15:03:17 +13:00
Michael Kerrisk dfbb4842f9 write.2: Alert the reader that there is a limit on 'count' 
See https://bugzilla.kernel.org/show_bug.cgi?id=86061

Reported-by: Kai NODA <nodakai@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 15:03:17 +13:00
Michael Kerrisk 6435869d7e read.2: Rework text in DESCRIPTION that talks about limits for 'count' 
See https://bugzilla.kernel.org/show_bug.cgi?id=86061

Reported-by: Kai NODA <nodakai@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 15:03:11 +13:00
Michael Kerrisk 68210340d4 open.2: Clarify distinction between file creation flags and file status flags 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk 7fba006583 open.2: Restructure O_NOFOLLOW text for easier parsing 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk 6ccb7137eb open.2: Note ambiguity of ELOOP error when using O_NOFOLLOW 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk 8db11e238b open.2: Clarify that O_NOFOLLOW is now in POSIX 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk dc951c848d truncate.2: Note use of ftruncate() for POSIX shared memory objects 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk b59a4ee7bf scanf.3: Document the quote (') modifier for decimal conversions 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk 2b609f22c4 printf.3: Add references to setlocale(3) in discussions of locales 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 14:53:33 +13:00
Michael Kerrisk 5d717bda58 printf.3: As a nonstandard extension, GNU treats 'll' and 'L' as synonyms 
See https://bugzilla.kernel.org/show_bug.cgi?id=190341.

Reported-by: Nadav Har'El  <nyh@math.technion.ac.il>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:41:48 +13:00
Michael Kerrisk 1b8d305469 printf.3: Document nonstandard 'Z' modifier 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:20:50 +13:00
Michael Kerrisk 74b9e29f92 printf.3: Document 'q' length modifier 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:20:50 +13:00
Jakub Wilk 2e621720d0 iconv.1: ffix 
Don't embolden commas between option names.

Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:31 +13:00
Jakub Wilk 2081060818 iconv.1: tfix 
Escape hyphens in option names and pathnames.

Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:31 +13:00
Jakub Wilk 908a1b280a proc.5: tfix 
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:31 +13:00
Jakub Wilk 555b5c7b1b vfork.2: tfix 
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:31 +13:00
Jakub Wilk ba71223dfb ioctl_iflags.2: tfix 
Signed-off-by: Jakub Wilk <jwilk@jwilk.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:30 +13:00
Michael Kerrisk e00916fdee random_r.3: tfix 
Reported-by: Jan Ziak <0xe2.0x9a.0x9b@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:30 +13:00
Michael Kerrisk 6e9219f775 capabilities.7: Further enhance the recommendation against new uses of CAP_SYS_ADMIN 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:30 +13:00
Michael Kerrisk fa50d3d48b capabilities.7: Explicitly point from CAP_SYS_ADMIN to "Notes for kernel developers" 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-26 09:10:24 +13:00
Michael Kerrisk ddb624a9e5 capabilities.7: Improvements after feedback from Casey Schaufler 
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 17:04:44 +13:00
Michael Kerrisk 8de5616fd7 capabilities.7: Add subsection with notes to kernel developers 
Provide some notes to kernel developers considering how to choose
which capability should govern a new kernel feature.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 17:04:07 +13:00
Michael Kerrisk 5a5bde703f proc.5: Add reference to slabinfo(5) in discussion of /proc/meminfo 'Slab' field 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 16:57:08 +13:00
Tadeusz Struk 58b9f0ebb9 readdir.3: tfix 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 13:09:18 +13:00
Michael Kerrisk accc82d2d4 getopt.3: Correct details of use of <stdio.h> to get getopt() declaration 
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 11:41:51 +13:00
Michael Kerrisk a4746c3978 getopt.3: Reword discussion of error handling and reporting 
The existing description was hard to understand. Break
it into a bullet list that separates out the details
in a manner that is easier to parse.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 10:29:14 +13:00
Michael Kerrisk 797438e749 getopt.3: Remove redundant text 
The same information is described in two consecutive paragraphs.
Remove the shorter paragraph, leaving the longer one that
contains more information.

Reported-by: John Wiersba <jrw32982@yahoo.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
 2017-01-25 10:04:27 +13:00