From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751494AbdKTWxV (ORCPT ); Mon, 20 Nov 2017 17:53:21 -0500 Received: from mout.kundenserver.de ([212.227.17.10]:64046 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbdKTWxT (ORCPT ); Mon, 20 Nov 2017 17:53:19 -0500 From: Arnd Bergmann To: Michael Kerrisk Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, John Stultz , Thomas Gleixner , Stephen Boyd , Richard Cochran , Arnd Bergmann Subject: [PATCH] [man-pages] adjtimex.2: document clock_adjtime Date: Mon, 20 Nov 2017 23:53:02 +0100 Message-Id: <20171120225302.3379657-1-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 X-Provags-ID: V03:K0:85RXeWETSU6aR8cx1Iu2RPw86YCJ52Zh1WlaUrQoEOhLhyNM5L4 +RDQpkG9N1dwix047rikmU23VdokRqZkKNmONYsdcEyc7CAdLRrQDMO1pHM2nAVRI5p55DO Ui8pV9zS1VrlGmFTFfJPCGcLzRVGcVN9uMcI5WoI+n9oJlRC08p9OQGsnvC+5j+Ji0KMtrv /X82bfLEEnWFqjUOJUZ/w== X-UI-Out-Filterresults: notjunk:1;V01:K0:k0ekvjofsC0=:+qZmzrJsvc8ncn7tsgU5l1 B7SxaZWVZ4gLRgxeQf8NYiX27pOwM/ZjU8PMxsebY41oFPiA54aq7outUsinTHNeBqIHSBuZj si/J/L+QfBRH67P/n1ENx4alKA2S2WP89SpVlylJuD7M/gMrhmkxuOoQ/21sodhKCkFHy7U5G NB00EkWG8cZxTEtpv1PuuYZa9tuVElmxaXgO5y6yMW3U1jKXe3FajdYmUYR6Blo7j/sTadJTU iKy9uA7nPEpcAK6MLUPese54anhqtboLpNPuH+qBTcVRFyKEhGaKpz6H810T2dhy0xvLAyHoA WCMxaXlnx73q+eI1Ht9E+tpp798Prh/3kBdRZqB3iJQGQYDwJvsiigakyvJIlrCbbP78ig3JA z5f4lnLNsbIXBzM4CNzTOiRxsVY5UMkUgXVefaj+6bxZIVCOVykpUIp10IBInJCH5N03LnEBo aJKUnC8zFSVxraq6asWj1vrN8EfZKVQQzXz3GaK5HDSm3s/W10Il5wvsW7u/b+VOQ9ScVWKgS hiCu7mvck8RjFyWUVpJnmbn03E7ZrEqyI6c3JhcLeaXcqXy0LvATlEp3CgN64KpllcJtinN2S 5KZOETHftpxffThtrDZoT60rPiEn9nu2v5pHBZUO1zTHusUX6nP53TKAjJJdbRJEWzpcePX3c Qx5iWoE8io0bYw+GpDSreVaHKtHkdAsAjN3ULOzLUMx5EliRlwg8VWv01yr5R+CR5ZmthNyil hk2MhRv7qSNjPVWauo2cX1+G9xZq5csIH3RQKw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I was experimenting with some possible changes to adjtimex(2) and clock_adjtime(2) and tried to look up the man page to see what the documented behavior is when I noticed that clock_adjtime() appears to be the only system call that is currently undocumented. Before I do any changes to it, this tries to document what I understand it currently does. Signed-off-by: Arnd Bergmann --- This is my first patch to man-pages, I'm just guessing about what should be in there and how to format it, please reword or reformat as necessary. --- man2/adjtimex.2 | 25 +++++++++++++++++++++++-- man2/clock_adjtime.2 | 1 + 2 files changed, 24 insertions(+), 2 deletions(-) create mode 100644 man2/clock_adjtime.2 diff --git a/man2/adjtimex.2 b/man2/adjtimex.2 index fc6892d..b7c0a5f 100644 --- a/man2/adjtimex.2 +++ b/man2/adjtimex.2 @@ -35,6 +35,8 @@ adjtimex, ntp_adjtime \- tune kernel clock .PP .BI "int adjtimex(struct timex *" "buf" ); .PP +.BI "int clock_adjtimex(clockid_t " clk_id, " struct timex *" "buf" ); +.PP .BI "int ntp_adjtime(struct timex *" buf ); .fi .SH DESCRIPTION @@ -344,6 +346,12 @@ Attempts to set read-only .I status bits are silently ignored. .\" +.SS clock_adjtime () +The +.BR clock_adjtime () +system call (added in Linux 2.6.39) behaves like adjtimex() but takes an additional +.IR clk_id +argument to specify the particular clock on which to act. .SS ntp_adjtime () The .BR ntp_adjtime () @@ -472,6 +480,11 @@ An attempt was made to set to a value other than those listed above. .TP .B EINVAL +The +.I clk_id +specified is not supported on this system. +.TP +.B EINVAL An attempt was made to set .I buf.tick to a value outside the range @@ -482,6 +495,10 @@ where .B HZ is the system timer interrupt frequency. .TP +.B EOPNOTSUPP +.I clk_id +does not support adjustment +.TP .B EPERM .I buf.modes is neither 0 nor @@ -503,10 +520,12 @@ T{ T} Thread safety MT-Safe .TE .SH CONFORMING TO -Neither of these interfaces is described in POSIX.1 +None of these interfaces is described in POSIX.1 .PP .BR adjtimex () -is Linux-specific and should not be used in programs +and +.BR clock_adjtimex () +are Linux-specific and should not be used in programs intended to be portable. .PP The preferred API for the NTP daemon is @@ -533,6 +552,8 @@ is done by the kernel in timer context Thus, it will take one tick into the second for the leap second to be inserted or deleted. .SH SEE ALSO +.BR clock_gettime (2) +.BR clock_settime (2) .BR settimeofday (2), .BR adjtime (3), .BR ntp_gettime (3), diff --git a/man2/clock_adjtime.2 b/man2/clock_adjtime.2 new file mode 100644 index 0000000..b08b9c8 --- /dev/null +++ b/man2/clock_adjtime.2 @@ -0,0 +1 @@ +.so man2/adjtimex.2 -- 2.9.0