IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
The current implementation of time64_to_tm() contains unnecessary loops,
branches and look-up tables. The new one uses an arithmetic-based algorithm
appeared in [1] and is approximately 3x faster (YMMV).
The drawback is that the new code isn't intuitive and contains many 'magic
numbers' (not unusual for this type of algorithm). However, [1] justifies
all those numbers and, given this function's history, the code is unlikely
to need much maintenance, if any at all.
Add a KUnit test for it which checks every day in a 160,000 years interval
centered at 1970-01-01 against the expected result.
[1] Neri, Schneider, "Euclidean Affine Functions and Applications to
Calendar Algorithms". https://arxiv.org/abs/2102.06959
Signed-off-by: Cassio Neri <cassio.neri@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210622213616.313046-1-cassio.neri@gmail.com
Address these kernel-doc warnings:
kernel/time/timeconv.c:79: warning: Function parameter or member
'totalsecs' not described in 'time64_to_tm'
kernel/time/timeconv.c:79: warning: Function parameter or member
'offset' not described in 'time64_to_tm'
kernel/time/timeconv.c:79: warning: Function parameter or member
'result' not described in 'time64_to_tm'
The parameters are described but lack colons after the parameter name.
[ tglx: Massaged changelog ]
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1605252275-63652-1-git-send-email-alex.shi@linux.alibaba.com
time_to_tm() takes time_t as an argument.
time_t is not y2038 safe.
Add time64_to_tm() that takes time64_t as an argument
which is y2038 safe.
The plan is to eventually replace all calls to time_to_tm()
by time64_to_tm().
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
There are many similar code in kernel for one object: convert time between
calendar time and broken-down time.
Here is some source I found:
fs/ncpfs/dir.c
fs/smbfs/proc.c
fs/fat/misc.c
fs/udf/udftime.c
fs/cifs/netmisc.c
net/netfilter/xt_time.c
drivers/scsi/ips.c
drivers/input/misc/hp_sdc_rtc.c
drivers/rtc/rtc-lib.c
arch/ia64/hp/sim/boot/fw-emu.c
arch/m68k/mac/misc.c
arch/powerpc/kernel/time.c
arch/parisc/include/asm/rtc.h
...
We can make a common function for this type of conversion, At least we
can get following benefit:
1: Make kernel simple and unify
2: Easy to fix bug in converting code
3: Reduce clone of code in future
For example, I'm trying to make ftrace display walltime,
this patch will make me easy.
This code is based on code from glibc-2.6
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
