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zfs/include/sys/callo.h

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Make file headers conform to ZFS style standard No semantic changes. Change /************\ and \************/ to /* and */ Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-10-04 16:33:43 +00:00
/*
Emulate illumos interface cv_timedwait_hires() Needed for Illumos #3582. This interface is supposed to support a variable-resolution timeout with nanosecond granularity. This implementation rounds up to microsecond resolution, as nanosecond- precision timing is rarely needed for real-world performance tuning and may incur unnecessary busy-waiting. usleep_range() is used if available, otherwise udelay() or msleep() are used depending on the length of the delay interval. Add flags from sys/callo.h as these are used to control the behavior of cv_timedwait_hires(). Specifically, CALLOUT_FLAG_ABSOLUTE Normally, the expiration passed to the timeout API functions is an expiration interval. If this flag is specified, then it is interpreted as the expiration time itself. CALLOUT_FLAG_ROUNDUP Roundup the expiration time to the next resolution boundary. If this flag is not specified, the expiration time is rounded down. References: https://www.illumos.org/issues/3582 illumos/illumos-gate@0689f76 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #304
2013-11-01 20:37:58 +00:00
* Copyright (C) 2007-2013 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
Make file headers conform to ZFS style standard No semantic changes. Change /************\ and \************/ to /* and */ Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
2017-10-04 16:33:43 +00:00
*/
Emulate illumos interface cv_timedwait_hires() Needed for Illumos #3582. This interface is supposed to support a variable-resolution timeout with nanosecond granularity. This implementation rounds up to microsecond resolution, as nanosecond- precision timing is rarely needed for real-world performance tuning and may incur unnecessary busy-waiting. usleep_range() is used if available, otherwise udelay() or msleep() are used depending on the length of the delay interval. Add flags from sys/callo.h as these are used to control the behavior of cv_timedwait_hires(). Specifically, CALLOUT_FLAG_ABSOLUTE Normally, the expiration passed to the timeout API functions is an expiration interval. If this flag is specified, then it is interpreted as the expiration time itself. CALLOUT_FLAG_ROUNDUP Roundup the expiration time to the next resolution boundary. If this flag is not specified, the expiration time is rounded down. References: https://www.illumos.org/issues/3582 illumos/illumos-gate@0689f76 Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #304
2013-11-01 20:37:58 +00:00
#ifndef _SPL_CALLO_H
#define _SPL_CALLO_H
/*
* Callout flags:
*
* CALLOUT_FLAG_ROUNDUP
* Roundup the expiration time to the next resolution boundary.
* If this flag is not specified, the expiration time is rounded down.
* CALLOUT_FLAG_ABSOLUTE
* Normally, the expiration passed to the timeout API functions is an
* expiration interval. If this flag is specified, then it is
* interpreted as the expiration time itself.
* CALLOUT_FLAG_HRESTIME
* Normally, callouts are not affected by changes to system time
* (hrestime). This flag is used to create a callout that is affected
* by system time. If system time changes, these timers must be
* handled in a special way (see callout.c). These are used by condition
* variables and LWP timers that need this behavior.
* CALLOUT_FLAG_32BIT
* Legacy interfaces timeout() and realtime_timeout() pass this flag
* to timeout_generic() to indicate that a 32-bit ID should be allocated.
*/
#define CALLOUT_FLAG_ROUNDUP 0x1
#define CALLOUT_FLAG_ABSOLUTE 0x2
#define CALLOUT_FLAG_HRESTIME 0x4
#define CALLOUT_FLAG_32BIT 0x8
#endif /* _SPL_CALLB_H */