mirror_zfs/include/sys/zstd/zstd.h
Sebastian Gottschall 7ce9da0bea do a cyclic seek for unused memory objects in pool
In non regular use cases allocated memory might stay persistent in memory
pool. This small patch checks every minute if there are old objects which
can be released from memory pool.

Right now with regular use, the pool is checked for old objects on each
allocation attempt from this pool. so basically polling by its use. Now
consider what happens if someone writes a lot of files and stops use of
the volume or even unmounts it. So the code will no longer check if
objects can be released from the pool. Already allocated objects will
still stay in pool cache. this is no big issue for common use. But
someone discovered this issue while doing tests. personally i know this
behavior and I'm aware of it. Its no big issue. just a enhancement

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kjeld Schouten-Lebbing <kjeld@schouten-lebbing.nl>
Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Closes #10938
Closes #10969
2020-10-01 12:22:48 -07:00

100 lines
3.2 KiB
C

/*
* BSD 3-Clause New License (https://spdx.org/licenses/BSD-3-Clause.html)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2016-2018, Klara Inc.
* Copyright (c) 2016-2018, Allan Jude
* Copyright (c) 2018-2020, Sebastian Gottschall
* Copyright (c) 2019-2020, Michael Niewöhner
* Copyright (c) 2020, The FreeBSD Foundation [1]
*
* [1] Portions of this software were developed by Allan Jude
* under sponsorship from the FreeBSD Foundation.
*/
#ifndef _ZFS_ZSTD_H
#define _ZFS_ZSTD_H
#ifdef __cplusplus
extern "C" {
#endif
/*
* ZSTD block header
* NOTE: all fields in this header are in big endian order.
*/
typedef struct zfs_zstd_header {
/* Compressed size of data */
uint32_t c_len;
/*
* Version and compression level
* We use a union to be able to big endian encode a single 32 bit
* unsigned integer, but still access the individual bitmasked
* components easily.
*/
union {
uint32_t raw_version_level;
struct {
uint32_t version : 24;
uint8_t level;
};
};
char data[];
} zfs_zstdhdr_t;
/*
* kstat helper macros
*/
#define ZSTDSTAT(stat) (zstd_stats.stat.value.ui64)
#define ZSTDSTAT_INCR(stat, val) \
atomic_add_64(&zstd_stats.stat.value.ui64, (val))
#define ZSTDSTAT_BUMP(stat) ZSTDSTAT_INCR(stat, 1)
/* (de)init for user space / kernel emulation */
int zstd_init(void);
void zstd_fini(void);
size_t zfs_zstd_compress(void *s_start, void *d_start, size_t s_len,
size_t d_len, int level);
int zfs_zstd_get_level(void *s_start, size_t s_len, uint8_t *level);
int zfs_zstd_decompress_level(void *s_start, void *d_start, size_t s_len,
size_t d_len, uint8_t *level);
int zfs_zstd_decompress(void *s_start, void *d_start, size_t s_len,
size_t d_len, int n);
void zfs_zstd_cache_reap_now(void);
#ifdef __cplusplus
}
#endif
#endif /* _ZFS_ZSTD_H */