71bd934101
Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...
130 lines
3.8 KiB
C
130 lines
3.8 KiB
C
/*
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* Compressed RAM block device
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*
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* Copyright (C) 2008, 2009, 2010 Nitin Gupta
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* 2012, 2013 Minchan Kim
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*
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* This code is released using a dual license strategy: BSD/GPL
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* You can choose the licence that better fits your requirements.
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*
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* Released under the terms of 3-clause BSD License
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* Released under the terms of GNU General Public License Version 2.0
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*
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*/
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#ifndef _ZRAM_DRV_H_
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#define _ZRAM_DRV_H_
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#include <linux/rwsem.h>
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#include <linux/zsmalloc.h>
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#include <linux/crypto.h>
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#include "zcomp.h"
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#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
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#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT)
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#define ZRAM_LOGICAL_BLOCK_SHIFT 12
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#define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT)
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#define ZRAM_SECTOR_PER_LOGICAL_BLOCK \
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(1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT))
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/*
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* The lower ZRAM_FLAG_SHIFT bits of table.flags is for
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* object size (excluding header), the higher bits is for
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* zram_pageflags.
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*
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* zram is mainly used for memory efficiency so we want to keep memory
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* footprint small so we can squeeze size and flags into a field.
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* The lower ZRAM_FLAG_SHIFT bits is for object size (excluding header),
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* the higher bits is for zram_pageflags.
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*/
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#define ZRAM_FLAG_SHIFT 24
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/* Flags for zram pages (table[page_no].flags) */
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enum zram_pageflags {
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/* zram slot is locked */
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ZRAM_LOCK = ZRAM_FLAG_SHIFT,
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ZRAM_SAME, /* Page consists the same element */
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ZRAM_WB, /* page is stored on backing_device */
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ZRAM_UNDER_WB, /* page is under writeback */
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ZRAM_HUGE, /* Incompressible page */
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ZRAM_IDLE, /* not accessed page since last idle marking */
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__NR_ZRAM_PAGEFLAGS,
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};
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/*-- Data structures */
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/* Allocated for each disk page */
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struct zram_table_entry {
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union {
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unsigned long handle;
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unsigned long element;
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};
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unsigned long flags;
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#ifdef CONFIG_ZRAM_MEMORY_TRACKING
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ktime_t ac_time;
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#endif
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};
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struct zram_stats {
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atomic64_t compr_data_size; /* compressed size of pages stored */
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atomic64_t num_reads; /* failed + successful */
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atomic64_t num_writes; /* --do-- */
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atomic64_t failed_reads; /* can happen when memory is too low */
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atomic64_t failed_writes; /* can happen when memory is too low */
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atomic64_t invalid_io; /* non-page-aligned I/O requests */
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atomic64_t notify_free; /* no. of swap slot free notifications */
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atomic64_t same_pages; /* no. of same element filled pages */
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atomic64_t huge_pages; /* no. of huge pages */
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atomic64_t huge_pages_since; /* no. of huge pages since zram set up */
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atomic64_t pages_stored; /* no. of pages currently stored */
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atomic_long_t max_used_pages; /* no. of maximum pages stored */
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atomic64_t writestall; /* no. of write slow paths */
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atomic64_t miss_free; /* no. of missed free */
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#ifdef CONFIG_ZRAM_WRITEBACK
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atomic64_t bd_count; /* no. of pages in backing device */
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atomic64_t bd_reads; /* no. of reads from backing device */
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atomic64_t bd_writes; /* no. of writes from backing device */
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#endif
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};
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struct zram {
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struct zram_table_entry *table;
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struct zs_pool *mem_pool;
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struct zcomp *comp;
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struct gendisk *disk;
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/* Prevent concurrent execution of device init */
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struct rw_semaphore init_lock;
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/*
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* the number of pages zram can consume for storing compressed data
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*/
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unsigned long limit_pages;
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struct zram_stats stats;
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/*
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* This is the limit on amount of *uncompressed* worth of data
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* we can store in a disk.
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*/
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u64 disksize; /* bytes */
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char compressor[CRYPTO_MAX_ALG_NAME];
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/*
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* zram is claimed so open request will be failed
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*/
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bool claim; /* Protected by disk->open_mutex */
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#ifdef CONFIG_ZRAM_WRITEBACK
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struct file *backing_dev;
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spinlock_t wb_limit_lock;
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bool wb_limit_enable;
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u64 bd_wb_limit;
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struct block_device *bdev;
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unsigned long *bitmap;
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unsigned long nr_pages;
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#endif
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#ifdef CONFIG_ZRAM_MEMORY_TRACKING
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struct dentry *debugfs_dir;
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#endif
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};
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#endif
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