config.h

#ifndef _HK_CONFIG_H_
#define _HK_CONFIG_H_

#define HUNTER_SUPER_MAGIC 0x48554E54

/*
 * The HUNTER filesystem constants/structures
 */

/*
 * Mount flags
 */
#define HUNTER_MOUNT_PROTECT      0x000001 /* wprotect CR0.WP */
#define HUNTER_MOUNT_XATTR_USER   0x000002 /* Extended user attributes */
#define HUNTER_MOUNT_POSIX_ACL    0x000004 /* POSIX Access Control Lists */
#define HUNTER_MOUNT_DAX          0x000008 /* Direct Access */
#define HUNTER_MOUNT_ERRORS_CONT  0x000010 /* Continue on errors */
#define HUNTER_MOUNT_ERRORS_RO    0x000020 /* Remount fs ro on errors */
#define HUNTER_MOUNT_ERRORS_PANIC 0x000040 /* Panic on errors */
#define HUNTER_MOUNT_HUGEMMAP     0x000080 /* Huge mappings with mmap */
#define HUNTER_MOUNT_HUGEIOREMAP  0x000100 /* Huge mappings with ioremap */
#define HUNTER_MOUNT_FORMAT       0x000200 /* was FS formatted on mount? */
#define HUNTER_MOUNT_DATA_COW     0x000400 /* Copy-on-write for data integrity */

/*
 * Maximal count of links to a file
 */
#define HK_LINK_MAX 32000

#define POSSIBLE_MAX_CPU 1024

#define HK_MAX_LAYOUTS 64

#define PM_ACCESS_GRANU 256

/*
 * HUNTER CONFIGURATIONS
 */
#define HK_PBLK_SZ            PAGE_SIZE
#define HK_LBLK_SZ            PAGE_SIZE /* logic block size */
#define HK_NUM_INO            (2 * 1024 * 1024) /* extend to 2M files */
#define HK_ATTRLOG_SLOTS      HK_NUM_INO /* one-to-one mapping */
#define HK_ATTRLOG_ENTY_SLOTS (4)
#define HK_LINIX_SLOTS        (1024 * 256) /* related to init size */
#define HK_HISTORY_WINDOWS    (1)          /* for dynamic workloads */
#define HK_NAME_LEN           99
#define HK_HASH_BITS          6  /* for directory table */
#define HK_CMT_QUEUE_BITS     10 /* for commit queue */
#define HK_CMT_WORKER_NUM     4  /* for commit worker */
#define HK_JOURNAL_SIZE       (4 * 1024)
#define HK_PERCORE_JSLOTS     (1) /* per core journal slots */
#define HK_BLKS_SIZE(blks)    (((blks) << 12) + ((blks) << 6))
#define HK_CMT_BATCH_NUM      (2 * 1024 * 1024)
#define HK_CHECKPOINT_TIME_INTERNAL 3 /* seconds */

/* ======================= Control by Makefile ======================= */
/* enable background commit system */
#if HK_ENABLE_ASYNC == 1
#define CONFIG_CMT_BACKGROUND

#ifdef HK_CHECKPOINT_INTERVAL
#define HK_CMT_TIME_GAP HK_CHECKPOINT_TIME_INTERNAL
#else
#define HK_CMT_TIME_GAP HK_CHECKPOINT_TIME_INTERNAL
#endif

#endif

/* enable dynamic workload detection */
#if HK_ENABLE_IDX_ALLOC_PREDICT == 1
#define CONFIG_DYNAMIC_WORKLOAD 
#endif

/* enable pure log-structured file system */
#if HK_ENABLE_LFS == 1 
#define CONFIG_LAYOUT_TIGHT
#define HK_PBLK_SZ          (PAGE_SIZE + sizeof(struct hk_header))
#define HK_NEXT_PADDR(addr) addr += HK_PBLK_SZ
#endif

/* ======================= Write ordering ========================= */

#define CACHELINE_SIZE        (64)
#define CACHELINE_MASK        (~(CACHELINE_SIZE - 1))
#define CACHELINE_ALIGN(addr) (((addr) + CACHELINE_SIZE - 1) & CACHELINE_MASK)

static inline bool arch_has_clwb(void)
{
    return static_cpu_has(X86_FEATURE_CLWB);
}

extern int support_clwb;

#define _mm_clflush(addr) \
    asm volatile("clflush %0" : "+m"(*(volatile char *)(addr)))
#define _mm_clflushopt(addr) \
    asm volatile(".byte 0x66; clflush %0" : "+m"(*(volatile char *)(addr)))
#define _mm_clwb(addr) \
    asm volatile(".byte 0x66; xsaveopt %0" : "+m"(*(volatile char *)(addr)))

static inline void PERSISTENT_BARRIER(void)
{
    asm volatile("sfence\n" : :);
}

static inline void MFENCE(void)
{
    asm volatile("mfence\n" : :);
}

static inline void hk_flush_small_buffer(void *buf, uint32_t len, bool fence)
{
    uint32_t i;

    len = len + ((unsigned long)(buf) & (CACHELINE_SIZE - 1));
    for (i = 0; i < len; i += CACHELINE_SIZE)
        _mm_clflushopt(buf + i);
    /* Do a fence only if asked. We often don't need to do a fence
     * immediately after clflush because even if we get context switched
     * between clflush and subsequent fence, the context switch operation
     * provides implicit fence.
     */
    if (fence)
        PERSISTENT_BARRIER();
}

static inline void hk_flush_buffer(void *buf, uint32_t len, bool fence)
{
    uint32_t i;

    len = len + ((unsigned long)(buf) & (CACHELINE_SIZE - 1));

    HK_ASSERT(((unsigned long)(buf) & (CACHELINE_SIZE - 1)) == 0);
    if (((unsigned long)(buf) & (CACHELINE_SIZE - 1)) != 0) {
        dump_stack();
        ssleep(1);
    }

    if (support_clwb) {
        for (i = 0; i < len; i += CACHELINE_SIZE)
            _mm_clwb(buf + i);
    } else {
        for (i = 0; i < len; i += CACHELINE_SIZE)
            _mm_clflush(buf + i);
    }
    /* Do a fence only if asked. We often don't need to do a fence
     * immediately after clflush because even if we get context switched
     * between clflush and subsequent fence, the context switch operation
     * provides implicit fence.
     */
    if (fence)
        PERSISTENT_BARRIER();
}

#endif /* _HK_CONFIG_H_ */