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On 2023/09/20 12:28, 陈冠有 wrote:
> when zspage define 'huge', crash-utility zram decompress fail.
> we need to be compatible with the previous kernel,
> so we can't define 'huge' directly in zspage.

Thank you for the patch, is this v4 patch the latest one?

>
> Before:
> crash> mod -s zram zram.ko
>       MODULE       NAME                                          BASE           SIZE  OBJECT FILE
> ffffffde224db800  zram                                    ffffffde224d2000    57344  zram.ko
> crash> mod -s zsmalloc zsmalloc.ko
>       MODULE       NAME                                          BASE           SIZE  OBJECT FILE
> ffffffde224c5180  zsmalloc                                ffffffde224bf000    40960  zsmalloc.ko
> crash> rd 0x13d89fb0
> rd: zspage magic incorrect: b0
>
> After:
> crash> rd 0x13d89fb0
>          13d89fb0:  c2b54f7170883b20                     ;.pqO..
>
> Link: https://lkml.kernel.org/r/20211115185909.3949505-6-minchan@kernel.org

Please use the commit information if it's already in the kernel.
a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")

>
> Signed-off-by: chenguanyou <chenguanyou@xiaomi.com>
> ---
>   defs.h     | 13 +++++++++++
>   diskdump.c | 67 ++++++++++++++++++++++++++++++++++++++++++++----------
>   2 files changed, 68 insertions(+), 12 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index 96a7a2a..0af69cc 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2225,6 +2225,7 @@ struct offset_table {                    /* stash of commonly-used offsets */
>      long module_memory_base;
>      long module_memory_size;
>      long irq_data_irq;
> +   long zspage_huge;
>   };
>
>   struct size_table {         /* stash of commonly-used sizes */
> @@ -7221,6 +7222,18 @@ struct zspage {
>       unsigned int freeobj;
>   };
>
> +struct zspage6 {

Why is this name "zspage6"?

> +    struct {
> +        unsigned int huge : 1;
> +        unsigned int fullness : 2;
> +        unsigned int class : 9;
> +        unsigned int isolated : 3;
> +        unsigned int magic : 8;
> +    };
> +    unsigned int inuse;
> +    unsigned int freeobj;
> +};
> +
>   /*
>    * makedumpfile.c
>    */
> diff --git a/diskdump.c b/diskdump.c
> index 2c284ff..02aaf1b 100644
> --- a/diskdump.c
> +++ b/diskdump.c
> @@ -2754,6 +2754,9 @@ zram_init(void)
>      if (INVALID_MEMBER(zram_table_flag))
>          MEMBER_OFFSET_INIT(zram_table_flag, "zram_table_entry", "value");
>      STRUCT_SIZE_INIT(zram_table_entry, "zram_table_entry");
> +    MEMBER_OFFSET_INIT(zspoll_size_class, "zs_pool", "size_class");
> +    MEMBER_OFFSET_INIT(size_class_size, "size_class", "size");
> +    MEMBER_OFFSET_INIT(zspage_huge, "zspage", "huge");
>   }
>
>   static unsigned char *
> @@ -2761,9 +2764,11 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
>   {
>      ulong obj, off, class, page, zspage;
>      struct zspage zspage_s;
> +   struct zspage6 zspage6_s;
>      physaddr_t paddr;
>      unsigned int obj_idx, class_idx, size;
>      ulong pages[2], sizes[2];
> +   ulong zs_magic;
>
>      readmem(handle, KVADDR, &obj, sizeof(void *), "zram entry", FAULT_ON_ERROR);
>      obj >>= OBJ_TAG_BITS;
> @@ -2772,11 +2777,19 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
>
>      readmem(page + OFFSET(page_private), KVADDR, &zspage,
>              sizeof(void *), "page_private", FAULT_ON_ERROR);
> -   readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
>
> -   class_idx = zspage_s.class;
> -   if (zspage_s.magic != ZSPAGE_MAGIC)
> -       error(FATAL, "zspage magic incorrect: %x\n", zspage_s.magic);
> +   if (VALID_MEMBER(zspage_huge)) {
> +       readmem(zspage, KVADDR, &zspage6_s, sizeof(struct zspage6), "zspage6", FAULT_ON_ERROR);
> +       class_idx = zspage6_s.class;
> +       zs_magic = zspage6_s.magic;
> +   } else {
> +       readmem(zspage, KVADDR, &zspage_s, sizeof(struct zspage), "zspage", FAULT_ON_ERROR);
> +       class_idx = zspage_s.class;
> +       zs_magic = zspage_s.magic;
> +   }
> +
> +   if (zs_magic != ZSPAGE_MAGIC)
> +       error(FATAL, "zspage magic incorrect: %x\n", zs_magic);
>
>      class = pool + OFFSET(zspoll_size_class);
>      class += (class_idx * sizeof(void *));
> @@ -2794,8 +2807,13 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
>      }
>
>      pages[0] = page;
> -   readmem(page + OFFSET(page_freelist), KVADDR, &pages[1],
> -           sizeof(void *), "page_freelist", FAULT_ON_ERROR);
> +   if (VALID_MEMBER(page_freelist)) {
> +       readmem(page + OFFSET(page_freelist), KVADDR, &pages[1],
> +               sizeof(void *), "page_freelist", FAULT_ON_ERROR);
> +   } else {
> +       readmem(page + OFFSET(page_index), KVADDR, &pages[1],
> +               sizeof(void *), "page_index", FAULT_ON_ERROR);
> +   }

What is the kernel commit related to this hunk?

>      sizes[0] = PAGESIZE() - off;
>      sizes[1] = size - sizes[0];
>      if (!is_page_ptr(pages[0], &paddr)) {
> @@ -2812,9 +2830,15 @@ zram_object_addr(ulong pool, ulong handle, unsigned char *zram_buf)
>      readmem(paddr, PHYSADDR, zram_buf + sizes[0], sizes[1], "zram buffer[1]", FAULT_ON_ERROR);
>
>   out:
> -   readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);
> -   if (!(obj & (1<<10))) { //PG_OwnerPriv1 flag
> -       return (zram_buf + ZS_HANDLE_SIZE);
> +   if (!VALID_MEMBER(zspage_huge)) {
> +       readmem(page, KVADDR, &obj, sizeof(void *), "page flags", FAULT_ON_ERROR);
> +       if (!(obj & (1<<10))) { //PG_OwnerPriv1 flag
> +           return (zram_buf + ZS_HANDLE_SIZE);
> +       }
> +   } else {
> +       if (!zspage6_s.huge) {
> +           return (zram_buf + ZS_HANDLE_SIZE);
> +       }
>      }
>
>      return zram_buf;
> @@ -2929,6 +2953,11 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
>      unsigned char *outbuf = NULL;
>      ulong zram, zram_table_entry, sector, index, entry, flags, size,
>          outsize, off;
> +   unsigned long *same_buf = NULL;
> +   bool is_same = false;
> +   ulong ZRAM_SAME_PAGEFLAG;
> +   ulong ZRAM_WB_PAGEFLAG;
> +   long ZRAM_LOCK_VALUE = 24;
>
>      if (INVALID_MEMBER(zram_compressor)) {
>          zram_init();
> @@ -2992,11 +3021,25 @@ try_zram_decompress(ulonglong pte_val, unsigned char *buf, ulong len, ulonglong
>          sizeof(void *), "entry of table", FAULT_ON_ERROR);
>      readmem(zram_table_entry + OFFSET(zram_table_flag), KVADDR, &flags,
>          sizeof(void *), "zram_table_flag", FAULT_ON_ERROR);
> -   if (!entry || (flags & ZRAM_FLAG_SAME_BIT)) {
> -       memset(buf, entry, len);
> +
> +   if (!enumerator_value("ZRAM_LOCK", &ZRAM_LOCK_VALUE)
> +           && THIS_KERNEL_VERSION >= LINUX(6,1,0))
> +       ZRAM_LOCK_VALUE = PAGESHIFT() + 1;
> +
> +   ZRAM_SAME_PAGEFLAG = ZRAM_LOCK_VALUE + 1;
> +   ZRAM_WB_PAGEFLAG = ZRAM_LOCK_VALUE + 2;
> +
> +   if (!entry || flags & (1 << ZRAM_SAME_PAGEFLAG)) {
> +       same_buf = (unsigned long *)GETBUF(PAGESIZE());
> +       for (int count = 0; count < PAGESIZE() / sizeof(unsigned long); count++) {
> +           same_buf[count] = entry;
> +       }
> +       memcpy(buf, same_buf + off, PAGESIZE());
> +       FREEBUF(same_buf);

What is the kernel commit related to this hunk?

And I could not apply this, could you resend it as a plain text email or
an attached plain text file?

Thanks,
Kazu

>          goto out;
>      }
> -   size = flags & (ZRAM_FLAG_SHIFT -1);
> +
> +   size = flags & ((1 << ZRAM_LOCK_VALUE) - 1);
>      if (size == 0) {
>          len = 0;
>          goto out;
> --
> 2.39.0
>
>
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