Hi Kazu


a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage")

zspage6 meam linux 6 and later, because I don't have a better way at the moment.


ffedd09fa9b06 ("zsmalloc: Stop using slab fields in struct page")

using page->index to store 'page' (page->index and page->freelist are at the same offset in struct page).


f635725c3905e ("zram: do not waste zram_table_entry flags bits")

-#define ZRAM_FLAG_SHIFT 24
+#define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1)

enum zram_pageflags {
    /* zram slot is locked */
    ZRAM_LOCK = ZRAM_FLAG_SHIFT,
    ZRAM_SAME,  /* Page consists the same element */
    ZRAM_WB,    /* page is stored on backing_device */
    ZRAM_UNDER_WB,  /* page is under writeback */
    ZRAM_HUGE,  /* Incompressible page */
    ZRAM_IDLE,  /* not accessed page since last idle marking */
    ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */

    ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */
    ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */

    __NR_ZRAM_PAGEFLAGS,
};

Thanks


发件人: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@nec.com>
发送时间: 2023年10月4日 9:33:57
收件人: 陈冠有; crash-utility@redhat.com
抄送: lijiang@redhat.com
主题: [External Mail]Re: [PATCH v4] Fix: move huge compressed obj from page to zspage
 
[外部邮件] 此邮件来源于小米公司外部,请谨慎处理。若对邮件安全性存疑,请将邮件转发给misec@xiaomi.com进行反馈

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
>
>
> #/******本邮件及其附件含有小米公司的保密信息,仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用(包括但不限于全部或部分地泄露、复制、或散发)本邮件中的信息。如果您错收了本邮件,请您立即电话或邮件通知发件人并删除本邮件! This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#
#/******本邮件及其附件含有小米公司的保密信息,仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用(包括但不限于全部或部分地泄露、复制、或散发)本邮件中的信息。如果您错收了本邮件,请您立即电话或邮件通知发件人并删除本邮件! This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#