[PATCH] add support for zstd

Coiby Xu coxu at redhat.com
Sun Jun 6 23:02:03 PDT 2021


On Mon, Jun 07, 2021 at 01:25:47AM +0000, HAGIO KAZUHITO(萩尾 一仁) wrote:
>-----Original Message-----
>> Date: Tue, 1 Jun 2021 15:43:00 +0800
>> Subject: [PATCH] add support for zstd
>>
>> Add support for zstd
>
>Thanks for the patch, but we've worked on the zstd support based on
>these test patches:
>https://github.com/k-hagio/makedumpfile/commit/f6eaf2424f41d8e9af40f7ce67e0f52b387311af
>https://github.com/k-hagio/crash/commit/5c55c380120d7b7d450e07c4605aaf330f6219dc
>
>I would like to proceed with those, please wait for a while.
>
>Coiby, do you have any patch you can share and how is the state?
>IIRC, your draft patches supported also decompression etc.

The latest work can be found on
https://github.com/coiby/makedumpfile/tree/zstd_context. I've done
some simple tests following your previous suggestions. But I still need
to do some tests on some huge vmcores to provide a benchmark as
suggested by Dave.

>
>Thanks,
>Kazu
>
>>
>> Signed-off-by: Zhang Yunkai <zhang.yunkai at zte.com.cn>
>> ---
>>  Makefile       |  5 +++++
>>  diskdump_mod.h |  1 +
>>  makedumpfile.c | 36 ++++++++++++++++++++++++++++++------
>>  makedumpfile.h |  1 +
>>  4 files changed, 37 insertions(+), 6 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index 5d61a69..725c186 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -68,6 +68,11 @@ endif
>>  CFLAGS += -DUSESNAPPY
>>  endif
>>
>> +ifeq ($(USEZSTD), on)
>> +LIBS := -lzstd $(LIBS)
>> +CFLAGS += -DUSEZSTD
>> +endif
>> +
>>  LIBS := $(LIBS) -lpthread
>>
>>  try-run = $(shell set -e;      \
>> diff --git a/diskdump_mod.h b/diskdump_mod.h
>> index 3733953..ffd9ab2 100644
>> --- a/diskdump_mod.h
>> +++ b/diskdump_mod.h
>> @@ -98,6 +98,7 @@ struct kdump_sub_header {
>>  #define DUMP_DH_COMPRESSED_INCOMPLETE  0x8
>>                     /* indicate an incomplete dumpfile */
>>  #define DUMP_DH_EXCLUDED_VMEMMAP 0x10  /* unused vmemmap pages are excluded */
>> +#define DUMP_DH_COMPRESSED_ZSTD 0x20
>>
>>  /* descriptor of each page for vmcore */
>>  typedef struct page_desc {
>> diff --git a/makedumpfile.c b/makedumpfile.c
>> index 894c88e..3b588c3 100644
>> --- a/makedumpfile.c
>> +++ b/makedumpfile.c
>> @@ -26,6 +26,9 @@
>>  #include <limits.h>
>>  #include <assert.h>
>>  #include <zlib.h>
>> +#ifdef USEZSTD
>> +#include <zstd.h>
>> +#endif
>>
>>  struct symbol_table    symbol_table;
>>  struct size_table  size_table;
>> @@ -296,10 +299,10 @@ is_cache_page(unsigned long flags)
>>  static inline unsigned long
>>  calculate_len_buf_out(long page_size)
>>  {
>> -   unsigned long len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy;
>> +   unsigned long len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy, len_buf_out_zstd;
>>     unsigned long len_buf_out;
>>
>> -   len_buf_out_zlib = len_buf_out_lzo = len_buf_out_snappy = 0;
>> +   len_buf_out_zlib = len_buf_out_lzo = len_buf_out_snappy = len_buf_out_zstd = 0;
>>
>>  #ifdef USELZO
>>     len_buf_out_lzo = page_size + page_size / 16 + 64 + 3;
>> @@ -309,11 +312,14 @@ calculate_len_buf_out(long page_size)
>>     len_buf_out_snappy = snappy_max_compressed_length(page_size);
>>  #endif
>>
>> +#ifdef USEZSTD
>> +   len_buf_out_zstd = ZSTD_compressBound(page_size);
>> +#endif
>> +
>>     len_buf_out_zlib = compressBound(page_size);
>>
>> -   len_buf_out = MAX(len_buf_out_zlib,
>> -             MAX(len_buf_out_lzo,
>> -                 len_buf_out_snappy));
>> +   len_buf_out = MAX(MAX(len_buf_out_zlib,len_buf_out_zstd),
>> +           MAX(len_buf_out_lzo,len_buf_out_snappy));
>>
>>     return len_buf_out;
>>  }
>> @@ -7235,6 +7241,10 @@ write_kdump_header(void)
>>
>>     if (info->flag_compress & DUMP_DH_COMPRESSED_ZLIB)
>>         dh->status |= DUMP_DH_COMPRESSED_ZLIB;
>> +#ifdef USEZSTD
>> +   else if (info->flag_compress & DUMP_DH_COMPRESSED_ZSTD)
>> +       dh->status |= DUMP_DH_COMPRESSED_ZSTD;
>> +#endif
>>  #ifdef USELZO
>>     else if (info->flag_compress & DUMP_DH_COMPRESSED_LZO)
>>         dh->status |= DUMP_DH_COMPRESSED_LZO;
>> @@ -8589,6 +8599,17 @@ write_kdump_pages_cyclic(struct cache_data *cd_header, struct cache_data *cd_pag
>>             && (size_out < info->page_size)) {
>>             pd.flags = DUMP_DH_COMPRESSED_ZLIB;
>>             pd.size  = size_out;
>> +#ifdef USEZSTD
>> +       } else if ((info->flag_compress & DUMP_DH_COMPRESSED_ZSTD)
>> +               && (size_out = len_buf_out)
>> +               && (len_buf_out = ZSTD_compress((void *)buf_out,
>> +                       size_out, (const void *)buf, info->page_size, 1))
>> +               && (len_buf_out < info->page_size)
>> +             ) {
>> +           CHECK_ZSTD(len_buf_out);
>> +           pd.flags = DUMP_DH_COMPRESSED_ZSTD;
>> +           pd.size  = len_buf_out;
>> +#endif
>>  #ifdef USELZO
>>         } else if (info->flag_lzo_support
>>                && (info->flag_compress & DUMP_DH_COMPRESSED_LZO)
>> @@ -11605,7 +11626,7 @@ main(int argc, char *argv[])
>>
>>     info->block_order = DEFAULT_ORDER;
>>     message_level = DEFAULT_MSG_LEVEL;
>> -   while ((opt = getopt_long(argc, argv, "b:cDd:eEFfg:hi:lpRvXx:", longopts,
>> +   while ((opt = getopt_long(argc, argv, "b:cDd:eEFfg:hi:lpRvXx:z", longopts,
>>         NULL)) != -1) {
>>         switch (opt) {
>>         case OPT_BLOCK_ORDER:
>> @@ -11617,6 +11638,9 @@ main(int argc, char *argv[])
>>         case OPT_COMPRESS_ZLIB:
>>             info->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
>>             break;
>> +       case OPT_COMPRESS_ZSTD:
>> +           info->flag_compress = DUMP_DH_COMPRESSED_ZSTD;
>> +           break;
>>         case OPT_DEBUG:
>>             flag_debug = TRUE;
>>             break;
>> diff --git a/makedumpfile.h b/makedumpfile.h
>> index 79046f2..3fb1b57 100644
>> --- a/makedumpfile.h
>> +++ b/makedumpfile.h
>> @@ -2463,6 +2463,7 @@ struct elf_prstatus {
>>  #define OPT_VERSION             'v'
>>  #define OPT_EXCLUDE_XEN_DOM     'X'
>>  #define OPT_VMLINUX             'x'
>> +#define OPT_COMPRESS_ZSTD       'z'
>>  #define OPT_START               256
>>  #define OPT_SPLIT               OPT_START+0
>>  #define OPT_REASSEMBLE          OPT_START+1
>> --
>> 1.8.3.1

-- 
Best regards,
Coiby




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