On Wed, Nov 6, 2024 at 10:41 AM <devel-request(a)lists.crash-utility.osci.io>
wrote:
 Date: Tue,  5 Nov 2024 15:59:32 +1300
 From: Tao Liu <ltao(a)redhat.com>
 Subject: [Crash-utility] [PATCH] Mark --log option as deprecated
 To: devel(a)lists.crash-utility.osci.io
 Cc: Tao Liu <ltao(a)redhat.com>
 Message-ID: <20241105025932.59489-1-ltao(a)redhat.com>
 Content-Type: text/plain; charset="US-ASCII"; x-default=true
 Since kernel(>=v5.10), a new lockless ringbuffer is introduced. And
 crash commit a5531b24 ("printk: add support for lockless ringbuffer")
 implemented the lockless ringbuffer dumping for cmd_log, this however,
 relies on the existence of kernel debuginfo.
 Since there is already a similar function been implemented for
 makedumpfile, aka "makedumpfile --dump-dmesg" to dump dmesg logs with
 only vmcore, there is no need to maintain a similar code in crash
 as well. In addition, this option is not widely used, so just mark
 "--log" option as deprecated for crash.
 
This looks good to me.
Applied(with a minor change):
https://github.com/crash-utility/crash/commit/ca74157283dd43d0036ab6b7b93...
Thanks
Lianbo
 Signed-off-by: Tao Liu <ltao(a)redhat.com>
 ---
  crash.8 | 4 +++-
  help.c  | 4 +++-
  2 files changed, 6 insertions(+), 2 deletions(-)
 diff --git a/crash.8 b/crash.8
 index 0662f92..6abd381 100644
 --- a/crash.8
 +++ b/crash.8
 @@ -333,10 +333,12 @@ or
  .I /proc/kcore
  devices.
  .TP
 -.BI --log \ dumpfile
 +.BI --log \ dumpfile \ (deprecated)
  Dump the contents of the kernel log buffer.  A kernel namelist
  argument is not necessary, but the dumpfile must contain the
  VMCOREINFO data taken from the original /proc/vmcore ELF header.
 +Note: this option is deprecated and will no longer work for
 +kernel(>=v5.10), use "makedumpfile --dump-dmesg" instead.
  .TP
  .B --no_kallsyms
  Do not use kallsyms-generated symbol information contained within
 diff --git a/help.c b/help.c
 index e95ac1d..caf52f5 100644
 --- a/help.c
 +++ b/help.c
 @@ -211,10 +211,12 @@ char *program_usage_info[] = {
      "    Use device as an alternative device to the /dev/crash, /dev/mem",
      "    or /proc/kcore devices.",
      "",
 -    "  --log dumpfile",
 +    "  --log dumpfile (deprecated)",
      "    Dump the contents of the kernel log buffer.  A kernel namelist",
      "    argument is not necessary, but the dumpfile must contain the",
      "    VMCOREINFO data taken from the original /proc/vmcore ELF
 header.",
 +    "    Note: this option is deprecated and will no longer work for",
 +    "    kernel(>=v5.10), use \"makedumpfile --dump-dmesg\"
instead.",
      "",
      "  --no_kallsyms",
      "    Do not use kallsyms-generated symbol information contained
 within",
 --
 2.47.0