Date: Wed, 6 Apr 2022 02:07:47 +0000
From: HAGIO KAZUHITO(?????)  <k-hagio-ab@nec.com>
To: Huang Shijie <shijie@os.amperecomputing.com>, "lijiang@redhat.com"
        <lijiang@redhat.com>
Cc: "patches@amperecomputing.com" <patches@amperecomputing.com>,
        "zwang@amperecomputing.com" <zwang@amperecomputing.com>,
        "darren@os.amperecomputing.com" <darren@os.amperecomputing.com>,
        "crash-utility@redhat.com" <crash-utility@redhat.com>
Subject: Re: [Crash-utility] [PATCH v2] diskdump: use mmap/madvise to
        improve the start-up
Message-ID:
        <TYYPR01MB67776D37C6B5F947EBAE6750DDE79@TYYPR01MB6777.jpnprd01.prod.outlook.com>

Content-Type: text/plain; charset="iso-2022-jp"

-----Original Message-----
> 1.) The bitmap of vmcore file can be very big in the server kernel panic,
>     such as over 256M.
>
>     This patch uses mmap/madvise to improve the read speed
>     of the bitmap in the non-FLAT_FORMAT code path.
>
>     Use MADV_WILLNEED for madvise, it will trigger read ahead for
>     reading the bitmap.

Thanks for the update.

With removing the unused variables (will be fixed when merging),
Acked-by: Kazuhito Hagio <k-hagio-ab@nec.com>

$ make clean ; make warn

diskdump.c: In function ?read_dump_header?:
diskdump.c:543:10: warning: unused variable ?bytes_read? [-Wunused-variable]
  ssize_t bytes_read;
          ^~~~~~~~~~
diskdump.c:542:9: warning: unused variable ?len? [-Wunused-variable]
  size_t len;
         ^~~
diskdump.c:541:8: warning: unused variable ?bufptr? [-Wunused-variable]
  char *bufptr;
        ^~~~~~

As for a second ack, please wait for a while.
Lianbo is taking a leave and will be back soon.

Thanks,
Kazu