Re: [PATCH v3 5/6] Add memtool module with memory allocation stress-test

[Glenn Washburn]

On Mon, 30 Jan 2023 14:16:20 -0500
Stefan Berger <stefanb@linux.ibm.com> wrote:

> From: Daniel Axtens <dja@axtens.net>
> 
> When working on memory, it's nice to be able to test your work.
> 
> Add a memtest module. When compiled with --enable-mm-debug, it exposes
> 3 commands:
> 
>  * lsmem - print all allocations and free space in all regions
>  * lsfreemem - print free space in all regions
> 
>  * stress_big_allocs - stress test large allocations:
>   - how much memory can we allocate in one chunk?
>   - how many 1MB chunks can we allocate?
>   - check that gap-filling works with a 1MB aligned 900kB alloc + a
>      100kB alloc.
> 
> Signed-off-by: Daniel Axtens <dja@axtens.net>
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
> ---
>  configure.ac                  |   1 +
>  grub-core/Makefile.core.def   |   6 ++
>  grub-core/commands/memtools.c | 160
> ++++++++++++++++++++++++++++++++++ grub-core/kern/mm.c           |
> 4 + 4 files changed, 171 insertions(+)
>  create mode 100644 grub-core/commands/memtools.c
> 
> diff --git a/configure.ac b/configure.ac
> index 93626b798..ca42ff8f7 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1520,6 +1520,7 @@ else
>    MM_DEBUG=0
>  fi
>  AC_SUBST([MM_DEBUG])
> +AM_CONDITIONAL([COND_MM_DEBUG], [test x$MM_DEBUG = x1])
>  
>  AC_ARG_ENABLE([cache-stats],
>             AS_HELP_STRING([--enable-cache-stats],
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 71093a100..6d30fd11f 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -2548,3 +2548,9 @@ module = {
>    common = commands/i386/wrmsr.c;
>    enable = x86;
>  };
> +
> +module = {
> +  name = memtools;
> +  common = commands/memtools.c;
> +  condition = COND_MM_DEBUG;
> +};
> diff --git a/grub-core/commands/memtools.c
> b/grub-core/commands/memtools.c new file mode 100644
> index 000000000..3471e5941
> --- /dev/null
> +++ b/grub-core/commands/memtools.c
> @@ -0,0 +1,160 @@
> +/*
> + *  GRUB  --  GRand Unified Bootloader
> + *  Copyright (C) 2022 Free Software Foundation, Inc.
> + *  Copyright (C) 2022 IBM Corporation
> + *
> + *  GRUB is free software: you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as
> published by
> + *  the Free Software Foundation, either version 3 of the License, or
> + *  (at your option) any later version.
> + *
> + *  GRUB is distributed in the hope that it will be useful,
> + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + *  GNU General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License
> + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <config.h>
> +#include <grub/dl.h>
> +#include <grub/misc.h>
> +#include <grub/command.h>
> +#include <grub/i18n.h>
> +#include <grub/memory.h>
> +#include <grub/mm.h>
> +
> +GRUB_MOD_LICENSE ("GPLv3+");
> +
> +#ifdef MM_DEBUG

Since you added the line "condition = COND_MM_DEBUG;" to
grub-core/Makefile.core.def above. Are these "#ifdef MM_DEBUG" lines in
this file needed? And if they still are needed, why? I think we should
try to get rid of them.

Glenn

> +
> +static grub_err_t
> +grub_cmd_lsmem (grub_command_t cmd __attribute__ ((unused)),
> +              int argc __attribute__ ((unused)),
> +              char **args __attribute__ ((unused)))
> +
> +{
> +#ifndef GRUB_MACHINE_EMU
> +  grub_mm_dump (0);
> +#endif
> +
> +  return 0;
> +}
> +
> +static grub_err_t
> +grub_cmd_lsfreemem (grub_command_t cmd __attribute__ ((unused)),
> +                 int argc __attribute__ ((unused)),
> +                 char **args __attribute__ ((unused)))
> +
> +{
> +#ifndef GRUB_MACHINE_EMU
> +  grub_mm_dump_free ();
> +#endif
> +
> +  return 0;
> +}
> +
> +
> +static grub_err_t
> +grub_cmd_stress_big_allocs (grub_command_t cmd __attribute__
> ((unused)),
> +                         int argc __attribute__ ((unused)),
> +                         char **args __attribute__ ((unused)))
> +{
> +  int i, max_mb, blocks_alloced;
> +  void *mem;
> +  void **blocklist;
> +
> +  grub_printf ("Test 1: increasingly sized allocs to 1GB block\n");
> +  for (i = 1; i < 1024; i++)
> +    {
> +      grub_printf ("%4d MB . ", i);
> +      mem = grub_malloc (i * 1024 * 1024);
> +      if (mem == NULL)
> +     {
> +       grub_printf ("failed\n");
> +       break;
> +     }
> +      else
> +     grub_free (mem);
> +
> +      if (i % 7 == 0)
> +     grub_printf ("\n");
> +    }
> +
> +  max_mb = i - 1;
> +  grub_printf ("\nMax sized allocation we did was %d MB\n", max_mb);
> +
> +  grub_printf ("\nTest 2: 1MB at a time, max 4GB\n");
> +  blocklist = grub_calloc (4096, sizeof (void *));
> +  for (i = 0; i < 4096; i++)
> +    {
> +      blocklist[i] = grub_malloc (1024 * 1024);
> +      if (blocklist[i] == NULL)
> +     {
> +       grub_printf ("Ran out of memory at iteration %d\n", i);
> +       break;
> +     }
> +    }
> +  blocks_alloced = i;
> +  for (i = 0; i < blocks_alloced; i++)
> +    grub_free (blocklist[i]);
> +
> +  grub_printf ("\nTest 3: 1MB aligned 900kB + 100kB\n");
> +  /* grub_mm_debug=1;*/
> +  for (i = 0; i < 4096; i += 2)
> +    {
> +      blocklist[i] = grub_memalign (1024 * 1024, 900 * 1024);
> +      if (blocklist[i] == NULL)
> +     {
> +       grub_printf ("Failed big allocation, iteration %d\n", i);
> +       blocks_alloced = i;
> +       break;
> +     }
> +
> +      blocklist[i + 1] = grub_malloc (100 * 1024);
> +      if (blocklist[i + 1] == NULL)
> +     {
> +       grub_printf ("Failed small allocation, iteration %d\n", i);
> +       blocks_alloced = i + 1;
> +       break;
> +     }
> +      grub_printf (".");
> +    }
> +  for (i = 0; i < blocks_alloced; i++)
> +    grub_free (blocklist[i]);
> +
> +  grub_free (blocklist);
> +
> +#if defined(__powerpc__)
> +  grub_printf ("\nA reboot may now be required.\n");
> +#endif
> +
> +  grub_errno = GRUB_ERR_NONE;
> +  return GRUB_ERR_NONE;
> +}
> +
> +static grub_command_t cmd_lsmem, cmd_lsfreemem, cmd_sba;
> +
> +#endif /* MM_DEBUG */
> +
> +GRUB_MOD_INIT (memtools)
> +{
> +#ifdef MM_DEBUG
> +  cmd_lsmem = grub_register_command ("lsmem", grub_cmd_lsmem,
> +                                  0, N_("List free and allocated
> memory blocks."));
> +  cmd_lsfreemem = grub_register_command ("lsfreemem",
> grub_cmd_lsfreemem,
> +                                      0, N_("List free memory
> blocks."));
> +  cmd_sba = grub_register_command ("stress_big_allocs",
> grub_cmd_stress_big_allocs,
> +                                0, N_("Stress test large
> allocations.")); +#endif
> +}
> +
> +GRUB_MOD_FINI (memtools)
> +{
> +#ifdef MM_DEBUG
> +  grub_unregister_command (cmd_lsmem);
> +  grub_unregister_command (cmd_lsfreemem);
> +  grub_unregister_command (cmd_sba);
> +#endif
> +}
> diff --git a/grub-core/kern/mm.c b/grub-core/kern/mm.c
> index 94eb29108..792ab0a83 100644
> --- a/grub-core/kern/mm.c
> +++ b/grub-core/kern/mm.c
> @@ -734,6 +734,8 @@ grub_mm_dump_free (void)
>      {
>        grub_mm_header_t p;
>  
> +      grub_printf ("Region %p (size %" PRIuGRUB_SIZE ")\n\n", r,
> r->size); +
>        /* Follow the free list.  */
>        p = r->first;
>        do
> @@ -761,6 +763,8 @@ grub_mm_dump (unsigned lineno)
>      {
>        grub_mm_header_t p;
>  
> +      grub_printf ("Region %p (size %" PRIuGRUB_SIZE ")\n\n", r,
> r->size); +
>        for (p = (grub_mm_header_t) ALIGN_UP ((grub_addr_t) (r + 1),
>                                           GRUB_MM_ALIGN);
>          (grub_addr_t) p < (grub_addr_t) (r+1) + r->size;