On Tue, 12 Oct 2021 18:29:56 +1100
Daniel Axtens <d...@axtens.net> wrote:
> 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.
Perhaps note here that the questions are "up to 4GB".
>
> Signed-off-by: Daniel Axtens <d...@axtens.net>
>
> ---
>
> I've put this as copyright IBM for now - hopefully we can conclude on
> whether we're still doing FSF copyright assignments?
> ---
> grub-core/Makefile.core.def | 5 ++
> grub-core/commands/memtools.c | 157 ++++++++++++++++++++++++++++++++++
> grub-core/kern/mm.c | 4 +
> include/grub/mm.h | 4 +-
> 4 files changed, 168 insertions(+), 2 deletions(-)
> create mode 100644 grub-core/commands/memtools.c
>
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 8022e1c0a794..0cc3a4a500ec 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -2527,3 +2527,8 @@ module = {
> common = commands/i386/wrmsr.c;
> enable = x86;
> };
> +
> +module = {
> + name = memtools;
> + common = commands/memtools.c;
> +};
> diff --git a/grub-core/commands/memtools.c b/grub-core/commands/memtools.c
> new file mode 100644
> index 000000000000..6d5778f4a1b0
> --- /dev/null
> +++ b/grub-core/commands/memtools.c
> @@ -0,0 +1,157 @@
> +/*
> + * GRUB -- GRand Unified Bootloader
> + * Copyright (C) 2021 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
> +
> +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;
> +}
> +
> +
> +#define BIG_ALLOC (64 * 1024 * 1024)
> +#define SMALL_ALLOC 32
Where are these used? A search is coming up with nothing.
> +
> +static grub_err_t
> +grub_cmd_stress_big_allocs (grub_command_t cmd __attribute__ ((unused)),
> + int argc __attribute__ ((unused)),
> + char **args __attribute__ ((unused)))
I'm thinking this would be valuable to be included in the functional
tests. What do you think?
> +{
> + int i, max_mb, blocks_alloced;
> + void *mem;
> + void **blocklist;
> +
> + grub_printf ("Test 1: increasingly sized allocs to 1GB block\n");
Perhaps, "Test 1: Allocate and free up from 1MB to 1GB in 1MB
increments."
> + for (i = 1; i < 1024; i++) {
> + grub_printf ("%d MB . ", i);
> + mem = grub_malloc (i * 1024 * 1024);
> + if (mem == NULL)
> + {
> + grub_printf ("failed\n");
"Failed to allocate a %dMB continuous block of memory.\n"
> + break;
> + }
> + else
> + grub_free (mem);
> +
> + if (i % 10 == 0)
> + grub_printf ("\n");
So every 10Mb a newline is output. That's seems small, if you've got
generally at least 80 char with terminal. Why not make it 64 and thus
evenly divide 1024?
> + }
> +
> + max_mb = i - 1;
> + grub_printf ("Max sized allocation we did was %d MB\n", max_mb);
> +
Line with just a space, should be empty.
> + grub_printf ("Test 2: 1MB at a time, max 4GB\n");
"Test 2: Allocate total of 4GB of memory in 1MB chunks"
> + blocklist = grub_calloc (4096, sizeof (void *));
> + for (i = 0; i < 4096; i++)
> + {
> + blocklist[i] = grub_malloc (1024 * 1024);
> + if (!blocklist[i])
> + {
> + grub_printf ("Ran out of memory at iteration %d\n", i);
"Failed to allocate 1MB memory chunk on block %d of 4096"
> + break;
> + }
> + }
> + blocks_alloced = i;
> + for (i = 0; i < blocks_alloced; i++)
> + grub_free (blocklist[i]);
> +
> + grub_printf ("\nTest 3: 1MB aligned 900kB + 100kB\n");
"Test 3: Allocate total of 4Gb of memory in 1MB aligned 900kB + 100kB
chunks"
> + //grub_mm_debug=1;
Was this comment intended to be included? If so, why here?
> + for (i = 0; i < 4096; i += 2)
> + {
> + blocklist[i] = grub_memalign (1024 * 1024, 900 * 1024);
> + if (!blocklist[i])
> + {
> + grub_printf ("Failed big allocation, iteration %d\n", i);
> + blocks_alloced = i;
> + break;
> + }
> +
> + blocklist[i + 1] = grub_malloc (100 * 1024);
> + if (!blocklist[i + 1])
> + {
> + 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);
> +
> + 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."));
Leading space characters.
> +#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 835ed8a8f6f9..032c8f71aed2 100644
> --- a/grub-core/kern/mm.c
> +++ b/grub-core/kern/mm.c
> @@ -556,6 +556,8 @@ 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
> @@ -583,6 +585,8 @@ 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;
> diff --git a/include/grub/mm.h b/include/grub/mm.h
> index 9c38dd3ca5d2..44fde7cb9033 100644
> --- a/include/grub/mm.h
> +++ b/include/grub/mm.h
> @@ -46,8 +46,8 @@ void grub_mm_check_real (const char *file, int line);
> /* Set this variable to 1 when you want to trace all memory function calls.
> */
> extern int EXPORT_VAR(grub_mm_debug);
>
> -void grub_mm_dump_free (void);
> -void grub_mm_dump (unsigned lineno);
> +void EXPORT_FUNC(grub_mm_dump_free) (void);
> +void EXPORT_FUNC(grub_mm_dump) (unsigned lineno);
This makes me wonder if we could easily move grub_mm_dump and
grub_mm_dump_free to memtools.c, and always have them built and lsmem
and lsmemfree as well. IOW, lsmem would work without need to compile
with --enable-mm-debug. If so, since its compiled as a module there's
not an issue of it increasing the core size.
>
> #define grub_calloc(nmemb, size) \
> grub_debug_calloc (GRUB_FILE, __LINE__, nmemb, size)
Glenn
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