Hi Shivang,
On Wed, Dec 3, 2025 at 11:21 PM Shivang Upadhyay <[email protected]> wrote:
>
> the default value of MAX_MALLOC_BUFS is 3072, but can be changed with
> command line with flag `--max-malloc-bufs`.
>
> Signed-off-by: Shivang Upadhyay <[email protected]>
> ---
> defs.h | 1 +
> main.c | 4 ++++
> tools.c | 9 ++++++---
> 3 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index ab4aee8..863baf9 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -5608,6 +5608,7 @@ void exec_args_input_file(struct command_table_entry *,
> struct args_input_file *
> /*
> * tools.c
> */
> +extern int MAX_MALLOC_BUFS;
> FILE *set_error(char *);
> int __error(int, char *, ...);
> #define error __error /* avoid conflict with gdb error() */
> diff --git a/main.c b/main.c
> index 71bcc15..e986792 100644
> --- a/main.c
> +++ b/main.c
> @@ -46,6 +46,7 @@ static struct option long_options[] = {
> {"version", 0, 0, 0},
> {"buildinfo", 0, 0, 0},
> {"cpus", required_argument, 0, 0},
> + {"max-malloc-bufs", required_argument, 0, 0},
> {"no_ikconfig", 0, 0, 0},
> {"hyper", 0, 0, 0},
> {"p2m_mfn", required_argument, 0, 0},
> @@ -163,6 +164,9 @@ main(int argc, char **argv)
> else if (STREQ(long_options[option_index].name,
> "cpus"))
> kt->cpus_override = optarg;
>
> + else if (STREQ(long_options[option_index].name,
> "max-malloc-bufs"))
> + MAX_MALLOC_BUFS = atoi(optarg);
Thanks for your improvement!
Do we need to set 3072 as the minimum value? like, MAX_MALLOC_BUFS =
MAX_MALLOC_BUFS > 3072 ? MAX_MALLOC_BUFS : 3072. If user set a value
like 1000, which is likely to make crash unusable, and a minimum value
will prevent users from the mistakes.
> +
> else if (STREQ(long_options[option_index].name,
> "hyper"))
> pc->flags |= XEN_HYPER;
>
> diff --git a/tools.c b/tools.c
> index a9ad18d..69250c4 100644
> --- a/tools.c
> +++ b/tools.c
> @@ -5698,7 +5698,7 @@ ll_power(long long base, long long exp)
> #define B32K (4)
>
> #define SHARED_BUF_SIZES (B32K+1)
> -#define MAX_MALLOC_BUFS (2000)
> +int MAX_MALLOC_BUFS = 3072; /* can be changed from command line args */
> #define MAX_CACHE_SIZE (KILOBYTES(32))
>
> struct shared_bufs {
> @@ -5723,7 +5723,7 @@ struct shared_bufs {
> long buf_8K_ovf;
> long buf_32K_ovf;
> int buf_inuse[SHARED_BUF_SIZES];
> - char *malloc_bp[MAX_MALLOC_BUFS];
> + char **malloc_bp;
> long smallest;
> long largest;
> long embedded;
> @@ -5744,6 +5744,7 @@ buf_init(void)
>
> bp->smallest = 0x7fffffff;
> bp->total = 0.0;
> + bp->malloc_bp = (char**) calloc(MAX_MALLOC_BUFS * sizeof(char*), 1);
>
> #ifdef VALGRIND
> VALGRIND_MAKE_MEM_NOACCESS(&bp->buf_1K, sizeof(bp->buf_1K));
> @@ -6130,7 +6131,9 @@ getbuf(long reqsize)
> dump_shared_bufs();
>
> return ((char *)(long)
> - error(FATAL, "cannot allocate any more memory!\n"));
> + error(FATAL, "cannot allocate any more memory!\n"
> + "try increasing --max-malloc-bufs (current
> value : %d)\n",
> + MAX_MALLOC_BUFS));
> }
>
> /*
> --
> 2.52.0
>
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