The patch titled Subject: lib: stackdepot: add support to configure STACK_HASH_SIZE has been added to the -mm tree. Its filename is lib-stackdepot-add-support-to-configure-stack_hash_size.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/lib-stackdepot-add-support-to-configure-stack_hash_size.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/lib-stackdepot-add-support-to-configure-stack_hash_size.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Yogesh Lal <ylal@xxxxxxxxxxxxxx> Subject: lib: stackdepot: add support to configure STACK_HASH_SIZE Add a kernel parameter stack_hash_order to configure STACK_HASH_SIZE. Aim is to have configurable value for STACK_HASH_SIZE, so that one can configure it depending on usecase there by reducing the static memory overhead. One example is of Page Owner, default value of STACK_HASH_SIZE lead stack depot to consume 8MB of static memory. Making it configurable and use lower value helps to enable features like CONFIG_PAGE_OWNER without any significant overhead. Link: https://lkml.kernel.org/r/1606365835-3242-1-git-send-email-vjitta@xxxxxxxxxxxxxx Suggested-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Yogesh Lal <ylal@xxxxxxxxxxxxxx> Signed-off-by: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Mark Brown <broonie@xxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx> Cc: Zhenhua Huang <zhenhuah@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/stackdepot.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) --- a/lib/stackdepot.c~lib-stackdepot-add-support-to-configure-stack_hash_size +++ a/lib/stackdepot.c @@ -141,14 +141,31 @@ static struct stack_record *depot_alloc_ return stack; } -#define STACK_HASH_ORDER 20 -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) +static unsigned int stack_hash_order = 20; +#define STACK_HASH_SIZE (1L << stack_hash_order) #define STACK_HASH_MASK (STACK_HASH_SIZE - 1) #define STACK_HASH_SEED 0x9747b28c -static struct stack_record *stack_table[STACK_HASH_SIZE] = { - [0 ... STACK_HASH_SIZE - 1] = NULL -}; +static struct stack_record **stack_table; + +static int __init setup_stack_hash_order(char *str) +{ + kstrtouint(str, 0, &stack_hash_order); + return 0; +} +early_param("stack_hash_order", setup_stack_hash_order); + +static int __init init_stackdepot(void) +{ + int i; + + stack_table = kvmalloc(sizeof(struct stack_record *) * STACK_HASH_SIZE, GFP_KERNEL); + for (i = 0; i < STACK_HASH_SIZE; i++) + stack_table[i] = NULL; + return 0; +} + +early_initcall(init_stackdepot); /* Calculate hash for a stack */ static inline u32 hash_stack(unsigned long *entries, unsigned int size) _ Patches currently in -mm which might be from ylal@xxxxxxxxxxxxxx are lib-stackdepot-add-support-to-configure-stack_hash_size.patch