Messages in this thread Patch in this message | | | From | vjitta@codeauro ... | Subject | [PATCH v3] lib: stackdepot: Add support to configure STACK_HASH_SIZE | Date | Thu, 10 Dec 2020 10:30:01 +0530 |
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From: Yogesh Lal <ylal@codeaurora.org>
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.
Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> --- lib/stackdepot.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 81c69c0..e0eebfd 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -30,6 +30,7 @@ #include <linux/stackdepot.h> #include <linux/string.h> #include <linux/types.h> +#include <linux/vmalloc.h> #define DEPOT_STACK_BITS (sizeof(depot_stack_handle_t) * 8) @@ -141,14 +142,36 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, return stack; } -#define STACK_HASH_ORDER 20 -#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER) +#define MAX_STACK_HASH_ORDER 20 +#define MAX_STACK_HASH_SIZE (1L << MAX_STACK_HASH_ORDER) +#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 unsigned int stack_hash_order = 20; +static struct stack_record *stack_table_def[MAX_STACK_HASH_SIZE] __initdata = { + [0 ... MAX_STACK_HASH_SIZE - 1] = NULL }; +static struct stack_record **stack_table __refdata = stack_table_def; + +static int __init setup_stack_hash_order(char *str) +{ + kstrtouint(str, 0, &stack_hash_order); + if (stack_hash_order > MAX_STACK_HASH_ORDER) + stack_hash_order = MAX_STACK_HASH_ORDER; + return 0; +} +early_param("stack_hash_order", setup_stack_hash_order); + +static int __init init_stackdepot(void) +{ + size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *)); + + stack_table = vmalloc(size); + memcpy(stack_table, stack_table_def, size); + return 0; +} +early_initcall(init_stackdepot); /* Calculate hash for a stack */ static inline u32 hash_stack(unsigned long *entries, unsigned int size) -- 2.7.4 QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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