xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

FROMGIT: lib: stackdepot: add support to disable stack depot

Browse Source 
Add a kernel parameter stack_depot_disable to disable stack depot.  So
that stack hash table doesn't consume any memory when stack depot is
disabled.

The use case is CONFIG_PAGE_OWNER without page_owner=on.  Without this
patch, stackdepot will consume the memory for the hashtable.  By default,
it's 8M which is never trivial.

With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off,
stack_depot_disable in kernel command line, we could save the wasted
memory for the hashtable.

Link: https://lkml.kernel.org/r/1611749198-24316-2-git-send-email-vjitta@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yogesh Lal <ylal@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
(cherry picked from commit 3d9ebd4b5358d8fd4c270b516430169905c38686
 https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm)
(cherry picked from commit 2b7ef118b617be551c23e975dfe44588b180c536
 https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm)
Bug: 172318110
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Change-Id: Id6730d66306531a9031ab6f6359a825869fa1890
This commit is contained in:
Vijayanand Jitta
2021-02-12 17:14:55 +11:00
committed by Alistair Delva
parent 892f557389
commit bfed1c3081
4 changed files with 45 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
Documentation/admin-guide/kernel-parameters.txt
View File

@@ -5174,6 +5174,12 @@
growing up) the main stack are reserved for no other
mapping. Default value is 256 pages.
stack_depot_disable= [KNL]
Setting this to true through kernel command line will
disable the stack depot thereby saving the static memory
consumed by the stack hash table. By default this is set
to false.
stacktrace [FTRACE]
Enabled the stack tracer on boot up.

9
include/linux/stackdepot.h
View File

@@ -21,4 +21,13 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);
#ifdef CONFIG_STACKDEPOT
int stack_depot_init(void);
#else
static inline int stack_depot_init(void)
{
return 0;
}
#endif /* CONFIG_STACKDEPOT */
#endif

2
init/main.c
View File

@@ -99,6 +99,7 @@
#include <linux/mem_encrypt.h>
#include <linux/kcsan.h>
#include <linux/init_syscalls.h>
#include <linux/stackdepot.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -829,6 +830,7 @@ static void __init mm_init(void)
init_debug_pagealloc();
kfence_alloc_pool();
report_meminit();
stack_depot_init();
mem_init();
kmem_cache_init();
kmemleak_init();

32
lib/stackdepot.c
View File

@@ -31,6 +31,7 @@
#include <linux/stackdepot.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/memblock.h>
#define DEPOT_STACK_BITS (sizeof(depot_stack_handle_t) * 8)
@@ -145,9 +146,32 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size,
#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 bool stack_depot_disable;
static struct stack_record **stack_table;
static int __init is_stack_depot_disabled(char *str)
{
kstrtobool(str, &stack_depot_disable);
if (stack_depot_disable) {
pr_info("Stack Depot is disabled\n");
stack_table = NULL;
}
return 0;
}
early_param("stack_depot_disable", is_stack_depot_disabled);
int __init stack_depot_init(void)
{
if (!stack_depot_disable) {
size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *));
int i;
stack_table = memblock_alloc(size, size);
for (i = 0; i < STACK_HASH_SIZE; i++)
stack_table[i] = NULL;
}
return 0;
}
/* Calculate hash for a stack */
static inline u32 hash_stack(unsigned long *entries, unsigned int size)
@@ -241,7 +265,7 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
unsigned long flags;
u32 hash;
if (unlikely(nr_entries == 0))
if (unlikely(nr_entries == 0) || stack_depot_disable)
goto fast_exit;
hash = hash_stack(entries, nr_entries);