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
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------------------------------------------------------
From: Yogesh Lal <ylal@xxxxxxxxxxxxxx>
Subject: lib: stackdepot: add support to configure STACK_HASH_SIZE
Use CONFIG_STACK_HASH_ORDER to configure STACK_HASH_SIZE.
Aim is to have configurable value for STACK_HASH_SIZE,
so depend on use case one can configure it.
One example is of Page Owner, CONFIG_PAGE_OWNER works only if
page_owner=on via kernel parameter on CONFIG_PAGE_OWNER configured system.
Thus, unless admin enable it via command line option, the stackdepot will
just waste 8M memory without any customer.
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/1611749198-24316-1-git-send-email-vjitta@xxxxxxxxxxxxxx
Signed-off-by: Yogesh Lal <ylal@xxxxxxxxxxxxxx>
Signed-off-by: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Signed-off-by: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/Kconfig | 9 +++++++++
lib/stackdepot.c | 3 +--
2 files changed, 10 insertions(+), 2 deletions(-)
--- a/lib/Kconfig~lib-stackdepot-add-support-to-configure-stack_hash_size
+++ a/lib/Kconfig
@@ -651,6 +651,15 @@ config STACKDEPOT
bool
select STACKTRACE
+config STACK_HASH_ORDER
+ int "stack depot hash size (12 => 4KB, 20 => 1024KB)"
+ range 12 20
+ default 20
+ depends on STACKDEPOT
+ help
+ Select the hash size as a power of 2 for the stackdepot hash table.
+ Choose a lower value to reduce the memory impact.
+
config SBITMAP
bool
--- a/lib/stackdepot.c~lib-stackdepot-add-support-to-configure-stack_hash_size
+++ a/lib/stackdepot.c
@@ -141,8 +141,7 @@ static struct stack_record *depot_alloc_
return stack;
}
-#define STACK_HASH_ORDER 20
-#define STACK_HASH_SIZE (1L << STACK_HASH_ORDER)
+#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER)
#define STACK_HASH_MASK (STACK_HASH_SIZE - 1)
#define STACK_HASH_SEED 0x9747b28c
_
Patches currently in -mm which might be from ylal@xxxxxxxxxxxxxx are
lib-stackdepot-add-support-to-configure-stack_hash_size.patch
