[PATCH 31/40] mm: percpu: enable per-cpu allocation tagging

From: Suren Baghdasaryan
Date: Mon May 01 2023 - 13:02:23 EST


Redefine __alloc_percpu, __alloc_percpu_gfp and __alloc_reserved_percpu
to record allocations and deallocations done by these functions.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
---
include/linux/percpu.h | 19 ++++++++----
mm/percpu.c | 66 +++++-------------------------------------
2 files changed, 22 insertions(+), 63 deletions(-)

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 1338ea2aa720..51ec257379af 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -2,12 +2,14 @@
#ifndef __LINUX_PERCPU_H
#define __LINUX_PERCPU_H

+#include <linux/alloc_tag.h>
#include <linux/mmdebug.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/pfn.h>
#include <linux/init.h>
+#include <linux/sched.h>

#include <asm/percpu.h>

@@ -116,7 +118,6 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
#endif

-extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1);
extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
extern bool is_kernel_percpu_address(unsigned long addr);

@@ -124,10 +125,15 @@ extern bool is_kernel_percpu_address(unsigned long addr);
extern void __init setup_per_cpu_areas(void);
#endif

-extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1);
-extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1);
-extern void free_percpu(void __percpu *__pdata);
-extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
+extern void __percpu *__pcpu_alloc(size_t size, size_t align, bool reserved,
+ gfp_t gfp) __alloc_size(1);
+
+#define __alloc_percpu_gfp(_size, _align, _gfp) alloc_hooks( \
+ __pcpu_alloc(_size, _align, false, _gfp), void __percpu *, NULL)
+#define __alloc_percpu(_size, _align) alloc_hooks( \
+ __pcpu_alloc(_size, _align, false, GFP_KERNEL), void __percpu *, NULL)
+#define __alloc_reserved_percpu(_size, _align) alloc_hooks( \
+ __pcpu_alloc(_size, _align, true, GFP_KERNEL), void __percpu *, NULL)

#define alloc_percpu_gfp(type, gfp) \
(typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
@@ -136,6 +142,9 @@ extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
(typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
__alignof__(type))

+extern void free_percpu(void __percpu *__pdata);
+extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
+
extern unsigned long pcpu_nr_pages(void);

#endif /* __LINUX_PERCPU_H */
diff --git a/mm/percpu.c b/mm/percpu.c
index 4e2592f2e58f..4b5cf260d8e0 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1728,7 +1728,7 @@ static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t s
#endif

/**
- * pcpu_alloc - the percpu allocator
+ * __pcpu_alloc - the percpu allocator
* @size: size of area to allocate in bytes
* @align: alignment of area (max PAGE_SIZE)
* @reserved: allocate from the reserved chunk if available
@@ -1742,8 +1742,8 @@ static void pcpu_alloc_tag_free_hook(struct pcpu_chunk *chunk, int off, size_t s
* RETURNS:
* Percpu pointer to the allocated area on success, NULL on failure.
*/
-static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,
- gfp_t gfp)
+void __percpu *__pcpu_alloc(size_t size, size_t align, bool reserved,
+ gfp_t gfp)
{
gfp_t pcpu_gfp;
bool is_atomic;
@@ -1909,6 +1909,8 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,

pcpu_memcg_post_alloc_hook(objcg, chunk, off, size);

+ pcpu_alloc_tag_alloc_hook(chunk, off, size);
+
return ptr;

fail_unlock:
@@ -1935,61 +1937,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved,

return NULL;
}
-
-/**
- * __alloc_percpu_gfp - allocate dynamic percpu area
- * @size: size of area to allocate in bytes
- * @align: alignment of area (max PAGE_SIZE)
- * @gfp: allocation flags
- *
- * Allocate zero-filled percpu area of @size bytes aligned at @align. If
- * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can
- * be called from any context but is a lot more likely to fail. If @gfp
- * has __GFP_NOWARN then no warning will be triggered on invalid or failed
- * allocation requests.
- *
- * RETURNS:
- * Percpu pointer to the allocated area on success, NULL on failure.
- */
-void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp)
-{
- return pcpu_alloc(size, align, false, gfp);
-}
-EXPORT_SYMBOL_GPL(__alloc_percpu_gfp);
-
-/**
- * __alloc_percpu - allocate dynamic percpu area
- * @size: size of area to allocate in bytes
- * @align: alignment of area (max PAGE_SIZE)
- *
- * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL).
- */
-void __percpu *__alloc_percpu(size_t size, size_t align)
-{
- return pcpu_alloc(size, align, false, GFP_KERNEL);
-}
-EXPORT_SYMBOL_GPL(__alloc_percpu);
-
-/**
- * __alloc_reserved_percpu - allocate reserved percpu area
- * @size: size of area to allocate in bytes
- * @align: alignment of area (max PAGE_SIZE)
- *
- * Allocate zero-filled percpu area of @size bytes aligned at @align
- * from reserved percpu area if arch has set it up; otherwise,
- * allocation is served from the same dynamic area. Might sleep.
- * Might trigger writeouts.
- *
- * CONTEXT:
- * Does GFP_KERNEL allocation.
- *
- * RETURNS:
- * Percpu pointer to the allocated area on success, NULL on failure.
- */
-void __percpu *__alloc_reserved_percpu(size_t size, size_t align)
-{
- return pcpu_alloc(size, align, true, GFP_KERNEL);
-}
+EXPORT_SYMBOL_GPL(__pcpu_alloc);

/**
* pcpu_balance_free - manage the amount of free chunks
@@ -2299,6 +2247,8 @@ void free_percpu(void __percpu *ptr)

size = pcpu_free_area(chunk, off);

+ pcpu_alloc_tag_free_hook(chunk, off, size);
+
pcpu_memcg_free_hook(chunk, off, size);

/*
--
2.40.1.495.gc816e09b53d-goog