mm: add comments for allocation helpers explaining why they are macros

A number of allocation helper functions were converted into macros to
account them at the call sites.  Add a comment for each converted
allocation helper explaining why it has to be a macro and why we typecast
the return value wherever required.  The patch also moves
acpi_os_acquire_object() closer to other allocation helpers to group them
together under the same comment.  The patch has no functional changes.

Link: https://lkml.kernel.org/r/20240703174225.3891393-1-surenb@google.com
Fixes: 2c321f3f70bc ("mm: change inlined allocation helpers to account at the call site")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index b17a9eb9b1488b07e6028b5fc60476ef47c1e356..49862c95b224839193a51323812d1823ac549fb1 100644 (file)
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -46,6 +46,10 @@ static inline void nfs_add_stats(const struct inode *inode,
        nfs_add_server_stats(NFS_SERVER(inode), stat, addend);
 }
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag).
+ */
 #define nfs_alloc_iostats()    alloc_percpu(struct nfs_iostats)
 
 static inline void nfs_free_iostats(struct nfs_iostats __percpu *stats)

diff --git a/include/acpi/platform/aclinuxex.h b/include/acpi/platform/aclinuxex.h
index 62cac266a1c89e6eb6adf6fcdb961ae42821be58..eeff40295b4b5dd4af5e8b9eaa62dbadb51d533f 100644 (file)
--- a/include/acpi/platform/aclinuxex.h
+++ b/include/acpi/platform/aclinuxex.h
@@ -46,6 +46,9 @@ acpi_status acpi_os_terminate(void);
  * Interrupts are off during resume, just like they are for boot.
  * However, boot has  (system_state != SYSTEM_RUNNING)
  * to quiet __might_sleep() in kmalloc() and resume does not.
+ *
+ * These specialized allocators have to be macros for their allocations to be
+ * accounted separately (to have separate alloc_tag).
  */
 #define acpi_os_allocate(_size)        \
                kmalloc(_size, irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL)
@@ -53,14 +56,14 @@ acpi_status acpi_os_terminate(void);
 #define acpi_os_allocate_zeroed(_size) \
                kzalloc(_size, irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL)
 
+#define acpi_os_acquire_object(_cache) \
+               kmem_cache_zalloc(_cache, irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL)
+
 static inline void acpi_os_free(void *memory)
 {
        kfree(memory);
 }
 
-#define acpi_os_acquire_object(_cache) \
-               kmem_cache_zalloc(_cache, irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL)
-
 static inline acpi_thread_id acpi_os_get_thread_id(void)
 {
        return (acpi_thread_id) (unsigned long)current;

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b8637555c9c233d740406125297a4277464dcc91..50b82ff4551a03b15fffc50a2319fe51e04e421f 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2261,6 +2261,10 @@ void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
                                    size_t align, gfp_t flags);
 #else
+/*
+ * These specialized allocators have to be macros for their allocations to be
+ * accounted separately (to have separate alloc_tag).
+ */
 #define bpf_map_kmalloc_node(_map, _size, _flags, _node)       \
                kmalloc_node(_size, _flags, _node)
 #define bpf_map_kzalloc(_map, _size, _flags)                   \

diff --git a/include/linux/dma-fence-chain.h b/include/linux/dma-fence-chain.h
index ad9e2506c2f40180f7995d65a55fb76bcaf50d9a..68c3c1e41014045ea4cbfef321b9f0207f53621e 100644 (file)
--- a/include/linux/dma-fence-chain.h
+++ b/include/linux/dma-fence-chain.h
@@ -85,6 +85,10 @@ dma_fence_chain_contained(struct dma_fence *fence)
  * dma_fence_chain_alloc
  *
  * Returns a new struct dma_fence_chain object or NULL on failure.
+ *
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag). The typecast is
+ * intentional to enforce typesafety.
  */
 #define dma_fence_chain_alloc()        \
                ((struct dma_fence_chain *)kmalloc(sizeof(struct dma_fence_chain), GFP_KERNEL))

diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h
index eec2592dec12831e4c6e049bf011fb148fa0082f..99a3edb6cf0702a426690ba9d8252e4061835a5e 100644 (file)
--- a/include/linux/hid_bpf.h
+++ b/include/linux/hid_bpf.h
@@ -152,6 +152,11 @@ static inline int hid_bpf_connect_device(struct hid_device *hdev) { return 0; }
 static inline void hid_bpf_disconnect_device(struct hid_device *hdev) {}
 static inline void hid_bpf_destroy_device(struct hid_device *hid) {}
 static inline void hid_bpf_device_init(struct hid_device *hid) {}
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag). The typecast is
+ * intentional to enforce typesafety.
+ */
 #define call_hid_bpf_rdesc_fixup(_hdev, _rdesc, _size) \
                ((u8 *)kmemdup(_rdesc, *(_size), GFP_KERNEL))
 

diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index ab04c1c27fae384dd0fb21e285dd831abde4af71..a280f42c8c76219380d253ca93bdf01a543919b4 100644 (file)
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1588,6 +1588,11 @@ void jbd2_journal_put_journal_head(struct journal_head *jh);
  */
 extern struct kmem_cache *jbd2_handle_cache;
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag). The typecast is
+ * intentional to enforce typesafety.
+ */
 #define jbd2_alloc_handle(_gfp_flags)  \
                ((handle_t *)kmem_cache_zalloc(jbd2_handle_cache, _gfp_flags))
 
@@ -1602,6 +1607,11 @@ static inline void jbd2_free_handle(handle_t *handle)
  */
 extern struct kmem_cache *jbd2_inode_cache;
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag). The typecast is
+ * intentional to enforce typesafety.
+ */
 #define jbd2_alloc_inode(_gfp_flags)   \
                ((struct jbd2_inode *)kmem_cache_alloc(jbd2_inode_cache, _gfp_flags))
 

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1c2902eaebd376c3e6a9212ce5d6f9edb87a3bfa..fd51f2de51da232d11952412771332272cd081d7 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3400,6 +3400,10 @@ static inline struct page *__dev_alloc_pages_noprof(gfp_t gfp_mask,
 }
 #define __dev_alloc_pages(...) alloc_hooks(__dev_alloc_pages_noprof(__VA_ARGS__))
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag).
+ */
 #define dev_alloc_pages(_order) __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, _order)
 
 /**
@@ -3416,6 +3420,10 @@ static inline struct page *__dev_alloc_page_noprof(gfp_t gfp_mask)
 }
 #define __dev_alloc_page(...)  alloc_hooks(__dev_alloc_page_noprof(__VA_ARGS__))
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag).
+ */
 #define dev_alloc_page()       dev_alloc_pages(0)
 
 /**

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index c9efda9df285563dd6380dbc160d77117462c54c..d9b03e0746e7a4db568aadb9f4e15789abddceb9 100644 (file)
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -414,6 +414,11 @@ void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
 int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
                         struct sk_msg *msg);
 
+/*
+ * This specialized allocator has to be a macro for its allocations to be
+ * accounted separately (to have a separate alloc_tag). The typecast is
+ * intentional to enforce typesafety.
+ */
 #define sk_psock_init_link()   \
                ((struct sk_psock_link *)kzalloc(sizeof(struct sk_psock_link),  \
                                                 GFP_ATOMIC | __GFP_NOWARN))