Andrew: This is a pretty basic and obvious cleanup IMO. How about a ride in
-mm?
Defining flags in terms of other flags is always confusing. Give them literal
values instead of defining them in terms of VM_flags. While we're at it, move
them to a header file in preparation for the introduction of a
SHMEM_HUGETLB flag.
Signed-off-by: Adam Litke <[email protected]>
---
include/linux/shmem_fs.h | 4 ++++
mm/shmem.c | 4 ----
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index f3c5189..3ea0b6e 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -8,6 +8,10 @@
#define SHMEM_NR_DIRECT 16
+/* These info->flags are used to handle pagein/truncate races efficiently */
+#define SHMEM_PAGEIN 0x00000001
+#define SHMEM_TRUNCATE 0x00000002
+
struct shmem_inode_info {
spinlock_t lock;
unsigned long flags;
diff --git a/mm/shmem.c b/mm/shmem.c
index 70da7a0..a9bdb0d 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -66,10 +66,6 @@
#define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
-/* info->flags needs VM_flags to handle pagein/truncate races efficiently */
-#define SHMEM_PAGEIN VM_READ
-#define SHMEM_TRUNCATE VM_WRITE
-
/* Definition to limit shmem_truncate's steps between cond_rescheds */
#define LATENCY_LIMIT 64
On Wed, 7 Feb 2007, Adam Litke wrote:
>
> Andrew: This is a pretty basic and obvious cleanup IMO. How about a ride in
> -mm?
>
> Defining flags in terms of other flags is always confusing. Give them literal
> values instead of defining them in terms of VM_flags. While we're at it, move
> them to a header file in preparation for the introduction of a
> SHMEM_HUGETLB flag.
NAK. Look further and you'll find at least VM_LOCKED and VM_ACCOUNT
also used straight in shmem info->flags: it's trying to ensure there
won't be a clash when applying VM_flags there. So you've a choice of
three ways forward, I don't mind which: (a) leave it alone, (b) add
comments, (c) define a separate set of flags for SHMEM and convert
where necessary. But NAK to this patch.
(Sorry, I'm way behind and haven't checked your earlier mails yet.)
Hugh
>
> Signed-off-by: Adam Litke <[email protected]>
> ---
>
> include/linux/shmem_fs.h | 4 ++++
> mm/shmem.c | 4 ----
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index f3c5189..3ea0b6e 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -8,6 +8,10 @@
>
> #define SHMEM_NR_DIRECT 16
>
> +/* These info->flags are used to handle pagein/truncate races efficiently */
> +#define SHMEM_PAGEIN 0x00000001
> +#define SHMEM_TRUNCATE 0x00000002
> +
> struct shmem_inode_info {
> spinlock_t lock;
> unsigned long flags;
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 70da7a0..a9bdb0d 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -66,10 +66,6 @@
>
> #define VM_ACCT(size) (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
>
> -/* info->flags needs VM_flags to handle pagein/truncate races efficiently */
> -#define SHMEM_PAGEIN VM_READ
> -#define SHMEM_TRUNCATE VM_WRITE
> -
> /* Definition to limit shmem_truncate's steps between cond_rescheds */
> #define LATENCY_LIMIT 64