[1/3] fuse: on 64-bit store time in d_fsdata directly
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Message ID 20190822000933.180870-1-khazhy@google.com
State New
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Series
  • [1/3] fuse: on 64-bit store time in d_fsdata directly
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Commit Message

Khazhismel Kumykov Aug. 22, 2019, 12:09 a.m. UTC
Implements the optimization noted in f75fdf22b0a8 ("fuse: don't use
->d_time"), as the additional memory can be significant. (In particular,
on SLAB configurations this 8-byte alloc becomes 32 bytes). Per-dentry,
this can consume significant memory.

Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
---
 fs/fuse/dir.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Shakeel Butt Aug. 22, 2019, 12:17 a.m. UTC | #1
On Wed, Aug 21, 2019 at 5:09 PM Khazhismel Kumykov <khazhy@google.com> wrote:
>
> Implements the optimization noted in f75fdf22b0a8 ("fuse: don't use
> ->d_time"), as the additional memory can be significant. (In particular,
> on SLAB configurations this 8-byte alloc becomes 32 bytes). Per-dentry,
> this can consume significant memory.
>
> Signed-off-by: Khazhismel Kumykov <khazhy@google.com>

Actually we are seeing this in production where a job creating a lot
of fuse files cause a lot of extra system level overhead.

Reviewed-by: Shakeel Butt <shakeelb@google.com>

> ---
>  fs/fuse/dir.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
> index dd0f64f7bc06..f9c59a296568 100644
> --- a/fs/fuse/dir.c
> +++ b/fs/fuse/dir.c
> @@ -24,6 +24,18 @@ static void fuse_advise_use_readdirplus(struct inode *dir)
>         set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
>  }
>
> +#if BITS_PER_LONG >= 64
> +static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
> +{
> +       entry->d_fsdata = (void *) time;
> +}
> +
> +static inline u64 fuse_dentry_time(struct dentry *entry)
> +{
> +       return (u64)entry->d_fsdata;
> +}
> +
> +#else
>  union fuse_dentry {
>         u64 time;
>         struct rcu_head rcu;
> @@ -38,6 +50,7 @@ static inline u64 fuse_dentry_time(struct dentry *entry)
>  {
>         return ((union fuse_dentry *) entry->d_fsdata)->time;
>  }
> +#endif
>
>  /*
>   * FUSE caches dentries and attributes with separate timeout.  The
> @@ -242,6 +255,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
>         goto out;
>  }
>
> +#if BITS_PER_LONG < 64
>  static int fuse_dentry_init(struct dentry *dentry)
>  {
>         dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL);
> @@ -254,16 +268,21 @@ static void fuse_dentry_release(struct dentry *dentry)
>
>         kfree_rcu(fd, rcu);
>  }
> +#endif
>
>  const struct dentry_operations fuse_dentry_operations = {
>         .d_revalidate   = fuse_dentry_revalidate,
> +#if BITS_PER_LONG < 64
>         .d_init         = fuse_dentry_init,
>         .d_release      = fuse_dentry_release,
> +#endif
>  };
>
>  const struct dentry_operations fuse_root_dentry_operations = {
> +#if BITS_PER_LONG < 64
>         .d_init         = fuse_dentry_init,
>         .d_release      = fuse_dentry_release,
> +#endif
>  };
>
>  int fuse_valid_type(int m)
> --
> 2.23.0.187.g17f5b7556c-goog
>

Patch
diff mbox series

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index dd0f64f7bc06..f9c59a296568 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -24,6 +24,18 @@  static void fuse_advise_use_readdirplus(struct inode *dir)
 	set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
 }
 
+#if BITS_PER_LONG >= 64
+static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
+{
+	entry->d_fsdata = (void *) time;
+}
+
+static inline u64 fuse_dentry_time(struct dentry *entry)
+{
+	return (u64)entry->d_fsdata;
+}
+
+#else
 union fuse_dentry {
 	u64 time;
 	struct rcu_head rcu;
@@ -38,6 +50,7 @@  static inline u64 fuse_dentry_time(struct dentry *entry)
 {
 	return ((union fuse_dentry *) entry->d_fsdata)->time;
 }
+#endif
 
 /*
  * FUSE caches dentries and attributes with separate timeout.  The
@@ -242,6 +255,7 @@  static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 	goto out;
 }
 
+#if BITS_PER_LONG < 64
 static int fuse_dentry_init(struct dentry *dentry)
 {
 	dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL);
@@ -254,16 +268,21 @@  static void fuse_dentry_release(struct dentry *dentry)
 
 	kfree_rcu(fd, rcu);
 }
+#endif
 
 const struct dentry_operations fuse_dentry_operations = {
 	.d_revalidate	= fuse_dentry_revalidate,
+#if BITS_PER_LONG < 64
 	.d_init		= fuse_dentry_init,
 	.d_release	= fuse_dentry_release,
+#endif
 };
 
 const struct dentry_operations fuse_root_dentry_operations = {
+#if BITS_PER_LONG < 64
 	.d_init		= fuse_dentry_init,
 	.d_release	= fuse_dentry_release,
+#endif
 };
 
 int fuse_valid_type(int m)