| Message ID | 86ebb4b-c571-b9e8-27f5-cb82ec50357e@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | shmem,tmpfs: general maintenance | expand |
On Fri, Sep 29, 2023 at 08:25:38PM -0700, Hugh Dickins wrote: > Shave 32 bytes off (the 64-bit) shmem_inode_info. There was a 4-byte > pahole after stop_eviction, better filled by fsflags. And the 24-byte > dir_offsets can only be used by directories, whereas shrinklist and > swaplist only by shmem_mapping() inodes (regular files or long symlinks): > so put those into a union. No change in mm/shmem.c is required for this. > > Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> > --- > include/linux/shmem_fs.h | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > index 6b0c626620f5..2caa6b86106a 100644 > --- a/include/linux/shmem_fs.h > +++ b/include/linux/shmem_fs.h > @@ -23,18 +23,22 @@ struct shmem_inode_info { > unsigned long flags; > unsigned long alloced; /* data pages alloced to file */ > unsigned long swapped; /* subtotal assigned to swap */ > - pgoff_t fallocend; /* highest fallocate endindex */ > - struct list_head shrinklist; /* shrinkable hpage inodes */ > - struct list_head swaplist; /* chain of maybes on swap */ > + union { > + struct offset_ctx dir_offsets; /* stable directory offsets */ > + struct { > + struct list_head shrinklist; /* shrinkable hpage inodes */ > + struct list_head swaplist; /* chain of maybes on swap */ > + }; > + }; > + struct timespec64 i_crtime; /* file creation time */ > struct shared_policy policy; /* NUMA memory alloc policy */ > struct simple_xattrs xattrs; /* list of xattrs */ > + pgoff_t fallocend; /* highest fallocate endindex */ > + unsigned int fsflags; /* for FS_IOC_[SG]ETFLAGS */ > atomic_t stop_eviction; /* hold when working on inode */ > - struct timespec64 i_crtime; /* file creation time */ > - unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */ > #ifdef CONFIG_TMPFS_QUOTA > struct dquot *i_dquot[MAXQUOTAS]; > #endif > - struct offset_ctx dir_offsets; /* stable entry offsets */ > struct inode vfs_inode; > }; > > -- > 2.35.3 >
On Fri 29-09-23 20:25:38, Hugh Dickins wrote: > Shave 32 bytes off (the 64-bit) shmem_inode_info. There was a 4-byte > pahole after stop_eviction, better filled by fsflags. And the 24-byte > dir_offsets can only be used by directories, whereas shrinklist and > swaplist only by shmem_mapping() inodes (regular files or long symlinks): > so put those into a union. No change in mm/shmem.c is required for this. > > Signed-off-by: Hugh Dickins <hughd@google.com> Looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > include/linux/shmem_fs.h | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > index 6b0c626620f5..2caa6b86106a 100644 > --- a/include/linux/shmem_fs.h > +++ b/include/linux/shmem_fs.h > @@ -23,18 +23,22 @@ struct shmem_inode_info { > unsigned long flags; > unsigned long alloced; /* data pages alloced to file */ > unsigned long swapped; /* subtotal assigned to swap */ > - pgoff_t fallocend; /* highest fallocate endindex */ > - struct list_head shrinklist; /* shrinkable hpage inodes */ > - struct list_head swaplist; /* chain of maybes on swap */ > + union { > + struct offset_ctx dir_offsets; /* stable directory offsets */ > + struct { > + struct list_head shrinklist; /* shrinkable hpage inodes */ > + struct list_head swaplist; /* chain of maybes on swap */ > + }; > + }; > + struct timespec64 i_crtime; /* file creation time */ > struct shared_policy policy; /* NUMA memory alloc policy */ > struct simple_xattrs xattrs; /* list of xattrs */ > + pgoff_t fallocend; /* highest fallocate endindex */ > + unsigned int fsflags; /* for FS_IOC_[SG]ETFLAGS */ > atomic_t stop_eviction; /* hold when working on inode */ > - struct timespec64 i_crtime; /* file creation time */ > - unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */ > #ifdef CONFIG_TMPFS_QUOTA > struct dquot *i_dquot[MAXQUOTAS]; > #endif > - struct offset_ctx dir_offsets; /* stable entry offsets */ > struct inode vfs_inode; > }; > > -- > 2.35.3 >
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 6b0c626620f5..2caa6b86106a 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -23,18 +23,22 @@ struct shmem_inode_info { unsigned long flags; unsigned long alloced; /* data pages alloced to file */ unsigned long swapped; /* subtotal assigned to swap */ - pgoff_t fallocend; /* highest fallocate endindex */ - struct list_head shrinklist; /* shrinkable hpage inodes */ - struct list_head swaplist; /* chain of maybes on swap */ + union { + struct offset_ctx dir_offsets; /* stable directory offsets */ + struct { + struct list_head shrinklist; /* shrinkable hpage inodes */ + struct list_head swaplist; /* chain of maybes on swap */ + }; + }; + struct timespec64 i_crtime; /* file creation time */ struct shared_policy policy; /* NUMA memory alloc policy */ struct simple_xattrs xattrs; /* list of xattrs */ + pgoff_t fallocend; /* highest fallocate endindex */ + unsigned int fsflags; /* for FS_IOC_[SG]ETFLAGS */ atomic_t stop_eviction; /* hold when working on inode */ - struct timespec64 i_crtime; /* file creation time */ - unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */ #ifdef CONFIG_TMPFS_QUOTA struct dquot *i_dquot[MAXQUOTAS]; #endif - struct offset_ctx dir_offsets; /* stable entry offsets */ struct inode vfs_inode; };
Shave 32 bytes off (the 64-bit) shmem_inode_info. There was a 4-byte pahole after stop_eviction, better filled by fsflags. And the 24-byte dir_offsets can only be used by directories, whereas shrinklist and swaplist only by shmem_mapping() inodes (regular files or long symlinks): so put those into a union. No change in mm/shmem.c is required for this. Signed-off-by: Hugh Dickins <hughd@google.com> --- include/linux/shmem_fs.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)