The patch titled Subject: shmem: shrink shmem_inode_info: dir_offsets in a union has been added to the -mm mm-unstable branch. Its filename is shmem-shrink-shmem_inode_info-dir_offsets-in-a-union.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/shmem-shrink-shmem_inode_info-dir_offsets-in-a-union.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: shmem: shrink shmem_inode_info: dir_offsets in a union Date: Fri, 29 Sep 2023 20:25:38 -0700 (PDT) Patch series "shmem,tmpfs: general maintenance". Mostly just cosmetic mods in mm/shmem.c, but the last two enforcing the "size=" limit better. 8/8 goes into percpu counter territory, and could stand alone. This patch (of 8): 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. Link: https://lkml.kernel.org/r/c7441dc6-f3bb-dd60-c670-9f5cbd9f266@xxxxxxxxxx Link: https://lkml.kernel.org/r/86ebb4b-c571-b9e8-27f5-cb82ec50357e@xxxxxxxxxx Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Cc: Carlos Maiolino <cem@xxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Darrick J. Wong <djwong@xxxxxxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Cc: Tim Chen <tim.c.chen@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/shmem_fs.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/include/linux/shmem_fs.h~shmem-shrink-shmem_inode_info-dir_offsets-in-a-union +++ a/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; }; _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are shmem-shrink-shmem_inode_info-dir_offsets-in-a-union.patch shmem-remove-vma-arg-from-shmem_get_folio_gfp.patch shmem-factor-shmem_falloc_wait-out-of-shmem_fault.patch shmem-trivial-tidyups-removing-extra-blank-lines-etc.patch shmem-shmem_acct_blocks-and-shmem_inode_acct_blocks.patch shmem-move-memcg-charge-out-of-shmem_add_to_page_cache.patch shmem-_add_to_page_cache-before-shmem_inode_acct_blocks.patch shmempercpu_counter-add-_limited_addfbc-limit-amount.patch