From ac75b922bb67cc8edb52006c9346dc0ca91d04c8 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 28 May 2026 18:31:45 +0100 Subject: buffer: Remove b_end_io This shrinks buffer_head by 8 bytes, letting us pack more buffer heads per slab. With a Debian config, it shrinks from 104 bytes to 96 bytes which is 42 objects per 4KiB page rather than 39, a 7% reduction in the amount of memory used. Signed-off-by: Matthew Wilcox (Oracle) Link: https://patch.msgid.link/20260528173150.1093780-33-willy@infradead.org Reviewed-by: Jan Kara Signed-off-by: Christian Brauner (Amutable) --- include/linux/buffer_head.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 7629130d42c4..1ee56c9f2327 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -46,7 +46,6 @@ enum bh_state_bits { struct page; struct buffer_head; struct address_space; -typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate); /* * Historically, a buffer_head was used to map a single block @@ -70,8 +69,7 @@ struct buffer_head { char *b_data; /* pointer to data within the page */ struct block_device *b_bdev; - bh_end_io_t *b_end_io; /* I/O completion */ - void *b_private; /* reserved for b_end_io */ + void *b_private; /* reserved for bio_end_io */ struct list_head b_assoc_buffers; /* associated with another mapping */ struct mapping_metadata_bhs *b_mmb; /* head of the list of metadata bhs * this buffer is associated with */ -- cgit v1.2.3