From 2eae077e6e46f9046d383631145750e043820dce Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 2 Feb 2023 15:04:56 +0800 Subject: f2fs: reduce stack memory cost by using bitfield in struct f2fs_io_info This patch tries to use bitfield in struct f2fs_io_info to improve memory usage. struct f2fs_io_info { ... unsigned int need_lock:8; /* indicate we need to lock cp_rwsem */ unsigned int version:8; /* version of the node */ unsigned int submitted:1; /* indicate IO submission */ unsigned int in_list:1; /* indicate fio is in io_list */ unsigned int is_por:1; /* indicate IO is from recovery or not */ unsigned int retry:1; /* need to reallocate block address */ unsigned int encrypted:1; /* indicate file is encrypted */ unsigned int post_read:1; /* require post read */ ... }; After this patch, size of struct f2fs_io_info reduces from 136 to 120. [Nathan: fix a compile warning (single-bit-bitfield-constant-conversion)] Signed-off-by: Nathan Chancellor Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'fs/f2fs/f2fs.h') diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index f3c5f7740c1a..5449c8277339 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1210,19 +1210,19 @@ struct f2fs_io_info { struct page *encrypted_page; /* encrypted page */ struct page *compressed_page; /* compressed page */ struct list_head list; /* serialize IOs */ - bool submitted; /* indicate IO submission */ - int need_lock; /* indicate we need to lock cp_rwsem */ - bool in_list; /* indicate fio is in io_list */ - bool is_por; /* indicate IO is from recovery or not */ - bool retry; /* need to reallocate block address */ - int compr_blocks; /* # of compressed block addresses */ - bool encrypted; /* indicate file is encrypted */ - bool post_read; /* require post read */ + unsigned int compr_blocks; /* # of compressed block addresses */ + unsigned int need_lock:8; /* indicate we need to lock cp_rwsem */ + unsigned int version:8; /* version of the node */ + unsigned int submitted:1; /* indicate IO submission */ + unsigned int in_list:1; /* indicate fio is in io_list */ + unsigned int is_por:1; /* indicate IO is from recovery or not */ + unsigned int retry:1; /* need to reallocate block address */ + unsigned int encrypted:1; /* indicate file is encrypted */ + unsigned int post_read:1; /* require post read */ enum iostat_type io_type; /* io type */ struct writeback_control *io_wbc; /* writeback control */ struct bio **bio; /* bio for ipu */ sector_t *last_block; /* last block number in bio */ - unsigned char version; /* version of the node */ }; struct bio_entry { -- cgit v1.2.3