From c8b33a57fba29733518d469be062ca6fea03203d Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 1 Jul 2025 19:23:53 +0200 Subject: [PATCH] btrfs: accessors: set target address at initialization The target address for the read/write can be simplified as it's the same expression for the first folio. This improves the generated code as the folio address does not have to be cached on stack. Stack usage reduction: btrfs_set_32 -8 (32 -> 24) btrfs_set_64 -8 (32 -> 24) btrfs_get_16 -8 (24 -> 16) Code size reduction: text data bss dec hex filename 1454459 115665 16088 1586212 183424 pre/btrfs.ko 1454279 115665 16088 1586032 183370 post/btrfs.ko DELTA: -180 Reviewed-by: Boris Burkov Signed-off-by: David Sterba --- fs/btrfs/accessors.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/accessors.c b/fs/btrfs/accessors.c index 8df404b5f6a33..af11f54737181 100644 --- a/fs/btrfs/accessors.c +++ b/fs/btrfs/accessors.c @@ -47,7 +47,7 @@ u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ const unsigned long idx = get_eb_folio_index(eb, member_offset);\ const unsigned long oil = get_eb_offset_in_folio(eb, \ member_offset);\ - char *kaddr = folio_address(eb->folios[idx]); \ + char *kaddr = folio_address(eb->folios[idx]) + oil; \ const int part = eb->folio_size - oil; \ u8 lebytes[sizeof(u##bits)]; \ \ @@ -57,14 +57,14 @@ u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ } \ if (INLINE_EXTENT_BUFFER_PAGES == 1 || sizeof(u##bits) == 1 || \ likely(sizeof(u##bits) <= part)) \ - return get_unaligned_le##bits(kaddr + oil); \ + return get_unaligned_le##bits(kaddr); \ \ if (sizeof(u##bits) == 2) { \ - lebytes[0] = *(kaddr + oil); \ + lebytes[0] = *kaddr; \ kaddr = folio_address(eb->folios[idx + 1]); \ lebytes[1] = *kaddr; \ } else { \ - memcpy(lebytes, kaddr + oil, part); \ + memcpy(lebytes, kaddr, part); \ kaddr = folio_address(eb->folios[idx + 1]); \ memcpy(lebytes + part, kaddr, sizeof(u##bits) - part); \ } \ @@ -77,7 +77,7 @@ void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \ const unsigned long idx = get_eb_folio_index(eb, member_offset);\ const unsigned long oil = get_eb_offset_in_folio(eb, \ member_offset);\ - char *kaddr = folio_address(eb->folios[idx]); \ + char *kaddr = folio_address(eb->folios[idx]) + oil; \ const int part = eb->folio_size - oil; \ u8 lebytes[sizeof(u##bits)]; \ \ @@ -87,16 +87,16 @@ void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr, \ } \ if (INLINE_EXTENT_BUFFER_PAGES == 1 || sizeof(u##bits) == 1 || \ likely(sizeof(u##bits) <= part)) { \ - put_unaligned_le##bits(val, kaddr + oil); \ + put_unaligned_le##bits(val, kaddr); \ return; \ } \ put_unaligned_le##bits(val, lebytes); \ if (sizeof(u##bits) == 2) { \ - *(kaddr + oil) = lebytes[0]; \ + *kaddr = lebytes[0]; \ kaddr = folio_address(eb->folios[idx + 1]); \ *kaddr = lebytes[1]; \ } else { \ - memcpy(kaddr + oil, lebytes, part); \ + memcpy(kaddr, lebytes, part); \ kaddr = folio_address(eb->folios[idx + 1]); \ memcpy(kaddr, lebytes + part, sizeof(u##bits) - part); \ } \ -- 2.47.2