From 84cda1a6087d522548b7c8baac886c8e476be152 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 5 Jan 2024 16:05:55 +1030 Subject: btrfs: cache folio size and shift in extent_buffer After the conversion to folio interfaces (but without the patch to enable larger folio allocation), there is an LTP report about observable performance drop on metadata heavy operations. https://lore.kernel.org/linux-btrfs/202312221750.571925bd-oliver.sang@intel.com/ This drop is caused by the extra code of calculating the folio_size()/folio_shift(), instead of the old hard coded PAGE_SIZE/PAGE_SHIFT. To slightly reduce the overhead, just cache both folio_size and folio_shift in extent_buffer. The two new members (u32 folio_size and u8 folio_shift) are stored inside the holes of extent_buffer. folio_size is shared with len, which is reduced to u32. The size of eb does not change. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/accessors.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'fs/btrfs/accessors.c') diff --git a/fs/btrfs/accessors.c b/fs/btrfs/accessors.c index 1925a0919ca6..6eb850ad37d2 100644 --- a/fs/btrfs/accessors.c +++ b/fs/btrfs/accessors.c @@ -63,8 +63,8 @@ u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \ const unsigned long oil = get_eb_offset_in_folio(token->eb, \ member_offset);\ - const int unit_size = folio_size(token->eb->folios[0]); \ - const int unit_shift = folio_shift(token->eb->folios[0]); \ + const int unit_size = token->eb->folio_size; \ + const int unit_shift = token->eb->folio_shift; \ const int size = sizeof(u##bits); \ u8 lebytes[sizeof(u##bits)]; \ const int part = unit_size - oil; \ @@ -94,7 +94,7 @@ 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);\ - const int unit_size = folio_size(eb->folios[0]); \ + const int unit_size = eb->folio_size; \ char *kaddr = folio_address(eb->folios[idx]); \ const int size = sizeof(u##bits); \ const int part = unit_size - oil; \ @@ -117,8 +117,8 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token, \ const unsigned long idx = get_eb_folio_index(token->eb, member_offset); \ const unsigned long oil = get_eb_offset_in_folio(token->eb, \ member_offset);\ - const int unit_size = folio_size(token->eb->folios[0]); \ - const int unit_shift = folio_shift(token->eb->folios[0]); \ + const int unit_size = token->eb->folio_size; \ + const int unit_shift = token->eb->folio_shift; \ const int size = sizeof(u##bits); \ u8 lebytes[sizeof(u##bits)]; \ const int part = unit_size - oil; \ @@ -151,7 +151,7 @@ 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);\ - const int unit_size = folio_size(eb->folios[0]); \ + const int unit_size = eb->folio_size; \ char *kaddr = folio_address(eb->folios[idx]); \ const int size = sizeof(u##bits); \ const int part = unit_size - oil; \ -- cgit