* [f2fs-dev] [PATCH] f2fs: optimize __update_nat_bits [not found] <CGME20171030072058epcas2p153d0b5c921ea4d3f3da6c6fd9baa5124@epcas2p1.samsung.com> @ 2017-10-30 7:19 ` Fan Li 2017-10-30 9:39 ` Chao Yu 0 siblings, 1 reply; 2+ messages in thread From: Fan Li @ 2017-10-30 7:19 UTC (permalink / raw) To: 'Chao Yu', jaegeuk; +Cc: linux-kernel, linux-f2fs-devel Make three modification for __update_nat_bits: 1. Take the codes of dealing the nat with nid 0 out of the loop Such nat only needs to be dealt with once at beginning. 2. Use " nat_index == 0" instead of " start_nid == 0" to decide if it's the first nat block It's better that we don't assume @start_nid is the first nid of the nat block it's in. 3. Use " if (nat_blk->entries[i].block_addr != NULL_ADDR)" to explicitly comfirm the value of block_addr use constant to make sure the codes is right, even if the value of NULL_ADDR changes. Signed-off-by: Fan li <fanofcode.li@samsung.com> --- fs/f2fs/node.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index ac629d6..b97a031 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2407,15 +2407,17 @@ static void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid, unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK; struct f2fs_nat_block *nat_blk = page_address(page); int valid = 0; - int i; + int i = 0; if (!enabled_nat_bits(sbi, NULL)) return; - for (i = 0; i < NAT_ENTRY_PER_BLOCK; i++) { - if (start_nid == 0 && i == 0) - valid++; - if (nat_blk->entries[i].block_addr) + if (nat_index == 0) { + valid = 1; + i = 1; + } + for (; i < NAT_ENTRY_PER_BLOCK; i++) { + if (nat_blk->entries[i].block_addr != NULL_ADDR) valid++; } if (valid == 0) { -- 2.7.4 ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [f2fs-dev] [PATCH] f2fs: optimize __update_nat_bits 2017-10-30 7:19 ` [f2fs-dev] [PATCH] f2fs: optimize __update_nat_bits Fan Li @ 2017-10-30 9:39 ` Chao Yu 0 siblings, 0 replies; 2+ messages in thread From: Chao Yu @ 2017-10-30 9:39 UTC (permalink / raw) To: Fan Li, jaegeuk; +Cc: linux-kernel, linux-f2fs-devel On 2017/10/30 15:19, Fan Li wrote: > Make three modification for __update_nat_bits: > 1. Take the codes of dealing the nat with nid 0 out of the loop > Such nat only needs to be dealt with once at beginning. > 2. Use " nat_index == 0" instead of " start_nid == 0" to decide if it's the first nat block > It's better that we don't assume @start_nid is the first nid of the nat block it's in. > 3. Use " if (nat_blk->entries[i].block_addr != NULL_ADDR)" to explicitly comfirm the value of block_addr > use constant to make sure the codes is right, even if the value of NULL_ADDR changes. > > Signed-off-by: Fan li <fanofcode.li@samsung.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Thanks, > --- > fs/f2fs/node.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index ac629d6..b97a031 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -2407,15 +2407,17 @@ static void __update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid, > unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK; > struct f2fs_nat_block *nat_blk = page_address(page); > int valid = 0; > - int i; > + int i = 0; > > if (!enabled_nat_bits(sbi, NULL)) > return; > > - for (i = 0; i < NAT_ENTRY_PER_BLOCK; i++) { > - if (start_nid == 0 && i == 0) > - valid++; > - if (nat_blk->entries[i].block_addr) > + if (nat_index == 0) { > + valid = 1; > + i = 1; > + } > + for (; i < NAT_ENTRY_PER_BLOCK; i++) { > + if (nat_blk->entries[i].block_addr != NULL_ADDR) > valid++; > } > if (valid == 0) { > -- > 2.7.4 > > > ^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-10-30 7:19 ` [f2fs-dev] [PATCH] f2fs: optimize __update_nat_bits Fan Li
2017-10-30 9:39 ` Chao Yu
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