Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754767AbdCJDYI (ORCPT ); Thu, 9 Mar 2017 22:24:08 -0500 Received: from mail-io0-f195.google.com ([209.85.223.195]:36388 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750816AbdCJDYH (ORCPT ); Thu, 9 Mar 2017 22:24:07 -0500 Subject: Re: [f2fs-dev] [PATCH] f2fs: skip scanning free nid bitmap of full NAT blocks To: Chao Yu , jaegeuk@kernel.org References: <20170301090907.82629-1-yuchao0@huawei.com> Cc: chao@kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Kinglong Mee From: Kinglong Mee Message-ID: <4ac60332-bc04-f398-3746-4ff5dbe53887@gmail.com> Date: Fri, 10 Mar 2017 11:23:57 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20170301090907.82629-1-yuchao0@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5523 Lines: 162 On 3/1/2017 17:09, Chao Yu wrote: > This patch adds to account free nids for each NAT blocks, and while > scanning all free nid bitmap, do check count and skip lookuping in > full NAT block. > > Signed-off-by: Chao Yu > --- > fs/f2fs/debug.c | 1 + > fs/f2fs/f2fs.h | 2 ++ > fs/f2fs/node.c | 34 ++++++++++++++++++++++++++++------ > 3 files changed, 31 insertions(+), 6 deletions(-) > > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c > index a77df377e2e8..ee2d0a485fc3 100644 > --- a/fs/f2fs/debug.c > +++ b/fs/f2fs/debug.c > @@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi) > si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS); > si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE; > si->base_mem += NM_I(sbi)->nat_blocks / 8; > + si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short); > > get_cache: > si->cache_mem = 0; > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 7e2924981eeb..c0b33719dfa9 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -557,6 +557,8 @@ struct f2fs_nm_info { > struct mutex build_lock; /* lock for build free nids */ > unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE]; > unsigned char *nat_block_bitmap; > + unsigned short *free_nid_count; /* free nid count of NAT block */ > + spinlock_t free_nid_lock; /* protect updating of nid count */ > Sorry for my reply so late. Is the free_nid_lock needed here? The free_nid_count should be protected as free_nid_bitmap, but there isn't any lock for free_nid_bitmap. How about atomic? The free node ids management seems a little complex now. thanks, Kinglong Mee > /* for checkpoint */ > char *nat_bitmap; /* NAT bitmap pointer */ > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 94967171dee8..1a759d45b7e4 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) > kmem_cache_free(free_nid_slab, i); > } > > -void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set) > +void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, > + bool set, bool build) > { > struct f2fs_nm_info *nm_i = NM_I(sbi); > unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); > @@ -1836,6 +1837,13 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set) > set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > else > clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > + > + spin_lock(&nm_i->free_nid_lock); > + if (set) > + nm_i->free_nid_count[nat_ofs]++; > + else if (!build) > + nm_i->free_nid_count[nat_ofs]--; > + spin_unlock(&nm_i->free_nid_lock); > } > > static void scan_nat_page(struct f2fs_sb_info *sbi, > @@ -1847,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, > unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid); > int i; > > + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) > + return; > + > set_bit_le(nat_ofs, nm_i->nat_block_bitmap); > > i = start_nid % NAT_ENTRY_PER_BLOCK; > @@ -1861,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, > f2fs_bug_on(sbi, blk_addr == NEW_ADDR); > if (blk_addr == NULL_ADDR) > freed = add_free_nid(sbi, start_nid, true); > - update_free_nid_bitmap(sbi, start_nid, freed); > + update_free_nid_bitmap(sbi, start_nid, freed, true); > } > } > > @@ -1877,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi) > for (i = 0; i < nm_i->nat_blocks; i++) { > if (!test_bit_le(i, nm_i->nat_block_bitmap)) > continue; > + if (!nm_i->free_nid_count[i]) > + continue; > for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) { > nid_t nid; > > @@ -2081,7 +2094,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid) > __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false); > nm_i->available_nids--; > > - update_free_nid_bitmap(sbi, *nid, false); > + update_free_nid_bitmap(sbi, *nid, false, false); > > spin_unlock(&nm_i->nid_list_lock); > return true; > @@ -2137,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) > > nm_i->available_nids++; > > - update_free_nid_bitmap(sbi, nid, true); > + update_free_nid_bitmap(sbi, nid, true, false); > > spin_unlock(&nm_i->nid_list_lock); > > @@ -2467,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, > add_free_nid(sbi, nid, false); > spin_lock(&NM_I(sbi)->nid_list_lock); > NM_I(sbi)->available_nids++; > - update_free_nid_bitmap(sbi, nid, true); > + update_free_nid_bitmap(sbi, nid, true, false); > spin_unlock(&NM_I(sbi)->nid_list_lock); > } else { > spin_lock(&NM_I(sbi)->nid_list_lock); > - update_free_nid_bitmap(sbi, nid, false); > + update_free_nid_bitmap(sbi, nid, false, false); > spin_unlock(&NM_I(sbi)->nid_list_lock); > } > } > @@ -2651,6 +2664,14 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi) > GFP_KERNEL); > if (!nm_i->nat_block_bitmap) > return -ENOMEM; > + > + nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks * > + sizeof(unsigned short), GFP_KERNEL); > + if (!nm_i->free_nid_count) > + return -ENOMEM; > + > + spin_lock_init(&nm_i->free_nid_lock); > + > return 0; > } > > @@ -2730,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi) > > kvfree(nm_i->nat_block_bitmap); > kvfree(nm_i->free_nid_bitmap); > + kvfree(nm_i->free_nid_count); > > kfree(nm_i->nat_bitmap); > kfree(nm_i->nat_bits); >