Re: [PATCH] f2fs: split bio cache

From: Chao Yu
Date: Thu May 11 2017 - 23:20:27 EST

On 2017/5/11 10:35, Jaegeuk Kim wrote:
> On 05/11, Chao Yu wrote:
>> On 2017/5/11 7:50, Jaegeuk Kim wrote:
>>> On 05/09, Chao Yu wrote:
>>>> Hi Jaegeuk,
>>>>
>>>> On 2017/5/9 5:23, Jaegeuk Kim wrote:
>>>>> Hi Chao,
>>>>>
>>>>> I can't see a strong reason to split meta from data/node and rename the existing
>>>>> function names. Instead, how about keeping the existing one while adding some
>>>>> page types to deal with log types?
>>>>
>>>> Hmm.. before write this patch, I have thought about this implementation which
>>>> adds HOT_DATA/WARM_DATA/.. into page_type enum, but the final target is making
>>>> different temperature log-header being with independent bio cache, io lock, and
>>>> io list, eliminating interaction of different temperature IOs, also expanding
>>>> f2fs' scalability when adding more log-headers. If we don't split meta from
>>>> data/node, it's a little bit hard to approach this. What do you think?
>>>
>>> I submitted clean-up patches. How about this on top of them?
>>
>> After splitting, bio caches is connected to log-header, so why not moving bio
>> cache into log-header (SM_I(sbi)->curseg_array)? after the merging:
>> - we could avoid redundant enum. e.g. temp_type, page_type::{DATA/NODE}, since
>> we have seg_type enum instead.
>> - once we add special log-header like journal log or random IO log making
>> DATA/NODE and HOT/WARM/COLD non-orthogonalization, we just need to change few
>> codes to adjust it.
>
> Well, I perfer to keep block allocation and IO control in a separate way as is.
> Moreover, I don't think performance gain would be large enough comparing to what
> we need to change both of whole flows.

Alright, let's use your implementation. ;)

Could you resend this patch? and then I will rebase my patch on this one.

Thanks,

>
> Thanks,
>
>>
>> How do you think?
>>
>> Thanks,
>>
>>>
>>> ---
>>> fs/f2fs/data.c | 51 +++++++++++++++++++++++++++++++++------------
>>> fs/f2fs/f2fs.h | 10 ++++++++-
>>> fs/f2fs/gc.c | 2 ++
>>> fs/f2fs/segment.c | 24 +++++++++++++++------
>>> fs/f2fs/segment.h | 4 ++++
>>> fs/f2fs/super.c | 21 ++++++++++++++++---
>>> include/trace/events/f2fs.h | 14 ++++++++++++-
>>> 7 files changed, 102 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index 06bb2042385e..49b7e3918484 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -282,21 +282,30 @@ static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
>>> nid_t ino, pgoff_t idx, enum page_type type)
>>> {
>>> enum page_type btype = PAGE_TYPE_OF_BIO(type);
>>> - struct f2fs_bio_info *io = &sbi->write_io[btype];
>>> - bool ret;
>>> + enum temp_type temp;
>>> + struct f2fs_bio_info *io;
>>> + bool ret = false;
>>>
>>> - down_read(&io->io_rwsem);
>>> - ret = __has_merged_page(io, inode, ino, idx);
>>> - up_read(&io->io_rwsem);
>>> + for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
>>> + io = sbi->write_io[btype] + temp;
>>> +
>>> + down_read(&io->io_rwsem);
>>> + ret = __has_merged_page(io, inode, ino, idx);
>>> + up_read(&io->io_rwsem);
>>> +
>>> + /* TODO: use HOT temp only for meta pages now. */
>>> + if (ret || btype == META)
>>> + break;
>>> + }
>>> return ret;
>>> }
>>>
>>> static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
>>> struct inode *inode, nid_t ino, pgoff_t idx,
>>> - enum page_type type)
>>> + enum page_type type, enum temp_type temp)
>>> {
>>> enum page_type btype = PAGE_TYPE_OF_BIO(type);
>>> - struct f2fs_bio_info *io = &sbi->write_io[btype];
>>> + struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
>>>
>>> down_write(&io->io_rwsem);
>>>
>>> @@ -316,17 +325,34 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
>>> up_write(&io->io_rwsem);
>>> }
>>>
>>> +static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
>>> + struct inode *inode, nid_t ino, pgoff_t idx,
>>> + enum page_type type, bool force)
>>> +{
>>> + enum temp_type temp;
>>> +
>>> + if (!force && !has_merged_page(sbi, inode, ino, idx, type))
>>> + return;
>>> +
>>> + for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
>>> + __f2fs_submit_merged_write(sbi, inode, ino, idx, type, temp);
>>> +
>>> + /* TODO: use HOT temp only for meta pages now. */
>>> + if (type >= META)
>>> + break;
>>> + }
>>> +}
>>> +
>>> void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
>>> {
>>> - __f2fs_submit_merged_write(sbi, NULL, 0, 0, type);
>>> + __submit_merged_write_cond(sbi, NULL, 0, 0, type, true);
>>> }
>>>
>>> void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
>>> struct inode *inode, nid_t ino, pgoff_t idx,
>>> enum page_type type)
>>> {
>>> - if (has_merged_page(sbi, inode, ino, idx, type))
>>> - __f2fs_submit_merged_write(sbi, inode, ino, idx, type);
>>> + __submit_merged_write_cond(sbi, inode, ino, idx, type, false);
>>> }
>>>
>>> void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
>>> @@ -369,7 +395,7 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
>>> {
>>> struct f2fs_sb_info *sbi = fio->sbi;
>>> enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
>>> - struct f2fs_bio_info *io = &sbi->write_io[btype];
>>> + struct f2fs_bio_info *io = sbi->write_io[btype] + fio->temp;
>>> struct page *bio_page;
>>> int err = 0;
>>>
>>> @@ -405,8 +431,7 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
>>> io->fio = *fio;
>>> }
>>>
>>> - if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
>>> - PAGE_SIZE) {
>>> + if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {
>>> __submit_merged_bio(io);
>>> goto alloc_new;
>>> }
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index bf837458cb18..90e97bc11972 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -792,9 +792,17 @@ enum page_type {
>>> OPU,
>>> };
>>>
>>> +enum temp_type {
>>> + HOT = 0, /* must be zero for meta bio */
>>> + WARM,
>>> + COLD,
>>> + NR_TEMP_TYPE,
>>> +};
>>> +
>>> struct f2fs_io_info {
>>> struct f2fs_sb_info *sbi; /* f2fs_sb_info pointer */
>>> enum page_type type; /* contains DATA/NODE/META/META_FLUSH */
>>> + enum temp_type temp; /* contains HOT/WARM/COLD */
>>> int op; /* contains REQ_OP_ */
>>> int op_flags; /* req_flag_bits */
>>> block_t new_blkaddr; /* new block address to be written */
>>> @@ -880,7 +888,7 @@ struct f2fs_sb_info {
>>>
>>> /* for bio operations */
>>> struct f2fs_bio_info read_io; /* for read bios */
>>> - struct f2fs_bio_info write_io[NR_PAGE_TYPE]; /* for write bios */
>>> + struct f2fs_bio_info *write_io[NR_PAGE_TYPE]; /* for write bios */
>>> struct mutex wio_mutex[NODE + 1]; /* bio ordering for NODE/DATA */
>>> int write_io_size_bits; /* Write IO size bits */
>>> mempool_t *write_io_dummy; /* Dummy pages */
>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>>> index 67b87155bc48..e2b13558a915 100644
>>> --- a/fs/f2fs/gc.c
>>> +++ b/fs/f2fs/gc.c
>>> @@ -586,6 +586,7 @@ static void move_encrypted_block(struct inode *inode, block_t bidx,
>>> struct f2fs_io_info fio = {
>>> .sbi = F2FS_I_SB(inode),
>>> .type = DATA,
>>> + .temp = COLD,
>>> .op = REQ_OP_READ,
>>> .op_flags = 0,
>>> .encrypted_page = NULL,
>>> @@ -712,6 +713,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
>>> struct f2fs_io_info fio = {
>>> .sbi = F2FS_I_SB(inode),
>>> .type = DATA,
>>> + .temp = COLD,
>>> .op = REQ_OP_WRITE,
>>> .op_flags = REQ_SYNC,
>>> .old_blkaddr = NULL_ADDR,
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index c9f3a2faee21..da4fd2c29e86 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -2084,17 +2084,29 @@ static int __get_segment_type_6(struct f2fs_io_info *fio)
>>>
>>> static int __get_segment_type(struct f2fs_io_info *fio)
>>> {
>>> + int type;
>>> +
>>> switch (fio->sbi->active_logs) {
>>> case 2:
>>> - return __get_segment_type_2(fio);
>>> + type = __get_segment_type_2(fio);
>>> + break;
>>> case 4:
>>> - return __get_segment_type_4(fio);
>>> + type = __get_segment_type_4(fio);
>>> + break;
>>> + case 6:
>>> + type = __get_segment_type_6(fio);
>>> + break;
>>> + default:
>>> + f2fs_bug_on(fio->sbi, true);
>>> }
>>>
>>> - /* NR_CURSEG_TYPE(6) logs by default */
>>> - f2fs_bug_on(fio->sbi, fio->sbi->active_logs != NR_CURSEG_TYPE);
>>> -
>>> - return __get_segment_type_6(fio);
>>> + if (IS_HOT(type))
>>> + fio->temp = HOT;
>>> + else if (IS_WARM(type))
>>> + fio->temp = WARM;
>>> + else
>>> + fio->temp = COLD;
>>> + return type;
>>> }
>>>
>>> void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
>>> index 10bf05d4cff4..e9ba1f1d9723 100644
>>> --- a/fs/f2fs/segment.h
>>> +++ b/fs/f2fs/segment.h
>>> @@ -27,6 +27,10 @@
>>> #define IS_DATASEG(t) ((t) <= CURSEG_COLD_DATA)
>>> #define IS_NODESEG(t) ((t) >= CURSEG_HOT_NODE)
>>>
>>> +#define IS_HOT(t) ((t) == CURSEG_HOT_NODE || (t) == CURSEG_HOT_DATA)
>>> +#define IS_WARM(t) ((t) == CURSEG_WARM_NODE || (t) == CURSEG_WARM_DATA)
>>> +#define IS_COLD(t) ((t) == CURSEG_COLD_NODE || (t) == CURSEG_COLD_DATA)
>>> +
>>> #define IS_CURSEG(sbi, seg) \
>>> (((seg) == CURSEG_I(sbi, CURSEG_HOT_DATA)->segno) || \
>>> ((seg) == CURSEG_I(sbi, CURSEG_WARM_DATA)->segno) || \
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 104a571a41c0..91599c9c3ef6 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -768,6 +768,7 @@ static void destroy_device_list(struct f2fs_sb_info *sbi)
>>> static void f2fs_put_super(struct super_block *sb)
>>> {
>>> struct f2fs_sb_info *sbi = F2FS_SB(sb);
>>> + int i;
>>>
>>> if (sbi->s_proc) {
>>> remove_proc_entry("segment_info", sbi->s_proc);
>>> @@ -838,6 +839,8 @@ static void f2fs_put_super(struct super_block *sb)
>>> destroy_device_list(sbi);
>>> mempool_destroy(sbi->write_io_dummy);
>>> destroy_percpu_info(sbi);
>>> + for (i = 0; i < NR_PAGE_TYPE; i++)
>>> + kfree(sbi->write_io[i]);
>>> kfree(sbi);
>>> }
>>>
>>> @@ -1954,9 +1957,19 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>>> sbi->read_io.sbi = sbi;
>>> sbi->read_io.bio = NULL;
>>> for (i = 0; i < NR_PAGE_TYPE; i++) {
>>> - init_rwsem(&sbi->write_io[i].io_rwsem);
>>> - sbi->write_io[i].sbi = sbi;
>>> - sbi->write_io[i].bio = NULL;
>>> + int n = (i == META) ? 1: NR_TEMP_TYPE;
>>> + int j;
>>> +
>>> + sbi->write_io[i] = kmalloc(n * sizeof(struct f2fs_bio_info),
>>> + GFP_KERNEL);
>>> + if (!sbi->write_io[i])
>>> + goto free_options;
>>> +
>>> + for (j = HOT; j < n; j++) {
>>> + init_rwsem(&sbi->write_io[i][j].io_rwsem);
>>> + sbi->write_io[i][j].sbi = sbi;
>>> + sbi->write_io[i][j].bio = NULL;
>>> + }
>>> }
>>>
>>> init_rwsem(&sbi->cp_rwsem);
>>> @@ -2202,6 +2215,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>>> free_io_dummy:
>>> mempool_destroy(sbi->write_io_dummy);
>>> free_options:
>>> + for (i = 0; i < NR_PAGE_TYPE; i++)
>>> + kfree(sbi->write_io[i]);
>>> destroy_percpu_info(sbi);
>>> kfree(options);
>>> free_sb_buf:
>>> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
>>> index 5805d92893a8..6f77a2755abb 100644
>>> --- a/include/trace/events/f2fs.h
>>> +++ b/include/trace/events/f2fs.h
>>> @@ -19,6 +19,9 @@ TRACE_DEFINE_ENUM(INMEM_INVALIDATE);
>>> TRACE_DEFINE_ENUM(INMEM_REVOKE);
>>> TRACE_DEFINE_ENUM(IPU);
>>> TRACE_DEFINE_ENUM(OPU);
>>> +TRACE_DEFINE_ENUM(HOT);
>>> +TRACE_DEFINE_ENUM(WARM);
>>> +TRACE_DEFINE_ENUM(COLD);
>>> TRACE_DEFINE_ENUM(CURSEG_HOT_DATA);
>>> TRACE_DEFINE_ENUM(CURSEG_WARM_DATA);
>>> TRACE_DEFINE_ENUM(CURSEG_COLD_DATA);
>>> @@ -59,6 +62,12 @@ TRACE_DEFINE_ENUM(CP_TRIMMED);
>>> { IPU, "IN-PLACE" }, \
>>> { OPU, "OUT-OF-PLACE" })
>>>
>>> +#define show_block_temp(temp) \
>>> + __print_symbolic(temp, \
>>> + { HOT, "HOT" }, \
>>> + { WARM, "WARM" }, \
>>> + { COLD, "COLD" })
>>> +
>>> #define F2FS_OP_FLAGS (REQ_RAHEAD | REQ_SYNC | REQ_META | REQ_PRIO | \
>>> REQ_PREFLUSH | REQ_FUA)
>>> #define F2FS_BIO_FLAG_MASK(t) (t & F2FS_OP_FLAGS)
>>> @@ -757,6 +766,7 @@ DECLARE_EVENT_CLASS(f2fs__submit_page_bio,
>>> __field(block_t, new_blkaddr)
>>> __field(int, op)
>>> __field(int, op_flags)
>>> + __field(int, temp)
>>> __field(int, type)
>>> ),
>>>
>>> @@ -768,16 +778,18 @@ DECLARE_EVENT_CLASS(f2fs__submit_page_bio,
>>> __entry->new_blkaddr = fio->new_blkaddr;
>>> __entry->op = fio->op;
>>> __entry->op_flags = fio->op_flags;
>>> + __entry->temp = fio->temp;
>>> __entry->type = fio->type;
>>> ),
>>>
>>> TP_printk("dev = (%d,%d), ino = %lu, page_index = 0x%lx, "
>>> - "oldaddr = 0x%llx, newaddr = 0x%llx, rw = %s(%s), type = %s",
>>> + "oldaddr = 0x%llx, newaddr = 0x%llx, rw = %s(%s), type = %s_%s",
>>> show_dev_ino(__entry),
>>> (unsigned long)__entry->index,
>>> (unsigned long long)__entry->old_blkaddr,
>>> (unsigned long long)__entry->new_blkaddr,
>>> show_bio_type(__entry->op, __entry->op_flags),
>>> + show_block_temp(__entry->temp),
>>> show_block_type(__entry->type))
>>> );
>>>
>>>
>
> .
>