Re: [f2fs-dev] [PATCH] f2fs: split bio cache

From: Jaegeuk Kim
Date: Fri May 12 2017 - 13:43:56 EST


On 05/12, Chao Yu wrote:
> 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.

I just pushed them into dev-test branch, and have been conducting stress tests.

Thanks,

>
> 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))
> >>> );
> >>>
> >>>
> >
> > .
> >
>
>
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