Convert to lockless lists - intermix with regular list due to that next pointer in both list_head and llist_head is the first field, and prev is not used. Do this so we can make babysteps forward.
https://virtuozzo.atlassian.net/browse/VSTOR-91820 Signed-off-by: Alexander Atanasov <alexander.atana...@virtuozzo.com> --- drivers/md/dm-ploop-bat.c | 3 +-- drivers/md/dm-ploop-map.c | 50 +++++++++++++++++++----------------- drivers/md/dm-ploop-target.c | 2 +- drivers/md/dm-ploop.h | 6 ++--- 4 files changed, 32 insertions(+), 29 deletions(-) diff --git a/drivers/md/dm-ploop-bat.c b/drivers/md/dm-ploop-bat.c index 886a05cdd23a..655d0e4c91ab 100644 --- a/drivers/md/dm-ploop-bat.c +++ b/drivers/md/dm-ploop-bat.c @@ -80,8 +80,7 @@ static struct md_page *ploop_alloc_md_page(u32 id) page = alloc_page(GFP_KERNEL); if (!page) goto err_page; - INIT_LIST_HEAD(&md->wait_list); - INIT_LIST_HEAD(&md->wb_link); + init_llist_head(&md->wait_llist); md->status = 0; md->bat_levels = levels; diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c index fc07d24c34a0..5fb98740f32e 100644 --- a/drivers/md/dm-ploop-map.c +++ b/drivers/md/dm-ploop-map.c @@ -381,13 +381,14 @@ static bool ploop_delay_if_md_busy(struct ploop *ploop, struct md_page *md, WARN_ON_ONCE(!list_empty(&pio->list)); - write_lock_irqsave(&ploop->bat_rwlock, flags); + /* lock protects piwb */ + read_lock_irqsave(&ploop->bat_rwlock, flags); piwb = md->piwb; if (piwb && (piwb->type != type || test_bit(MD_WRITEBACK, &md->status))) { - list_add_tail(&pio->list, &md->wait_list); + llist_add((struct llist_node *)(&pio->list), &md->wait_llist); busy = true; } - write_unlock_irqrestore(&ploop->bat_rwlock, flags); + read_unlock_irqrestore(&ploop->bat_rwlock, flags); return busy; } @@ -546,16 +547,13 @@ static void ploop_unlink_completed_pio(struct ploop *ploop, struct pio *pio) static bool ploop_md_make_dirty(struct ploop *ploop, struct md_page *md) { - unsigned long flags; bool new = false; - write_lock_irqsave(&ploop->bat_rwlock, flags); WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status)); if (!test_and_set_bit(MD_DIRTY, &md->status)) { - list_add_tail(&md->wb_link, &ploop->wb_batch_list); + llist_add(&md->wb_llink, &ploop->wb_batch_llist); new = true; } - write_unlock_irqrestore(&ploop->bat_rwlock, flags); return new; } @@ -757,7 +755,9 @@ static void ploop_advance_local_after_bat_wb(struct ploop *ploop, map_index_t *dst_clu, off; unsigned long flags; LIST_HEAD(list); - + struct llist_node *wait_llist_pending; + struct pio *pio; + struct llist_node *pos, *t; BUG_ON(!md); bat_entries = md->kmpage; @@ -774,8 +774,6 @@ static void ploop_advance_local_after_bat_wb(struct ploop *ploop, i = PLOOP_MAP_OFFSET; dst_clu = kmap_local_page(piwb->bat_page); - write_lock_irqsave(&ploop->bat_rwlock, flags); - for (; i < last; i++) { if (piwb->type == PIWB_TYPE_DISCARD) { ploop_piwb_discard_completed(ploop, success, i + off, dst_clu[i]); @@ -801,11 +799,21 @@ static void ploop_advance_local_after_bat_wb(struct ploop *ploop, WARN_ON_ONCE(!test_bit(MD_WRITEBACK, &md->status)); clear_bit(MD_WRITEBACK, &md->status); + /* protect piwb */ + write_lock_irqsave(&ploop->bat_rwlock, flags); md->piwb = NULL; - list_splice_tail_init(&md->wait_list, &list); write_unlock_irqrestore(&ploop->bat_rwlock, flags); kunmap_local(dst_clu); + wait_llist_pending = llist_del_all(&md->wait_llist); + if (wait_llist_pending) { + wait_llist_pending = llist_reverse_order(wait_llist_pending); + llist_for_each_safe(pos, t, wait_llist_pending) { + pio = list_entry((struct list_head *)pos, typeof(*pio), list); + list_add(&pio->list, &list); + } + } + if (!list_empty(&list)) ploop_dispatch_pios(ploop, NULL, &list); } @@ -1764,22 +1772,18 @@ static void ploop_process_resubmit_pios(struct ploop *ploop, static void ploop_submit_metadata_writeback(struct ploop *ploop) { struct md_page *md; - while (1) { - write_lock_irq(&ploop->bat_rwlock); - md = list_first_entry_or_null(&ploop->wb_batch_list, - struct md_page, wb_link); - if (!md) { - write_unlock_irq(&ploop->bat_rwlock); - break; - } - list_del_init(&md->wb_link); - /* L1L2 mustn't be redirtyed, when wb in-flight! */ + struct md_page *t; + struct llist_node *wbl; + + wbl = llist_del_all(&ploop->wb_batch_llist); + if (!wbl) + return; + wbl = llist_reverse_order(wbl); + llist_for_each_entry_safe(md, t, wbl, wb_llink) { WARN_ON_ONCE(!test_bit(MD_DIRTY, &md->status)); WARN_ON_ONCE(test_bit(MD_WRITEBACK, &md->status)); set_bit(MD_WRITEBACK, &md->status); clear_bit(MD_DIRTY, &md->status); - write_unlock_irq(&ploop->bat_rwlock); - ploop_index_wb_submit(ploop, md->piwb); } } diff --git a/drivers/md/dm-ploop-target.c b/drivers/md/dm-ploop-target.c index 8b3b840dea66..b66ae3a9a4b0 100644 --- a/drivers/md/dm-ploop-target.c +++ b/drivers/md/dm-ploop-target.c @@ -378,7 +378,7 @@ static int ploop_ctr(struct dm_target *ti, unsigned int argc, char **argv) INIT_LIST_HEAD(&ploop->resubmit_pios); INIT_LIST_HEAD(&ploop->enospc_pios); INIT_LIST_HEAD(&ploop->cluster_lk_list); - INIT_LIST_HEAD(&ploop->wb_batch_list); + init_llist_head(&ploop->wb_batch_llist); ploop->bat_entries = RB_ROOT; timer_setup(&ploop->enospc_timer, ploop_enospc_timer, 0); diff --git a/drivers/md/dm-ploop.h b/drivers/md/dm-ploop.h index 75329adafb56..b640bf275473 100644 --- a/drivers/md/dm-ploop.h +++ b/drivers/md/dm-ploop.h @@ -120,9 +120,9 @@ struct md_page { struct page *page; void *kmpage; u8 *bat_levels; - struct list_head wait_list; + struct llist_head wait_llist; - struct list_head wb_link; + struct llist_node wb_llink; struct ploop_index_wb *piwb; }; @@ -165,7 +165,7 @@ struct ploop { u32 hb_nr; /* holes_bitmap size in bits */ rwlock_t bat_rwlock; - struct list_head wb_batch_list; + struct llist_head wb_batch_llist; /* * Hash table to link non-exclusive submitted bios. -- 2.43.0 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
