On 01/04/2016 10:54 AM, Wenwei Tao wrote:
We allocate gcb to queue full block to the gc list,
but gcb allocation may fail, if that happens, the
block will not get reclaimed. So add the full block
direct to the gc list, omit the queuing step.
Signed-off-by: Wenwei Tao <ww.tao0320@xxxxxxxxx>
---
drivers/lightnvm/rrpc.c | 47 ++++++++++-------------------------------------
1 file changed, 10 insertions(+), 37 deletions(-)
diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index 40b0309..27fb98d 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -475,24 +475,6 @@ static void rrpc_lun_gc(struct work_struct *work)
/* TODO: Hint that request queue can be started again */
}
-static void rrpc_gc_queue(struct work_struct *work)
-{
- struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
- ws_gc);
- struct rrpc *rrpc = gcb->rrpc;
- struct rrpc_block *rblk = gcb->rblk;
- struct nvm_lun *lun = rblk->parent->lun;
- struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
-
- spin_lock(&rlun->lock);
- list_add_tail(&rblk->prio, &rlun->prio_list);
- spin_unlock(&rlun->lock);
-
- mempool_free(gcb, rrpc->gcb_pool);
- pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
- rblk->parent->id);
-}
-
static const struct block_device_operations rrpc_fops = {
.owner = THIS_MODULE,
};
@@ -620,39 +602,30 @@ err:
return NULL;
}
-static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
-{
- struct rrpc_block_gc *gcb;
-
- gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
- if (!gcb) {
- pr_err("rrpc: unable to queue block for gc.");
- return;
- }
-
- gcb->rrpc = rrpc;
- gcb->rblk = rblk;
-
- INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
- queue_work(rrpc->kgc_wq, &gcb->ws_gc);
-}
-
static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
sector_t laddr, uint8_t npages)
{
struct rrpc_addr *p;
struct rrpc_block *rblk;
struct nvm_lun *lun;
+ struct rrpc_lun *rlun;
int cmnt_size, i;
for (i = 0; i < npages; i++) {
p = &rrpc->trans_map[laddr + i];
rblk = p->rblk;
lun = rblk->parent->lun;
+ rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
- if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
- rrpc_run_gc(rrpc, rblk);
+ if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk)) {
+ pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
+ rblk->parent->id);
+ spin_lock(&rlun->lock);
A deadlock might occur, as the lock can be called from interrupt
context. The other ->rlun usages will have to be converted to
spinlock_irqsave/spinlock_irqrestore to be valid.
The reason for the queueing is that the ->rlun lock is held for a while
in rrpc_lun_gc. Therefore, it rather takes the queueing overhead, than
disable interrupts on the CPU for the duration of the ->prio sorting and
selection of victim block. My assumptions about this optimization might
be premature. So I like to be proved wrong.
+ list_add_tail(&rblk->prio, &rlun->prio_list);
+ spin_unlock(&rlun->lock);
+
+ }
}
}
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