search for: percpu_ida_alloc

...k_irqrestore(qpair->qp_lock_ptr, flags); spin_lock_irqsave(&ha->tgt.sess_lock, flags); @@ -4215,9 +4217,9 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha, { struct se_session *se_sess = sess->se_sess; struct qla_tgt_cmd *cmd; - int tag; + int tag, cpu; - tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); if (tag < 0) return NULL; @@ -4230,6 +4232,7 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha, qlt_incr_num_pend_cmds(vha); cmd->vha = vha; cmd->se...

From: Matthew Wilcox <mawilcox at microsoft.com> This is a pretty rough-and-ready conversion of the target drivers from using percpu_ida to sbitmap. It compiles; I don't have a target setup, so it's completely untested. I haven't tried to do anything particularly clever here, so it's possible that, for example, the wait queue in iscsi_target_util could be more clever, like

Removing the percpu_ida code nets over 400 lines of removal. It's not as spectacular as deleting an entire architecture, but it's still a worthy reduction in lines of code. Untested due to lack of hardware and not understanding how to set up a target platform. Changes from v1: - Fixed bugs pointed out by Jens in iscsit_wait_for_tag() - Abstracted out tag freeing as requested by Bart

Removing the percpu_ida code nets over 400 lines of removal. It's not as spectacular as deleting an entire architecture, but it's still a worthy reduction in lines of code. Untested due to lack of hardware and not understanding how to set up a target platform. Changes from v1: - Fixed bugs pointed out by Jens in iscsit_wait_for_tag() - Abstracted out tag freeing as requested by Bart

From: Nicholas Bellinger <nab at linux-iscsi.org> Hi folks, This is an updated series for adding tag pre-allocation support of target fabric descriptor memory, utilizing Kent's latest per-cpu ida bits here, along with Christoph Lameter's latest comments: [PATCH 04/10] idr: Percpu ida http://marc.info/?l=linux-kernel&m=137160026006974&w=2 The first patch is a

From: Nicholas Bellinger <nab at linux-iscsi.org> Hi folks, This is an updated series for adding tag pre-allocation support of target fabric descriptor memory, utilizing Kent's latest per-cpu ida bits here, along with Christoph Lameter's latest comments: [PATCH 04/10] idr: Percpu ida http://marc.info/?l=linux-kernel&m=137160026006974&w=2 The first patch is a

...ent: + */ + unsigned cpu_last_stolen; + + /* For sleeping on allocation failure */ + wait_queue_head_t wait; + + /* + * Global freelist - it's a stack where nr_free points to the + * top + */ + unsigned nr_free; + unsigned *freelist; + } ____cacheline_aligned_in_smp; +}; + +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp); +void percpu_ida_free(struct percpu_ida *pool, unsigned tag); + +void percpu_ida_destroy(struct percpu_ida *pool); +int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags); + #endif /* __IDR_H__ */ diff --git a/lib/idr.c b/lib/idr.c index bfe4db4..5...

...+ spin_lock(&tags->lock); > + if (tags->nr_free) > + tag = tags->freelist[--tags->nr_free]; > + spin_unlock(&tags->lock); > + > + return tag; > +} I guess this one's clear enough, if the data structure relationships are understood. > +/** > + * percpu_ida_alloc - allocate a tag > + * @pool: pool to allocate from > + * @gfp: gfp flags > + * > + * Returns a tag - an integer in the range [0..nr_tags) (passed to > + * tag_pool_init()), or otherwise -ENOSPC on allocation failure. > + * > + * Safe to be called from interrupt context (assumi...

...+ spin_lock(&tags->lock); > + if (tags->nr_free) > + tag = tags->freelist[--tags->nr_free]; > + spin_unlock(&tags->lock); > + > + return tag; > +} I guess this one's clear enough, if the data structure relationships are understood. > +/** > + * percpu_ida_alloc - allocate a tag > + * @pool: pool to allocate from > + * @gfp: gfp flags > + * > + * Returns a tag - an integer in the range [0..nr_tags) (passed to > + * tag_pool_init()), or otherwise -ENOSPC on allocation failure. > + * > + * Safe to be called from interrupt context (assumi...

...he range [0..nr_tags) (passed to > + * tag_pool_init()), or otherwise -ENOSPC on allocation failure. > + * > + * Safe to be called from interrupt context (assuming it isn't passed > + * __GFP_WAIT, of course). > + * > + * Will not fail if passed __GFP_WAIT. > + */ > +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) > +{ > + DEFINE_WAIT(wait); > + struct percpu_ida_cpu *tags; > + unsigned long flags; > + int tag; > + > + local_irq_save(flags); > + tags = this_cpu_ptr(pool->tag_cpu); You could drop this_cpu_ptr if you pass pool->tag_cpu to alloc...

...he range [0..nr_tags) (passed to > + * tag_pool_init()), or otherwise -ENOSPC on allocation failure. > + * > + * Safe to be called from interrupt context (assuming it isn't passed > + * __GFP_WAIT, of course). > + * > + * Will not fail if passed __GFP_WAIT. > + */ > +int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) > +{ > + DEFINE_WAIT(wait); > + struct percpu_ida_cpu *tags; > + unsigned long flags; > + int tag; > + > + local_irq_save(flags); > + tags = this_cpu_ptr(pool->tag_cpu); You could drop this_cpu_ptr if you pass pool->tag_cpu to alloc...

...passed __GFP_WAIT we terminate iff we succesfully allocated a tag. If we weren't passed __GFP_WAIT we never actually sleep. I can add a comment if you think it needs one. > > + finish_wait(&pool->wait, &wait); > > + return tag; > > +} > > +EXPORT_SYMBOL_GPL(percpu_ida_alloc); > > + > > +/** > > + * percpu_ida_free - free a tag > > + * @pool: pool @tag was allocated from > > + * @tag: a tag previously allocated with percpu_ida_alloc() > > + * > > + * Safe to be called from interrupt context. > > + */ > > +void percp...

...cating > * iSCSI NopINs. > @@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state) > { > struct iscsi_cmd *cmd; > struct se_session *se_sess = conn->sess->se_sess; > - int size, tag; > + int size, tag, cpu; > > - tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state); > + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); > + if (tag < 0) > + tag = iscsit_wait_for_tag(se_sess, state, &cpu); > if (tag < 0) > return NULL; Might make sense to just roll the whole thing into iscsi...

...cating > * iSCSI NopINs. > @@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state) > { > struct iscsi_cmd *cmd; > struct se_session *se_sess = conn->sess->se_sess; > - int size, tag; > + int size, tag, cpu; > > - tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state); > + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); > + if (tag < 0) > + tag = iscsit_wait_for_tag(se_sess, state, &cpu); > if (tag < 0) > return NULL; Might make sense to just roll the whole thing into iscsi...

...t;> @@ -155,9 +177,11 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state) >> { >> struct iscsi_cmd *cmd; >> struct se_session *se_sess = conn->sess->se_sess; >> - int size, tag; >> + int size, tag, cpu; >> >> - tag = percpu_ida_alloc(&se_sess->sess_tag_pool, state); >> + tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); >> + if (tag < 0) >> + tag = iscsit_wait_for_tag(se_sess, state, &cpu); >> if (tag < 0) >> return NULL; > > Might make sense to just r...

...tes whether or not to wait until a free id is available (it's not + * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep + * however long it takes until another thread frees an id (same semantics as a + * mempool). + * * Will not fail if passed __GFP_WAIT. */ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)

...ne void steal_tags(struct percpu_ida *pool, } } +/* + * Pop up to IDA_PCPU_BATCH_MOVE IDs off the global freelist, and push them onto + * our percpu freelist: + */ static inline void alloc_global_tags(struct percpu_ida *pool, struct percpu_ida_cpu *tags) { @@ -1317,8 +1327,8 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) if (tags->nr_free) { tag = tags->freelist[--tags->nr_free]; if (tags->nr_free) - set_bit(smp_processor_id(), - pool->cpus_have_tags); + cpumask_set_cpu(smp_processor_id(), + &pool->cpus_have_tags); } spin_un...

From: Nicholas Bellinger <nab at linux-iscsi.org> Hi folks, This is an updated series for adding tag pre-allocation support of target fabric descriptor memory, utilizing Kent's latest in-flight per-cpu ida bits here: [PATCH v3] lib/idr.c rewrite, percpu ida/tag allocator http://marc.info/?l=linux-kernel&m=137308733526328&w=2 Patch #1 includes target-core setup of

From: Nicholas Bellinger <nab at linux-iscsi.org> Hi folks, This is an updated series for adding tag pre-allocation support of target fabric descriptor memory, utilizing Kent's latest in-flight per-cpu ida bits here: [PATCH v3] lib/idr.c rewrite, percpu ida/tag allocator http://marc.info/?l=linux-kernel&m=137308733526328&w=2 Patch #1 includes target-core setup of

On Wed, 28 Aug 2013 13:44:54 -0700 Kent Overstreet <kmo at daterainc.com> wrote: > > > > What guarantees that this wait will terminate? > > > > > > It seems fairly clear to me from the break statement a couple lines up; > > > if we were passed __GFP_WAIT we terminate iff we succesfully allocated a > > > tag. If we weren't passed