[PATCH 0/6] padata cleanups

[PATCH 0/6] padata cleanups

[Daniel Jordan]

These cleanups save ~5% of the padata text/data and make it a little
easier to use and develop going forward.

In particular, they pave the way to extend padata's multithreading support to
VFIO, a work-in-progress version of which can be found here:

    https://oss.oracle.com/git/gitweb.cgi?p=linux-dmjordan.git;a=shortlog;h=refs/heads/padata-mt-wip-v0.5

Based on v5.8-rc5.  As always, feedback is welcome.

Daniel

Daniel Jordan (6):
  padata: remove start function
  padata: remove stop function
  padata: inline single call of pd_setup_cpumasks()
  padata: remove effective cpumasks from the instance
  padata: fold padata_alloc_possible() into padata_alloc()
  padata: remove padata_parallel_queue

 Documentation/core-api/padata.rst |  18 +--
 crypto/pcrypt.c                   |  17 +--
 include/linux/padata.h            |  21 +---
 kernel/padata.c                   | 177 ++++++------------------------
 4 files changed, 46 insertions(+), 187 deletions(-)


base-commit: 11ba468877bb23f28956a35e896356252d63c983
-- 
2.27.0

[PATCH 1/6] padata: remove start function

[Daniel Jordan]

padata_start() is only used right after pcrypt allocates an instance
with all possible CPUs, when PADATA_INVALID can't happen, so there's no
need for a separate "start" step.  It can be done during allocation to
save text, make using padata easier, and avoid unneeded calls in the
future.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 crypto/pcrypt.c        |  3 ---
 include/linux/padata.h |  1 -
 kernel/padata.c        | 26 +-------------------------
 3 files changed, 1 insertion(+), 29 deletions(-)

diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 8bddc65cd5092..4f5707a3dd1e9 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -359,9 +359,6 @@ static int __init pcrypt_init(void)
 	if (err)
 		goto err_deinit_pencrypt;
 
-	padata_start(pencrypt);
-	padata_start(pdecrypt);
-
 	return crypto_register_template(&pcrypt_tmpl);
 
 err_deinit_pencrypt:
diff --git a/include/linux/padata.h b/include/linux/padata.h
index 7302efff5e656..20294cddc7396 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -204,6 +204,5 @@ extern void padata_do_serial(struct padata_priv *padata);
 extern void __init padata_do_multithreaded(struct padata_mt_job *job);
 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 			      cpumask_var_t cpumask);
-extern int padata_start(struct padata_instance *pinst);
 extern void padata_stop(struct padata_instance *pinst);
 #endif
diff --git a/kernel/padata.c b/kernel/padata.c
index 4373f7adaa40a..9317623166124 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -789,30 +789,6 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 }
 EXPORT_SYMBOL(padata_set_cpumask);
 
-/**
- * padata_start - start the parallel processing
- *
- * @pinst: padata instance to start
- *
- * Return: 0 on success or negative error code
- */
-int padata_start(struct padata_instance *pinst)
-{
-	int err = 0;
-
-	mutex_lock(&pinst->lock);
-
-	if (pinst->flags & PADATA_INVALID)
-		err = -EINVAL;
-
-	__padata_start(pinst);
-
-	mutex_unlock(&pinst->lock);
-
-	return err;
-}
-EXPORT_SYMBOL(padata_start);
-
 /**
  * padata_stop - stop the parallel processing
  *
@@ -1100,7 +1076,7 @@ static struct padata_instance *padata_alloc(const char *name,
 	if (padata_setup_cpumasks(pinst))
 		goto err_free_rcpumask_cbcpu;
 
-	pinst->flags = 0;
+	__padata_start(pinst);
 
 	kobject_init(&pinst->kobj, &padata_attr_type);
 	mutex_init(&pinst->lock);
-- 
2.27.0

[PATCH 2/6] padata: remove stop function

[Daniel Jordan]

padata_stop() has two callers and is unnecessary in both cases.  When
pcrypt calls it before padata_free(), it's being unloaded so there are
no outstanding padata jobs[0].  When __padata_free() calls it, it's
either along the same path or else pcrypt initialization failed, which
of course means there are also no outstanding jobs.

Removing it simplifies padata and saves text.

[0] https://lore.kernel.org/linux-crypto/20191119225017.mjrak2fwa5vccazl@gondor.apana.org.au/

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 Documentation/core-api/padata.rst | 16 ++--------------
 crypto/pcrypt.c                   | 12 +++---------
 include/linux/padata.h            |  1 -
 kernel/padata.c                   | 14 --------------
 4 files changed, 5 insertions(+), 38 deletions(-)

diff --git a/Documentation/core-api/padata.rst b/Documentation/core-api/padata.rst
index 0830e5b0e8211..771d50330e5b5 100644
--- a/Documentation/core-api/padata.rst
+++ b/Documentation/core-api/padata.rst
@@ -31,18 +31,7 @@ padata_instance structure for overall control of how jobs are to be run::
 
 'name' simply identifies the instance.
 
-There are functions for enabling and disabling the instance::
-
-    int padata_start(struct padata_instance *pinst);
-    void padata_stop(struct padata_instance *pinst);
-
-These functions are setting or clearing the "PADATA_INIT" flag; if that flag is
-not set, other functions will refuse to work.  padata_start() returns zero on
-success (flag set) or -EINVAL if the padata cpumask contains no active CPU
-(flag not set).  padata_stop() clears the flag and blocks until the padata
-instance is unused.
-
-Finally, complete padata initialization by allocating a padata_shell::
+Then, complete padata initialization by allocating a padata_shell::
 
    struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);
 
@@ -155,11 +144,10 @@ submitted.
 Destroying
 ----------
 
-Cleaning up a padata instance predictably involves calling the three free
+Cleaning up a padata instance predictably involves calling the two free
 functions that correspond to the allocation in reverse::
 
     void padata_free_shell(struct padata_shell *ps);
-    void padata_stop(struct padata_instance *pinst);
     void padata_free(struct padata_instance *pinst);
 
 It is the user's responsibility to ensure all outstanding jobs are complete
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 4f5707a3dd1e9..7374dfecaf70f 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -331,12 +331,6 @@ static int pcrypt_init_padata(struct padata_instance **pinst, const char *name)
 	return ret;
 }
 
-static void pcrypt_fini_padata(struct padata_instance *pinst)
-{
-	padata_stop(pinst);
-	padata_free(pinst);
-}
-
 static struct crypto_template pcrypt_tmpl = {
 	.name = "pcrypt",
 	.create = pcrypt_create,
@@ -362,7 +356,7 @@ static int __init pcrypt_init(void)
 	return crypto_register_template(&pcrypt_tmpl);
 
 err_deinit_pencrypt:
-	pcrypt_fini_padata(pencrypt);
+	padata_free(pencrypt);
 err_unreg_kset:
 	kset_unregister(pcrypt_kset);
 err:
@@ -373,8 +367,8 @@ static void __exit pcrypt_exit(void)
 {
 	crypto_unregister_template(&pcrypt_tmpl);
 
-	pcrypt_fini_padata(pencrypt);
-	pcrypt_fini_padata(pdecrypt);
+	padata_free(pencrypt);
+	padata_free(pdecrypt);
 
 	kset_unregister(pcrypt_kset);
 }
diff --git a/include/linux/padata.h b/include/linux/padata.h
index 20294cddc7396..7d53208b43daa 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -204,5 +204,4 @@ extern void padata_do_serial(struct padata_priv *padata);
 extern void __init padata_do_multithreaded(struct padata_mt_job *job);
 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 			      cpumask_var_t cpumask);
-extern void padata_stop(struct padata_instance *pinst);
 #endif
diff --git a/kernel/padata.c b/kernel/padata.c
index 9317623166124..8f55e717ba50b 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -789,19 +789,6 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 }
 EXPORT_SYMBOL(padata_set_cpumask);
 
-/**
- * padata_stop - stop the parallel processing
- *
- * @pinst: padata instance to stop
- */
-void padata_stop(struct padata_instance *pinst)
-{
-	mutex_lock(&pinst->lock);
-	__padata_stop(pinst);
-	mutex_unlock(&pinst->lock);
-}
-EXPORT_SYMBOL(padata_stop);
-
 #ifdef CONFIG_HOTPLUG_CPU
 
 static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
@@ -883,7 +870,6 @@ static void __padata_free(struct padata_instance *pinst)
 
 	WARN_ON(!list_empty(&pinst->pslist));
 
-	padata_stop(pinst);
 	free_cpumask_var(pinst->rcpumask.cbcpu);
 	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
-- 
2.27.0

[PATCH 3/6] padata: inline single call of pd_setup_cpumasks()

[Daniel Jordan]

pd_setup_cpumasks() has only one caller.  Move its contents inline to
prepare for the next cleanup.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 kernel/padata.c | 32 +++++++++-----------------------
 1 file changed, 9 insertions(+), 23 deletions(-)

diff --git a/kernel/padata.c b/kernel/padata.c
index 8f55e717ba50b..27f90a3c4dc6b 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -441,28 +441,6 @@ static int padata_setup_cpumasks(struct padata_instance *pinst)
 	return err;
 }
 
-static int pd_setup_cpumasks(struct parallel_data *pd,
-			     const struct cpumask *pcpumask,
-			     const struct cpumask *cbcpumask)
-{
-	int err = -ENOMEM;
-
-	if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
-		goto out;
-	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
-		goto free_pcpu_mask;
-
-	cpumask_copy(pd->cpumask.pcpu, pcpumask);
-	cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
-
-	return 0;
-
-free_pcpu_mask:
-	free_cpumask_var(pd->cpumask.pcpu);
-out:
-	return err;
-}
-
 static void __init padata_mt_helper(struct work_struct *w)
 {
 	struct padata_work *pw = container_of(w, struct padata_work, pw_work);
@@ -613,8 +591,14 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 		goto err_free_pqueue;
 
 	pd->ps = ps;
-	if (pd_setup_cpumasks(pd, pcpumask, cbcpumask))
+
+	if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
 		goto err_free_squeue;
+	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
+		goto err_free_pcpu;
+
+	cpumask_copy(pd->cpumask.pcpu, pcpumask);
+	cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
 
 	padata_init_pqueues(pd);
 	padata_init_squeues(pd);
@@ -626,6 +610,8 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 
 	return pd;
 
+err_free_pcpu:
+	free_cpumask_var(pd->cpumask.pcpu);
 err_free_squeue:
 	free_percpu(pd->squeue);
 err_free_pqueue:
-- 
2.27.0

[PATCH 4/6] padata: remove effective cpumasks from the instance

[Daniel Jordan]

A padata instance has effective cpumasks that store the user-supplied
masks ANDed with the online mask, but this middleman is unnecessary.
parallel_data keeps the same information around.  Removing this saves
text and code churn in future changes.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 include/linux/padata.h |  2 --
 kernel/padata.c        | 30 +++---------------------------
 2 files changed, 3 insertions(+), 29 deletions(-)

diff --git a/include/linux/padata.h b/include/linux/padata.h
index 7d53208b43daa..a941b96b7119e 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -167,7 +167,6 @@ struct padata_mt_job {
  * @serial_wq: The workqueue used for serial work.
  * @pslist: List of padata_shell objects attached to this instance.
  * @cpumask: User supplied cpumasks for parallel and serial works.
- * @rcpumask: Actual cpumasks based on user cpumask and cpu_online_mask.
  * @kobj: padata instance kernel object.
  * @lock: padata instance lock.
  * @flags: padata flags.
@@ -179,7 +178,6 @@ struct padata_instance {
 	struct workqueue_struct		*serial_wq;
 	struct list_head		pslist;
 	struct padata_cpumask		cpumask;
-	struct padata_cpumask		rcpumask;
 	struct kobject                   kobj;
 	struct mutex			 lock;
 	u8				 flags;
diff --git a/kernel/padata.c b/kernel/padata.c
index 27f90a3c4dc6b..4f0a57e5738c9 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -571,13 +571,8 @@ static void padata_init_pqueues(struct parallel_data *pd)
 static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 {
 	struct padata_instance *pinst = ps->pinst;
-	const struct cpumask *cbcpumask;
-	const struct cpumask *pcpumask;
 	struct parallel_data *pd;
 
-	cbcpumask = pinst->rcpumask.cbcpu;
-	pcpumask = pinst->rcpumask.pcpu;
-
 	pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
 	if (!pd)
 		goto err;
@@ -597,8 +592,8 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 	if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL))
 		goto err_free_pcpu;
 
-	cpumask_copy(pd->cpumask.pcpu, pcpumask);
-	cpumask_copy(pd->cpumask.cbcpu, cbcpumask);
+	cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask);
+	cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask);
 
 	padata_init_pqueues(pd);
 	padata_init_squeues(pd);
@@ -668,12 +663,6 @@ static int padata_replace(struct padata_instance *pinst)
 
 	pinst->flags |= PADATA_RESET;
 
-	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
-		    cpu_online_mask);
-
-	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
-		    cpu_online_mask);
-
 	list_for_each_entry(ps, &pinst->pslist, list) {
 		err = padata_replace_one(ps);
 		if (err)
@@ -856,8 +845,6 @@ static void __padata_free(struct padata_instance *pinst)
 
 	WARN_ON(!list_empty(&pinst->pslist));
 
-	free_cpumask_var(pinst->rcpumask.cbcpu);
-	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
 	destroy_workqueue(pinst->serial_wq);
@@ -1033,20 +1020,13 @@ static struct padata_instance *padata_alloc(const char *name,
 	    !padata_validate_cpumask(pinst, cbcpumask))
 		goto err_free_masks;
 
-	if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL))
-		goto err_free_masks;
-	if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL))
-		goto err_free_rcpumask_pcpu;
-
 	INIT_LIST_HEAD(&pinst->pslist);
 
 	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
 	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
-	cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask);
-	cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
 
 	if (padata_setup_cpumasks(pinst))
-		goto err_free_rcpumask_cbcpu;
+		goto err_free_masks;
 
 	__padata_start(pinst);
 
@@ -1064,10 +1044,6 @@ static struct padata_instance *padata_alloc(const char *name,
 
 	return pinst;
 
-err_free_rcpumask_cbcpu:
-	free_cpumask_var(pinst->rcpumask.cbcpu);
-err_free_rcpumask_pcpu:
-	free_cpumask_var(pinst->rcpumask.pcpu);
 err_free_masks:
 	free_cpumask_var(pinst->cpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.cbcpu);
-- 
2.27.0

[PATCH 5/6] padata: fold padata_alloc_possible() into padata_alloc()

[Daniel Jordan]

There's no reason to have two interfaces when there's only one caller.
Removing _possible saves text and simplifies future changes.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 Documentation/core-api/padata.rst |  2 +-
 crypto/pcrypt.c                   |  2 +-
 include/linux/padata.h            |  2 +-
 kernel/padata.c                   | 33 +++++--------------------------
 4 files changed, 8 insertions(+), 31 deletions(-)

diff --git a/Documentation/core-api/padata.rst b/Documentation/core-api/padata.rst
index 771d50330e5b5..35175710b43cc 100644
--- a/Documentation/core-api/padata.rst
+++ b/Documentation/core-api/padata.rst
@@ -27,7 +27,7 @@ padata_instance structure for overall control of how jobs are to be run::
 
     #include <linux/padata.h>
 
-    struct padata_instance *padata_alloc_possible(const char *name);
+    struct padata_instance *padata_alloc(const char *name);
 
 'name' simply identifies the instance.
 
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 7374dfecaf70f..812892732a5e5 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -320,7 +320,7 @@ static int pcrypt_init_padata(struct padata_instance **pinst, const char *name)
 {
 	int ret = -ENOMEM;
 
-	*pinst = padata_alloc_possible(name);
+	*pinst = padata_alloc(name);
 	if (!*pinst)
 		return ret;
 
diff --git a/include/linux/padata.h b/include/linux/padata.h
index a941b96b7119e..070a7d43e8af8 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -192,7 +192,7 @@ extern void __init padata_init(void);
 static inline void __init padata_init(void) {}
 #endif
 
-extern struct padata_instance *padata_alloc_possible(const char *name);
+extern struct padata_instance *padata_alloc(const char *name);
 extern void padata_free(struct padata_instance *pinst);
 extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);
 extern void padata_free_shell(struct padata_shell *ps);
diff --git a/kernel/padata.c b/kernel/padata.c
index 4f0a57e5738c9..1c0b97891edb8 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -979,18 +979,12 @@ static struct kobj_type padata_attr_type = {
 };
 
 /**
- * padata_alloc - allocate and initialize a padata instance and specify
- *                cpumasks for serial and parallel workers.
- *
+ * padata_alloc - allocate and initialize a padata instance
  * @name: used to identify the instance
- * @pcpumask: cpumask that will be used for padata parallelization
- * @cbcpumask: cpumask that will be used for padata serialization
  *
  * Return: new instance on success, NULL on error
  */
-static struct padata_instance *padata_alloc(const char *name,
-					    const struct cpumask *pcpumask,
-					    const struct cpumask *cbcpumask)
+struct padata_instance *padata_alloc(const char *name)
 {
 	struct padata_instance *pinst;
 
@@ -1016,14 +1010,11 @@ static struct padata_instance *padata_alloc(const char *name,
 		free_cpumask_var(pinst->cpumask.pcpu);
 		goto err_free_serial_wq;
 	}
-	if (!padata_validate_cpumask(pinst, pcpumask) ||
-	    !padata_validate_cpumask(pinst, cbcpumask))
-		goto err_free_masks;
 
 	INIT_LIST_HEAD(&pinst->pslist);
 
-	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
-	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
+	cpumask_copy(pinst->cpumask.pcpu, cpu_possible_mask);
+	cpumask_copy(pinst->cpumask.cbcpu, cpu_possible_mask);
 
 	if (padata_setup_cpumasks(pinst))
 		goto err_free_masks;
@@ -1057,21 +1048,7 @@ static struct padata_instance *padata_alloc(const char *name,
 err:
 	return NULL;
 }
-
-/**
- * padata_alloc_possible - Allocate and initialize padata instance.
- *                         Use the cpu_possible_mask for serial and
- *                         parallel workers.
- *
- * @name: used to identify the instance
- *
- * Return: new instance on success, NULL on error
- */
-struct padata_instance *padata_alloc_possible(const char *name)
-{
-	return padata_alloc(name, cpu_possible_mask, cpu_possible_mask);
-}
-EXPORT_SYMBOL(padata_alloc_possible);
+EXPORT_SYMBOL(padata_alloc);
 
 /**
  * padata_free - free a padata instance
-- 
2.27.0

[PATCH 6/6] padata: remove padata_parallel_queue

[Daniel Jordan]

Only its reorder field is actually used now, so remove the struct and
embed @reorder directly in parallel_data.

No functional change, just a cleanup.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 include/linux/padata.h | 15 ++------------
 kernel/padata.c        | 46 ++++++++++++++++++------------------------
 2 files changed, 22 insertions(+), 39 deletions(-)

diff --git a/include/linux/padata.h b/include/linux/padata.h
index 070a7d43e8af8..a433f13fc4bf7 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -66,17 +66,6 @@ struct padata_serial_queue {
        struct parallel_data *pd;
 };
 
-/**
- * struct padata_parallel_queue - The percpu padata parallel queue
- *
- * @reorder: List to wait for reordering after parallel processing.
- * @num_obj: Number of objects that are processed by this cpu.
- */
-struct padata_parallel_queue {
-       struct padata_list    reorder;
-       atomic_t              num_obj;
-};
-
 /**
  * struct padata_cpumask - The cpumasks for the parallel/serial workers
  *
@@ -93,7 +82,7 @@ struct padata_cpumask {
  * that depends on the cpumask in use.
  *
  * @ps: padata_shell object.
- * @pqueue: percpu padata queues used for parallelization.
+ * @reorder_list: percpu reorder lists
  * @squeue: percpu padata queues used for serialuzation.
  * @refcnt: Number of objects holding a reference on this parallel_data.
  * @seq_nr: Sequence number of the parallelized data object.
@@ -105,7 +94,7 @@ struct padata_cpumask {
  */
 struct parallel_data {
 	struct padata_shell		*ps;
-	struct padata_parallel_queue	__percpu *pqueue;
+	struct padata_list		__percpu *reorder_list;
 	struct padata_serial_queue	__percpu *squeue;
 	atomic_t			refcnt;
 	unsigned int			seq_nr;
diff --git a/kernel/padata.c b/kernel/padata.c
index 1c0b97891edb8..16cb894dc272b 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -250,13 +250,11 @@ EXPORT_SYMBOL(padata_do_parallel);
 static struct padata_priv *padata_find_next(struct parallel_data *pd,
 					    bool remove_object)
 {
-	struct padata_parallel_queue *next_queue;
 	struct padata_priv *padata;
 	struct padata_list *reorder;
 	int cpu = pd->cpu;
 
-	next_queue = per_cpu_ptr(pd->pqueue, cpu);
-	reorder = &next_queue->reorder;
+	reorder = per_cpu_ptr(pd->reorder_list, cpu);
 
 	spin_lock(&reorder->lock);
 	if (list_empty(&reorder->list)) {
@@ -291,7 +289,7 @@ static void padata_reorder(struct parallel_data *pd)
 	int cb_cpu;
 	struct padata_priv *padata;
 	struct padata_serial_queue *squeue;
-	struct padata_parallel_queue *next_queue;
+	struct padata_list *reorder;
 
 	/*
 	 * We need to ensure that only one cpu can work on dequeueing of
@@ -339,9 +337,8 @@ static void padata_reorder(struct parallel_data *pd)
 	 */
 	smp_mb();
 
-	next_queue = per_cpu_ptr(pd->pqueue, pd->cpu);
-	if (!list_empty(&next_queue->reorder.list) &&
-	    padata_find_next(pd, false))
+	reorder = per_cpu_ptr(pd->reorder_list, pd->cpu);
+	if (!list_empty(&reorder->list) && padata_find_next(pd, false))
 		queue_work(pinst->serial_wq, &pd->reorder_work);
 }
 
@@ -401,17 +398,16 @@ void padata_do_serial(struct padata_priv *padata)
 {
 	struct parallel_data *pd = padata->pd;
 	int hashed_cpu = padata_cpu_hash(pd, padata->seq_nr);
-	struct padata_parallel_queue *pqueue = per_cpu_ptr(pd->pqueue,
-							   hashed_cpu);
+	struct padata_list *reorder = per_cpu_ptr(pd->reorder_list, hashed_cpu);
 	struct padata_priv *cur;
 
-	spin_lock(&pqueue->reorder.lock);
+	spin_lock(&reorder->lock);
 	/* Sort in ascending order of sequence number. */
-	list_for_each_entry_reverse(cur, &pqueue->reorder.list, list)
+	list_for_each_entry_reverse(cur, &reorder->list, list)
 		if (cur->seq_nr < padata->seq_nr)
 			break;
 	list_add(&padata->list, &cur->list);
-	spin_unlock(&pqueue->reorder.lock);
+	spin_unlock(&reorder->lock);
 
 	/*
 	 * Ensure the addition to the reorder list is ordered correctly
@@ -553,17 +549,15 @@ static void padata_init_squeues(struct parallel_data *pd)
 	}
 }
 
-/* Initialize all percpu queues used by parallel workers */
-static void padata_init_pqueues(struct parallel_data *pd)
+/* Initialize per-CPU reorder lists */
+static void padata_init_reorder_list(struct parallel_data *pd)
 {
 	int cpu;
-	struct padata_parallel_queue *pqueue;
+	struct padata_list *list;
 
 	for_each_cpu(cpu, pd->cpumask.pcpu) {
-		pqueue = per_cpu_ptr(pd->pqueue, cpu);
-
-		__padata_list_init(&pqueue->reorder);
-		atomic_set(&pqueue->num_obj, 0);
+		list = per_cpu_ptr(pd->reorder_list, cpu);
+		__padata_list_init(list);
 	}
 }
 
@@ -577,13 +571,13 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 	if (!pd)
 		goto err;
 
-	pd->pqueue = alloc_percpu(struct padata_parallel_queue);
-	if (!pd->pqueue)
+	pd->reorder_list = alloc_percpu(struct padata_list);
+	if (!pd->reorder_list)
 		goto err_free_pd;
 
 	pd->squeue = alloc_percpu(struct padata_serial_queue);
 	if (!pd->squeue)
-		goto err_free_pqueue;
+		goto err_free_reorder_list;
 
 	pd->ps = ps;
 
@@ -595,7 +589,7 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 	cpumask_and(pd->cpumask.pcpu, pinst->cpumask.pcpu, cpu_online_mask);
 	cpumask_and(pd->cpumask.cbcpu, pinst->cpumask.cbcpu, cpu_online_mask);
 
-	padata_init_pqueues(pd);
+	padata_init_reorder_list(pd);
 	padata_init_squeues(pd);
 	pd->seq_nr = -1;
 	atomic_set(&pd->refcnt, 1);
@@ -609,8 +603,8 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 	free_cpumask_var(pd->cpumask.pcpu);
 err_free_squeue:
 	free_percpu(pd->squeue);
-err_free_pqueue:
-	free_percpu(pd->pqueue);
+err_free_reorder_list:
+	free_percpu(pd->reorder_list);
 err_free_pd:
 	kfree(pd);
 err:
@@ -621,7 +615,7 @@ static void padata_free_pd(struct parallel_data *pd)
 {
 	free_cpumask_var(pd->cpumask.pcpu);
 	free_cpumask_var(pd->cpumask.cbcpu);
-	free_percpu(pd->pqueue);
+	free_percpu(pd->reorder_list);
 	free_percpu(pd->squeue);
 	kfree(pd);
 }
-- 
2.27.0

Re: [PATCH 0/6] padata cleanups

[Herbert Xu]

On Tue, Jul 14, 2020 at 04:13:50PM -0400, Daniel Jordan wrote:
> These cleanups save ~5% of the padata text/data and make it a little
> easier to use and develop going forward.
> 
> In particular, they pave the way to extend padata's multithreading support to
> VFIO, a work-in-progress version of which can be found here:
> 
>     https://oss.oracle.com/git/gitweb.cgi?p=linux-dmjordan.git;a=shortlog;h=refs/heads/padata-mt-wip-v0.5
> 
> Based on v5.8-rc5.  As always, feedback is welcome.
> 
> Daniel
> 
> Daniel Jordan (6):
>   padata: remove start function
>   padata: remove stop function
>   padata: inline single call of pd_setup_cpumasks()
>   padata: remove effective cpumasks from the instance
>   padata: fold padata_alloc_possible() into padata_alloc()
>   padata: remove padata_parallel_queue
> 
>  Documentation/core-api/padata.rst |  18 +--
>  crypto/pcrypt.c                   |  17 +--
>  include/linux/padata.h            |  21 +---
>  kernel/padata.c                   | 177 ++++++------------------------
>  4 files changed, 46 insertions(+), 187 deletions(-)

All applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt