Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 22 Jun 2014 11:32:23 +0000 (UTC)
From:      "Alexander V. Chernikov" <melifaro@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r267716 - in head/sys: kern sys
Message-ID:  <201406221132.s5MBWNWj097084@svn.freebsd.org>

next in thread | raw e-mail | index | archive | help
Author: melifaro
Date: Sun Jun 22 11:32:23 2014
New Revision: 267716
URL: http://svnweb.freebsd.org/changeset/base/267716

Log:
  Permit changing cpu mask for cpu set 1 in presence of drivers
  binding their threads to particular CPU.
  
  Changing ithread cpu mask is now performed by special cpuset_setithread().
  It creates additional cpuset root group on first bind invocation.
  
  No objection:	jhb
  Tested by:	hiren
  MFC after:	2 weeks
  Sponsored by:	Yandex LLC

Modified:
  head/sys/kern/kern_cpuset.c
  head/sys/kern/kern_intr.c
  head/sys/sys/cpuset.h

Modified: head/sys/kern/kern_cpuset.c
==============================================================================
--- head/sys/kern/kern_cpuset.c	Sun Jun 22 10:00:33 2014	(r267715)
+++ head/sys/kern/kern_cpuset.c	Sun Jun 22 11:32:23 2014	(r267716)
@@ -106,7 +106,7 @@ static uma_zone_t cpuset_zone;
 static struct mtx cpuset_lock;
 static struct setlist cpuset_ids;
 static struct unrhdr *cpuset_unr;
-static struct cpuset *cpuset_zero;
+static struct cpuset *cpuset_zero, *cpuset_default;
 
 /* Return the size of cpuset_t at the kernel level */
 SYSCTL_INT(_kern_sched, OID_AUTO, cpusetsize, CTLFLAG_RD,
@@ -716,6 +716,89 @@ out:
 }
 
 /*
+ * Apply new cpumask to the ithread.
+ */
+int
+cpuset_setithread(lwpid_t id, u_char cpu)
+{
+	struct cpuset *nset, *rset;
+	struct cpuset *parent, *old_set;
+	struct thread *td;
+	struct proc *p;
+	cpusetid_t cs_id;
+	cpuset_t mask;
+	int error;
+
+	nset = uma_zalloc(cpuset_zone, M_WAITOK);
+	rset = uma_zalloc(cpuset_zone, M_WAITOK);
+
+	CPU_ZERO(&mask);
+	if (cpu == NOCPU)
+		CPU_COPY(cpuset_root, &mask);
+	else
+		CPU_SET(cpu, &mask);
+
+	error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &old_set);
+	if (((cs_id = alloc_unr(cpuset_unr)) == CPUSET_INVALID) || error != 0)
+		goto out;
+
+	thread_lock(td);
+	old_set = td->td_cpuset;
+
+	if (cpu == NOCPU) {
+		/*
+		 * roll back to default set. We're not using cpuset_shadow()
+		 * here because we can fail CPU_SUBSET() check. This can happen
+		 * if default set does not contain all CPUs.
+		 */
+		error = _cpuset_create(nset, cpuset_default, &mask,
+		    CPUSET_INVALID);
+
+		goto applyset;
+	}
+
+	if (old_set->cs_id == 1 || (old_set->cs_id == CPUSET_INVALID &&
+	    old_set->cs_parent->cs_id == 1)) {
+		/* Default mask, we need to use new root set */
+		error = _cpuset_create(rset, cpuset_zero,
+		    &cpuset_zero->cs_mask, cs_id);
+		if (error != 0) {
+			PROC_UNLOCK(p);
+			goto out;
+		}
+		rset->cs_flags |= CPU_SET_ROOT;
+		parent = rset;
+		rset = NULL;
+		cs_id = CPUSET_INVALID;
+	} else {
+		/* Assume existing set was already allocated by previous call */
+		parent = td->td_cpuset;
+		old_set = NULL;
+	}
+
+	error = cpuset_shadow(parent, nset, &mask);
+applyset:
+	if (error == 0) {
+		td->td_cpuset = nset;
+		sched_affinity(td);
+		nset = NULL;
+	}
+	thread_unlock(td);
+	PROC_UNLOCK(p);
+	if (old_set != NULL)
+		cpuset_rel(old_set);
+out:
+	if (nset != NULL)
+		uma_zfree(cpuset_zone, nset);
+	if (rset != NULL)
+		uma_zfree(cpuset_zone, rset);
+	if (cs_id != CPUSET_INVALID)
+		free_unr(cpuset_unr, cs_id);
+	return (error);
+}
+
+
+/*
  * Creates the cpuset for thread0.  We make two sets:
  * 
  * 0 - The root set which should represent all valid processors in the
@@ -735,6 +818,7 @@ cpuset_thread0(void)
 	cpuset_zone = uma_zcreate("cpuset", sizeof(struct cpuset), NULL, NULL,
 	    NULL, NULL, UMA_ALIGN_PTR, 0);
 	mtx_init(&cpuset_lock, "cpuset", NULL, MTX_SPIN | MTX_RECURSE);
+
 	/*
 	 * Create the root system set for the whole machine.  Doesn't use
 	 * cpuset_create() due to NULL parent.
@@ -747,12 +831,15 @@ cpuset_thread0(void)
 	set->cs_flags = CPU_SET_ROOT;
 	cpuset_zero = set;
 	cpuset_root = &set->cs_mask;
+
 	/*
 	 * Now derive a default, modifiable set from that to give out.
 	 */
 	set = uma_zalloc(cpuset_zone, M_WAITOK);
 	error = _cpuset_create(set, cpuset_zero, &cpuset_zero->cs_mask, 1);
 	KASSERT(error == 0, ("Error creating default set: %d\n", error));
+	cpuset_default = set;
+
 	/*
 	 * Initialize the unit allocator. 0 and 1 are allocated above.
 	 */

Modified: head/sys/kern/kern_intr.c
==============================================================================
--- head/sys/kern/kern_intr.c	Sun Jun 22 10:00:33 2014	(r267715)
+++ head/sys/kern/kern_intr.c	Sun Jun 22 11:32:23 2014	(r267716)
@@ -295,7 +295,6 @@ intr_event_create(struct intr_event **ev
 int
 intr_event_bind(struct intr_event *ie, u_char cpu)
 {
-	cpuset_t mask;
 	lwpid_t id;
 	int error;
 
@@ -316,14 +315,9 @@ intr_event_bind(struct intr_event *ie, u
 	 */
 	mtx_lock(&ie->ie_lock);
 	if (ie->ie_thread != NULL) {
-		CPU_ZERO(&mask);
-		if (cpu == NOCPU)
-			CPU_COPY(cpuset_root, &mask);
-		else
-			CPU_SET(cpu, &mask);
 		id = ie->ie_thread->it_thread->td_tid;
 		mtx_unlock(&ie->ie_lock);
-		error = cpuset_setthread(id, &mask);
+		error = cpuset_setithread(id, cpu);
 		if (error)
 			return (error);
 	} else
@@ -332,14 +326,10 @@ intr_event_bind(struct intr_event *ie, u
 	if (error) {
 		mtx_lock(&ie->ie_lock);
 		if (ie->ie_thread != NULL) {
-			CPU_ZERO(&mask);
-			if (ie->ie_cpu == NOCPU)
-				CPU_COPY(cpuset_root, &mask);
-			else
-				CPU_SET(ie->ie_cpu, &mask);
+			cpu = ie->ie_cpu;
 			id = ie->ie_thread->it_thread->td_tid;
 			mtx_unlock(&ie->ie_lock);
-			(void)cpuset_setthread(id, &mask);
+			(void)cpuset_setithread(id, cpu);
 		} else
 			mtx_unlock(&ie->ie_lock);
 		return (error);

Modified: head/sys/sys/cpuset.h
==============================================================================
--- head/sys/sys/cpuset.h	Sun Jun 22 10:00:33 2014	(r267715)
+++ head/sys/sys/cpuset.h	Sun Jun 22 11:32:23 2014	(r267716)
@@ -118,6 +118,7 @@ struct cpuset *cpuset_thread0(void);
 struct cpuset *cpuset_ref(struct cpuset *);
 void	cpuset_rel(struct cpuset *);
 int	cpuset_setthread(lwpid_t id, cpuset_t *);
+int	cpuset_setithread(lwpid_t id, u_char cpu);
 int	cpuset_create_root(struct prison *, struct cpuset **);
 int	cpuset_setproc_update_set(struct proc *, struct cpuset *);
 char	*cpusetobj_strprint(char *, const cpuset_t *);



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201406221132.s5MBWNWj097084>