Date: Wed, 25 Nov 2020 01:42:33 +0000 (UTC) From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r368009 - head/sys/kern Message-ID: <202011250142.0AP1gXav020738@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kevans Date: Wed Nov 25 01:42:32 2020 New Revision: 368009 URL: https://svnweb.freebsd.org/changeset/base/368009 Log: kern: cpuset: allow cpuset_create() to take an allocated *setp Currently, it must always allocate a new set to be used for passing to _cpuset_create, but it doesn't have to. This is purely kern_cpuset.c internal and it's sparsely used, so just change it to use *setp if it's not-NULL and modify the two consumers to pass in the address of a NULL cpuset. This paves the way for consumers that want the unr allocation without the possibility of sleeping as long as they've done their due diligence to ensure that the mask will properly apply atop the supplied parent (i.e. avoiding the free_unr() in the last failure path). Reviewed by: jamie, markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D27297 Modified: head/sys/kern/kern_cpuset.c Modified: head/sys/kern/kern_cpuset.c ============================================================================== --- head/sys/kern/kern_cpuset.c Wed Nov 25 01:31:00 2020 (r368008) +++ head/sys/kern/kern_cpuset.c Wed Nov 25 01:42:32 2020 (r368009) @@ -326,6 +326,10 @@ _cpuset_create(struct cpuset *set, struct cpuset *pare * Create a new non-anonymous set with the requested parent and mask. May * return failures if the mask is invalid or a new number can not be * allocated. + * + * If *setp is not NULL, then it will be used as-is. The caller must take + * into account that *setp will be inserted at the head of cpuset_ids and + * plan any potentially conflicting cs_link usage accordingly. */ static int cpuset_create(struct cpuset **setp, struct cpuset *parent, const cpuset_t *mask) @@ -333,16 +337,22 @@ cpuset_create(struct cpuset **setp, struct cpuset *par struct cpuset *set; cpusetid_t id; int error; + bool dofree; id = alloc_unr(cpuset_unr); if (id == -1) return (ENFILE); - *setp = set = uma_zalloc(cpuset_zone, M_WAITOK | M_ZERO); + dofree = (*setp == NULL); + if (*setp != NULL) + set = *setp; + else + *setp = set = uma_zalloc(cpuset_zone, M_WAITOK | M_ZERO); error = _cpuset_create(set, parent, mask, NULL, id); if (error == 0) return (0); free_unr(cpuset_unr, id); - uma_zfree(cpuset_zone, set); + if (dofree) + uma_zfree(cpuset_zone, set); return (error); } @@ -1552,16 +1562,17 @@ cpuset_create_root(struct prison *pr, struct cpuset ** KASSERT(pr != NULL, ("[%s:%d] invalid pr", __func__, __LINE__)); KASSERT(setp != NULL, ("[%s:%d] invalid setp", __func__, __LINE__)); - error = cpuset_create(setp, pr->pr_cpuset, &pr->pr_cpuset->cs_mask); + set = NULL; + error = cpuset_create(&set, pr->pr_cpuset, &pr->pr_cpuset->cs_mask); if (error) return (error); - KASSERT(*setp != NULL, ("[%s:%d] cpuset_create returned invalid data", + KASSERT(set != NULL, ("[%s:%d] cpuset_create returned invalid data", __func__, __LINE__)); /* Mark the set as root. */ - set = *setp; set->cs_flags |= CPU_SET_ROOT; + *setp = set; return (0); } @@ -1618,6 +1629,7 @@ sys_cpuset(struct thread *td, struct cpuset_args *uap) thread_lock(td); root = cpuset_refroot(td->td_cpuset); thread_unlock(td); + set = NULL; error = cpuset_create(&set, root, &root->cs_mask); cpuset_rel(root); if (error)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202011250142.0AP1gXav020738>