[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] Simpler domid allocation.
# HG changeset patch # User kaf24@xxxxxxxxxxxxxxxxxxxx # Node ID 8d04aa7b42805d6d15c651abe13249c4d2eefaf7 # Parent 1d026c7023d28aad1a409638d4f1db518a80bdfd Simpler domid allocation. Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx> diff -r 1d026c7023d2 -r 8d04aa7b4280 xen/common/dom0_ops.c --- a/xen/common/dom0_ops.c Thu Jul 14 23:48:06 2005 +++ b/xen/common/dom0_ops.c Fri Jul 15 07:53:46 2005 @@ -37,55 +37,6 @@ put_domain(d); return 0; -} - -/* - * Allocate a free domain id. We try to reuse domain ids in a fairly low range, - * only expanding the range when there are no free domain ids. This is to keep - * domain ids in a range depending on the number that exist simultaneously, - * rather than incrementing domain ids in the full 32-bit range. - */ -static int allocate_domid(domid_t *pdom) -{ - static spinlock_t domid_lock = SPIN_LOCK_UNLOCKED; - static domid_t curdom = 0; - static domid_t topdom = 101; - int err = 0; - domid_t dom; - - spin_lock(&domid_lock); - - /* Try to use a domain id in the range 0..topdom, starting at curdom. */ - for ( dom = curdom + 1; dom != curdom; dom++ ) - { - if ( dom == topdom ) - dom = 1; - if ( is_free_domid(dom) ) - goto exit; - } - - /* Couldn't find a free domain id in 0..topdom, try higher. */ - for ( dom = topdom; dom < DOMID_FIRST_RESERVED; dom++ ) - { - if ( is_free_domid(dom) ) - { - topdom = dom + 1; - goto exit; - } - } - - /* No free domain ids. */ - err = -ENOMEM; - - exit: - if ( err == 0 ) - { - curdom = dom; - *pdom = dom; - } - - spin_unlock(&domid_lock); - return err; } static void getdomaininfo(struct domain *d, dom0_getdomaininfo_t *info) @@ -217,18 +168,33 @@ domid_t dom; struct vcpu *v; unsigned int i, cnt[NR_CPUS] = { 0 }; - + static spinlock_t alloc_lock = SPIN_LOCK_UNLOCKED; + static domid_t rover = 0; + + spin_lock(&alloc_lock); dom = op->u.createdomain.domain; if ( (dom > 0) && (dom < DOMID_FIRST_RESERVED) ) { ret = -EINVAL; if ( !is_free_domid(dom) ) - break; - } - else if ( (ret = allocate_domid(&dom)) != 0 ) - { - break; + goto alloc_out; + } + else + { + for ( dom = rover + 1; dom != rover; dom++ ) + { + if ( dom == DOMID_FIRST_RESERVED ) + dom = 0; + if ( is_free_domid(dom) ) + break; + } + + ret = -ENOMEM; + if ( dom == rover ) + goto alloc_out; + + rover = dom; } /* Do an initial CPU placement. Pick the least-populated CPU. */ @@ -249,11 +215,12 @@ pro = i; ret = -ENOMEM; - if ( (d = do_createdomain(dom, pro)) == NULL ) - break; - - ret = 0; - + if ( (d = do_createdomain(dom, pro)) != NULL ) + ret = 0; + + alloc_out: + spin_unlock(&alloc_lock); + op->u.createdomain.domain = d->domain_id; copy_to_user(u_dom0_op, op, sizeof(*op)); } _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |