On Thu, Jun 10, 2010 at 11:16:14AM -0600, Eric Blake wrote:
* src/remote/remote_driver.c (remoteDomainCreate): Rewrite to take 1 RPC instead of 2 when talking to newer server, at expense of 3 RPC instead of 2 for older server. ---
I had already started coding this, but then Daniel Berrange reminded me off-list that changing existing API just for a minor optimization in the number of RPC calls is not a good idea: clients (like virsh) are already free to do the optimization themselves, and libvirt RPC calls tend not to be the critical path in the system in the first place.
So, I'm posting this to have it archived, before nuking the commit from my repo.
src/remote/remote_driver.c | 20 ++++++++++++++++++++ 1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 7052bf1..a613ead 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -3001,6 +3001,8 @@ static int remoteDomainCreate (virDomainPtr domain) { int rv = -1; + remote_domain_create_with_flags_args args0; + remote_domain_create_with_flags_ret ret0; remote_domain_create_args args; remote_domain_lookup_by_uuid_args args2; remote_domain_lookup_by_uuid_ret ret2; @@ -3008,6 +3010,24 @@ remoteDomainCreate (virDomainPtr domain)
remoteDriverLock(priv);
+ /* First, try the newer API, for fewer call()s. */ + make_nonnull_domain (&args0.dom, domain); + args0.flags = 0; + + memset (&ret0, 0, sizeof ret0); + if (call (domain->conn, priv, 0, REMOTE_PROC_DOMAIN_CREATE_WITH_FLAGS, + (xdrproc_t) xdr_remote_domain_create_with_flags_args, + (char *) &args0, + (xdrproc_t) xdr_remote_domain_create_with_flags_ret, + (char *) &ret0) == 0) { + domain->id = ret0.dom.id; + xdr_free ((xdrproc_t) &xdr_remote_domain_create_with_flags_ret, + (char *) &ret0); + rv = 0; + goto done; + } + + /* Fall back to the older 2-call sequence. */ make_nonnull_domain (&args.dom, domain);
if (call (domain->conn, priv, 0, REMOTE_PROC_DOMAIN_CREATE,
NACK, this is not required. The existing method is guarenteed to always exist, so there is no benefit to calling the new method & it adds an extra RPC call when talking to old servers Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|