Re: [libvirt] [PATCH v4] libvirtd: Increase NL buffer size for lots of interface

1. When switching CPUs to offline/online in a system more than 128 cpus 2. When using virsh to destroy domain in a system with more interface All of above happens nl_recv returned with error: No buffer space available. This patch sets the socket buffer size to 128K and turns on message peeking on new function virNetlinkAlloc,as this would solve this problem totally and permanetly. Signed-off-by: Leno Hou <houqy(a)linux.vnet.ibm.com&gt; Cc: Wenyi Gao <wenyi(a)linux.vnet.ibm.com&gt; CC: Laine Stump <laine(a)laine.org&gt; CC: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/util/virnetlink.c | 42 ++++++++++++++++++++++++++++++++++++++---- src/util/virnetlink.h | 7 +++++++ 2 files changed, 45 insertions(+), 4 deletions(-) diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c index 679b48e..02f5215 100644 --- a/src/util/virnetlink.c +++ b/src/util/virnetlink.c @@ -64,13 +64,11 @@ struct virNetlinkEventHandle { }; # ifdef HAVE_LIBNL1 -# define virNetlinkAlloc nl_handle_alloc +# define virSocketSetBufferSize nl_set_buffer_size # define virNetlinkFree nl_handle_destroy -typedef struct nl_handle virNetlinkHandle; # else -# define virNetlinkAlloc nl_socket_alloc +# define virSocketSetBufferSize nl_socket_set_buffer_size # define virNetlinkFree nl_socket_free -typedef struct nl_sock virNetlinkHandle; # endif typedef struct _virNetlinkEventSrvPrivate virNetlinkEventSrvPrivate; @@ -108,6 +106,42 @@ static virNetlinkHandle *placeholder_nlhandle; /* Function definitions */ /** + * virNetlinkAlloc + * + * Perform netlink allocation which was defined differently for libnl3 + * vs libnl-1, and did all of three in one function + * 1) create socket + * 2) set larger buffer size + * 3) turn on message peeking + * + * see the following email message: + * https://www.redhat.com/archives/libvir-list/2016-January/msg00536.html + * + * Returns virNetlinkHandle + */ +virNetlinkHandle *virNetlinkAlloc(void) +{ + virNetlinkHandle *netlinknh; + #ifdef HAVE_LIBNL1 + netlinknh = nl_handle_alloc(); + #else + netlinknh = nl_socket_alloc(); + #endif + + if (virSocketSetBufferSize(netlinknh,131702,0) >= 0) { + nl_socket_enable_msg_peek(netlinknh); + return netlinknh; + } + + virReportSystemError(errno, + "%s",_("can not set socket buffer size to 128k")); + + virNetlinkFree(netlinknh); + + return NULL; +} + +/** * virNetlinkStartup: * * Perform any initialization that needs to take place before the diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h index 0664a7a..b4a2010 100644 --- a/src/util/virnetlink.h +++ b/src/util/virnetlink.h @@ -44,6 +44,13 @@ struct nlmsghdr; # endif /* __linux__ */ +# ifdef HAVE_LIBNL1 +typedef struct nl_handle virNetlinkHandle; +# else +typedef struct nl_sock virNetlinkHandle; +# endif +virNetlinkHandle *virNetlinkAlloc(void); + int virNetlinkStartup(void); void virNetlinkShutdown(void);