diff --git a/tools/libxc/xc_cpupool.c b/tools/libxc/xc_cpupool.c index c42273e541..261b9c956e 100644 --- a/tools/libxc/xc_cpupool.c +++ b/tools/libxc/xc_cpupool.c @@ -20,6 +20,7 @@ */ #include +#include #include "xc_private.h" static int do_sysctl_save(xc_interface *xch, struct xen_sysctl *sysctl) @@ -137,17 +138,34 @@ int xc_cpupool_addcpu(xc_interface *xch, return do_sysctl_save(xch, &sysctl); } +/* + * The hypervisor might return EBUSY when trying to remove a cpu from a + * cpupool when a domain running in this cpupool has pinned a vcpu + * temporarily. Do some retries in this case, perhaps the situation + * cleans up. + */ +#define NUM_RMCPU_BUSY_RETRIES 5 + int xc_cpupool_removecpu(xc_interface *xch, uint32_t poolid, int cpu) { + unsigned retries; + int err; DECLARE_SYSCTL; sysctl.cmd = XEN_SYSCTL_cpupool_op; sysctl.u.cpupool_op.op = XEN_SYSCTL_CPUPOOL_OP_RMCPU; sysctl.u.cpupool_op.cpupool_id = poolid; sysctl.u.cpupool_op.cpu = (cpu < 0) ? XEN_SYSCTL_CPUPOOL_PAR_ANY : cpu; - return do_sysctl_save(xch, &sysctl); + for ( retries = 0; retries < NUM_RMCPU_BUSY_RETRIES; retries++ ) { + err = do_sysctl_save(xch, &sysctl); + if ( err < 0 && errno == EBUSY ) + sleep(1); + else + break; + } + return err; } int xc_cpupool_movedomain(xc_interface *xch,