diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/vas.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/vas.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index ba3fb7a7f2ea..c25eb1a38185 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/arch/powerpc/platforms/pseries/vas.c @@ -38,7 +38,27 @@ static long hcall_return_busy_check(long rc) { /* Check if we are stalled for some time */ if (H_IS_LONG_BUSY(rc)) { - msleep(get_longbusy_msecs(rc)); + unsigned int ms; + /* + * Allocate, Modify and Deallocate HCALLs returns + * H_LONG_BUSY_ORDER_1_MSEC or H_LONG_BUSY_ORDER_10_MSEC + * for the long delay. So the sleep time should always + * be either 1 or 10msecs, but in case if the HCALL + * returns the long delay > 10 msecs, clamp the sleep + * time to 10msecs. + */ + ms = clamp(get_longbusy_msecs(rc), 1, 10); + + /* + * msleep() will often sleep at least 20 msecs even + * though the hypervisor suggests that the OS reissue + * HCALLs after 1 or 10msecs. Also the delay hint from + * the HCALL is just a suggestion. So OK to pause for + * less time than the hinted delay. Use usleep_range() + * to ensure we don't sleep much longer than actually + * needed. + */ + usleep_range(ms * (USEC_PER_MSEC / 10), ms * USEC_PER_MSEC); rc = H_BUSY; } else if (rc == H_BUSY) { cond_resched(); |