• Pavel Emelyanov's avatar
    bfd: Implement buffered reads · 8651f43b
    Pavel Emelyanov authored
    The restore times look like
    
    Before patch:
    	  futex:      370  3.554482 (84.2%)
    	 umount:       41  0.234796 (5.6%)
    	   read:     4737  0.113987 (2.7%)
    	recvmsg:       43  0.100083 (2.4%)
    	  wait4:       10  0.033344 (0.8%)
    
    After patch:
    	  futex:      187  1.547642 (72.9%)
    	 umount:       41  0.234595 (11.0%)
    	recvmsg:       43  0.075738 (3.6%)
    	  flock:       42  0.038696 (1.8%)
    	  clone:       35  0.037699 (1.8%)
    
    Most of the time we wait for other processes to restore,
    but that's OK (would only affect parallel restore). And
    we see that read-s really go away (onto 7th position).
    Signed-off-by: 's avatarPavel Emelyanov <xemul@parallels.com>
    Acked-by: 's avatarCyrill Gorcunov <gorcunov@openvz.org>
    8651f43b
bfd.c 5.08 KB