• Eric Dumazet's avatar
    [NET]: convert network timestamps to ktime_t · b7aa0bf7
    Eric Dumazet authored
    We currently use a special structure (struct skb_timeval) and plain
    'struct timeval' to store packet timestamps in sk_buffs and struct
    sock.
    
    This has some drawbacks :
    - Fixed resolution of micro second.
    - Waste of space on 64bit platforms where sizeof(struct timeval)=16
    
    I suggest using ktime_t that is a nice abstraction of high resolution
    time services, currently capable of nanosecond resolution.
    
    As sizeof(ktime_t) is 8 bytes, using ktime_t in 'struct sock' permits
    a 8 byte shrink of this structure on 64bit architectures. Some other
    structures also benefit from this size reduction (struct ipq in
    ipv4/ip_fragment.c, struct frag_queue in ipv6/reassembly.c, ...)
    
    Once this ktime infrastructure adopted, we can more easily provide
    nanosecond resolution on top of it. (ioctl SIOCGSTAMPNS and/or
    SO_TIMESTAMPNS/SCM_TIMESTAMPNS)
    
    Note : this patch includes a bug correction in
    compat_sock_get_timestamp() where a "err = 0;" was missing (so this
    syscall returned -ENOENT instead of 0)
    Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
    CC: Stephen Hemminger <shemminger@linux-foundation.org>
    CC: John find <linux.kernel@free.fr>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    b7aa0bf7
compat.c 18.6 KB