VirtualBox

Changeset 52619 in vbox


Ignore:
Timestamp:
Sep 5, 2014 12:10:24 PM (10 years ago)
Author:
vboxsync
Message:

HostDrivers/support: nits.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • trunk/src/VBox/HostDrivers/Support/SUPDrv.c

    r52618 r52619  
    112112/** Worker thread is done updating TSC delta info. */
    113113#define GIP_TSC_DELTA_SYNC_WORKER_DONE      3
    114 /** When IPRT is isn't concurrent safe: Master is ready and will wait for slave
     114/** When IPRT is isn't concurrent safe: Master is ready and will wait for worker
    115115 *  with a timeout. */
    116116#define GIP_TSC_DELTA_SYNC_PRESTART_MASTER  4
     
    60366036 *     is no guaranteed way of doing this on x86 CPUs. We try to minimize the
    60376037 *     measurement error by computing the minimum read time of the compare
    6038  *     statement in the slave by taking TSC measurements across it. We also
     6038 *     statement in the worker by taking TSC measurements across it. We also
    60396039 *     ignore the first few runs of the loop in order to prime the cache.
    60406040 *
    60416041 *     It must be noted that the computed minimum read time is mostly to
    6042  *     eliminate huge deltas when the slave is too early and doesn't by itself
     6042 *     eliminate huge deltas when the worker is too early and doesn't by itself
    60436043 *     help produce more accurate deltas. We allow two times the computed
    60446044 *     minimum as an arbibtrary acceptable threshold. Therefore, it is still
    6045  *     possible to get negative deltas where there are none when the slave is
     6045 *     possible to get negative deltas where there are none when the worker is
    60466046 *     earlier.
    60476047 */
     
    61636163                 * Keep reading the TSC until we notice that the master has read his. Reading
    61646164                 * the TSC -after- the master has updated the memory is way too late. We thus
    6165                  * compensate by trying to measure how long it took for the slave to notice
     6165                 * compensate by trying to measure how long it took for the worker to notice
    61666166                 * the memory flushed from the master.
    61676167                 */
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