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    SubjectHow is Code in do_sys_settimeofday() safe in case of SMP and Nest Kernel Path?
    Hi, all,

    I got a question, that is, I am confused by the following code in

    if (tz) {
    /* SMP safe, global irq locking makes it work. */
    sys_tz = *tz;
    if (firsttime) {
    firsttime = 0;
    if (!tv)

    For my understanding, an assignment between structs should be a
    bit-wise copy. Such operation is not atomic, so it can not be supposed
    SMP-safe. And the subsequent test-and-assign operation on firsttime is
    not atomic, either.

    If the comments mean the subsequent code is SMP-safe and can prevent
    nest-kernel-path, how does it achieves that?

    Thank you in advance.
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      Last update: 2006-09-29 16:37    [W:0.019 / U:13.376 seconds]
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