On 7/30/06, Pavel Machek <pavel@xxxxxxx> wrote:
OTOH some applications just want more frequent polling than others. Shem's "first update after N msec" solution looks most flexible here.
Actually my solution was "any update but no sooner than N msecs". So you might be getting a readout that's N-1 msecs old, which was meanwhile cached by the driver. If you care about that, you need to use interleave those polls with msleep()s; see my recent detailed post. You'll still doing at most one msleep() per fetched readout, regardless of how frequently the driver provides them. Alternatively, we can add an extra parameter to that new syscall/ioctl: "block until the time is T+N and you have a refresh that was received from the hardware at time T+M, whichever is later" (where T is the current time and N>M). That's semantically equivalent to an msleep(M) followed by the original delayed_update(N-M), but will save one timer interrupt per iteration in some cases (e.g., an event-based hardware data source). Shem - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
