Messages in this thread | | | From | David Brownell <> | Subject | Re: [PATCH 6/7] mmc_spi: convert timeout handling to jiffies and avoid busy waiting | Date | Wed, 11 Mar 2009 18:45:22 -0800 |
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On Wednesday 11 March 2009, Wolfgang Mües wrote: > o SD/MMC card timeouts can be very high. So avoid busy-waiting, > using the scheduler. Calculate all timeouts in jiffies units, > because this will give us the correct sign when to involve > the scheduler.
Of these patches, this is the one that bothers me the most.
First, earlier versions used jiffies ... but switching to ktime sped things up. (I forget the details by now.) So it's odd to think that switching again could improve things. At any rate, if that's worth doing it's worth having as a separate patch.
Second, as someone previously pointed out, there's a comment there about switching to sleep() calls ... did you explore just kicking in schedule_hrtimeout() or somesuch, right at that point? Heck, just calling schedule() would cut the busy-wait overhead...
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