On Thu, Aug 07, 2014 at 10:11:14AM +0800, Zhang Yanfei wrote: > Hi Joonsoo, > > On 08/06/2014 03:18 PM, Joonsoo Kim wrote: > > per cpu pages structure, aka pcp, has high and batch values to control > > how many pages we perform caching. This values could be updated > > asynchronously and updater should ensure that this doesn't make any > > problem. For this purpose, pageset_update() is implemented and do some > > memory synchronization. But, it turns out to be wrong when I implemented > > new feature using this. There is no corresponding smp_rmb() in read-side > > Out of curiosity, what new feature are you implementing? I mean just zone_pcp_disable() and zone_pcp_enable(). :) > IIRC, pageset_update() is used to update high and batch which can be changed > during: > > system boot > sysfs > memory hot-plug > > So it seems to me that the latter two would have the problems you described here. Yes, I think so. But I'm not sure, because I didn't look at it in detail. :) Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>