On 2010-09-24 21:20, Malahal Naineni wrote: > Jens Axboe [jaxboe@xxxxxxxxxxxx] wrote: >>> This patch also _fixed_ our problem. So we are fine with either patch, >>> but this patch is preferred as it enables more request merges. Also, >>> both patches maybe needed for some configurations. >> >> Plus it doesn't needlessly bounce, that's the real problem you want to >> fix. I have applied this thread patch to for-2.6.37/core, thanks. > > There is a shortcut check in blk_queue_bounce() that uses blk_max_pfn to > return without doing anything. blk_max_pfn is not updated when we do > hot-plug memory add, so bounce buffers are NOT really used in our case > (thankfully)! Any reason we can't just add a hot mem add notifier and update the block copies when we need to? -- Jens Axboe -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
