Yogesh Pahilwan wrote:
Thanks for your reply. As far as what I understood that when we apply the bitmap patch, for every write it will do 2 sync writes that is setting the dirty bit, writing intent log and one async write for clearing the dirty bit. Is it correct?
The bits are in the intent log, so the "setting dirty bit" and "writing intent log" are the same thing. Just one write.
If that is the case are there any patches available which can do collection of sync write in a queue and write a collection in single write request. For Eg: For 10 writes , we will have 10 + 1 sync writes + 10 async write.
The bitmap code already does this by default. The bitmap writes are queued up so that all writes to a given page (within a short time period) are reduced to a single write. The performance is actually quite good. There's very little performance difference between having a bitmap versus not having one.
I mean to say , 10 sync writes for setting the dirty bits + 1 sync write for write intent log for all queued request in one write operation + 10 async write for clearing the dirty bit.
The async writes for clearing the bitmap are also combined. -- Paul - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
