>> Thanx for the patch, but for the next time: How should I apply it? >> it seems to be context aware (@@) and broke on all kernel versions I tried >> 2.6.28/2.6.28.7/2.6.29 > > Do you mean that the patch applies after removing " @@.*$"? I didn't try that, but this time it worked. So it was probably my error. > > You are right. In your case, there are several big dirty files in sdb1, > and the sdb write queue is constantly (almost-)congested. The SSD write > speed is so slow, that in each round of sdb1 writeback, it begins with > an uncongested queue, but quickly fills up after writing some pages. > Hence all the inodes will get redirtied because of (nr_to_write > 0). > > The following quick fix should solve the slow-writeback-on-congested-SSD > problem. However the writeback sequence is suboptimal: it sync-and-requeue > each file until congested (in your case about 3~600 pages) instead of > until MAX_WRITEBACK_PAGES=1024 pages. Yeah that fixed it, but performance dropped due to the more constant congestion. So I will need to try some different io schedulers. Next to that I was wondering if there are any plans to make sure that not all dirty-files are written back in the same interval. In my case all database files are written back each 30 seconds, while I would prefer them to be more divided over the interval. Thanks, Jos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
