Posted May 12, 2011 18:07 UTC (Thu) by davecb (subscriber, #1574)
In reply to: Stable pages by djwong
Parent article: Stable pages
Perhaps I'm misunderstanding, but won't a series of small sequential writes trigger wait-on-writeback? Or does this not apply to appending to a file-backed page?
In a previous life I was involved in the performance measurement of coalescing disk writes, and we found a very large number of sequential writes could be coalesced into single writes, and then adjacent blocks coalesced into larger singe writes. This paid off particularly well when a disk was being handed writes at or beyond it's capacity, by removing unneeded writes. I think I still have the graphs somewhere (;-))
I'll comment on the non-sequential case in a sec, after I look at my archive.