Hi, On 2016/01/07 0:26, Taylor R Campbell wrote: > Date: Wed, 6 Jan 2016 14:19:01 +0900 > From: Kengo NAKAHARA <k-nakah...@iij.ad.jp> > > I have a question for confirmation. If the struct has two locks for > different purposes, is the COHERENCY_UNIT padding required between > the locks isn't it? E.g. in my old patch(gif-mp-ify.patch), is the > COHERENCY_UNIT padding is required between gif_lock and struct si_sync > which has other lock(si_lock)? > # BTW, struct si_sync is removed by if_gif.h:r1.21 > > That may be a good idea if you expect simultaneous use of both locks > independently -- as in struct pcq. But without that analysis, it is > likely premature optimization, and the wrangling of COHERENCY_UNIT > alignment inside a struct is more trouble than it's worth. In > contrast, for global locks, the __cacheline_aligned attribute is no > trouble at all.
I see. I will analyze carefully if I want to use COHERENCY_UNIT inside struct. Thank you very much! Thanks, -- ////////////////////////////////////////////////////////////////////// Internet Initiative Japan Inc. Device Engineering Section, Core Product Development Department, Product Division, Technology Unit Kengo NAKAHARA <k-nakah...@iij.ad.jp>