On 08.08.2018 19:23, Kirill Tkhai wrote: > On 08.08.2018 19:13, Josh Triplett wrote: >> On Wed, Aug 08, 2018 at 01:17:44PM +0300, Kirill Tkhai wrote: >>> On 08.08.2018 10:20, Michal Hocko wrote: >>>> On Tue 07-08-18 18:37:36, Kirill Tkhai wrote: >>>>> This patch kills all CONFIG_SRCU defines and >>>>> the code under !CONFIG_SRCU. >>>> >>>> The last time somebody tried to do this there was a pushback due to >>>> kernel tinyfication. So this should really give some numbers about the >>>> code size increase. Also why can't we make this depend on MMU. Is >>>> anybody else than the reclaim asking for unconditional SRCU usage? >>> >>> I don't know one. The size numbers (sparc64) are: >>> >>> $ size image.srcu.disabled >>> text data bss dec hex filename >>> 5117546 8030506 1968104 15116156 e6a77c image.srcu.disabled >>> $ size image.srcu.enabled >>> text data bss dec hex filename >>> 5126175 8064346 1968104 15158625 e74d61 image.srcu.enabled >>> The difference is: 15158625-15116156 = 42469 ~41Kb >> >> 41k is a *substantial* size increase. However, can you compare >> tinyconfig with and without this patch? That may have a smaller change. > > $ size image.srcu.disabled > text data bss dec hex filename > 1105900 195456 63232 1364588 14d26c image.srcu.disabled > > $ size image.srcu.enabled > text data bss dec hex filename > 1106960 195528 63232 1365720 14d6d8 image.srcu.enabled > > 1365720-1364588 = 1132 ~ 1Kb 1Kb is not huge size. It looks as not a big price for writing generic code for only case (now some places have CONFIG_SRCU and !CONFIG_SRCU variants, e.g. drivers/base/core.c). What do you think?
