KAMEZAWA Hiroyuki wrote: > On Tue, 04 Dec 2007 14:10:42 +0300 > Pavel Emelyanov <xemul@xxxxxxxxxx> wrote: > >> KAMEZAWA Hiroyuki wrote: >>> This is seqlock version res_counter. >>> Maybe this this will reduce # of spin_lock. >>> >>> Pavel-san, How about this ? >> AFAIS the readlock is used only in the check_under_limit(), >> but I think, that even if we read usage and limit values >> in this case non-atomically, this won't result in any >> dramatic sequence at all. No? >> > Reader can detect *any* changes in res_counter member which happens > while they access res_counter between seq_begin/seq_retry. > Memory barrier and "sequence" of seq_lock guarantees this. > So..there is no dramatical situation. > (it's used for accesing xtime.) > > I'm sorry if I miss your point. Sorry, let me explain it in other words. I think, that protection in reader, that guarantees that it will see the valid result, is not very important - even if we compare usage and limit not atomically nothing serious will happen (in this particular case) > Thanks, > -Kame > > _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers