> On Sun, Jun 19, 2022 at 01:31:37AM +0900, Masami Hiramatsu wrote: > On Wed, 15 Jun 2022 23:15:59 +0200 > Dmitrii Dolgov <9erthalion6@xxxxxxxxx> wrote: > > > From: Song Liu <songliubraving@xxxxxx> > > > > Enable specifying maxactive for fd based kretprobe. This will be useful > > for tracing tools like bcc and bpftrace (see for example discussion [1]). > > Use highest 12 bit (bit 52-63) to allow maximal maxactive of 4095. > > I'm not sure what environment you are considering to use this > feature, but is 4095 enough, and are you really need to specify > the maxactive by linear digit? > I mean you may need the logarithm of maxactive? In this case, you > only need 4 bits for 2 - 65546 (1 = 2^0 will be used for the default > value). >From what I see it's capped by KRETPROBE_MAXACTIVE_MAX anyway, which value is 4096. Do I miss something, is it possible to use maxactive with larger values down the line?
