> On Sun, Jun 12, 2022 at 09:12:32PM +0900, Masami Hiramatsu wrote: > On Sat, 11 Jun 2022 11:28:36 -0700 > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > > On Thu, Jun 9, 2022 at 1:14 PM Dmitry Dolgov <9erthalion6@xxxxxxxxx> wrote: > > > > > > > On Thu, Jun 09, 2022 at 09:29:36PM +0200, Dmitrii Dolgov wrote: > > > > > > > > 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. > > > > > > > > The original patch [2] seems to be fallen through the cracks and wasn't > > > > applied. I've merely rebased the work done by Song Liu and verififed it > > > > still works. > > > > > > > > [1]: https://github.com/iovisor/bpftrace/issues/835 > > > > [2]: https://lore.kernel.org/all/20191007223111.1142454-1-songliubraving@xxxxxx/ > > > > > > I've recently stumbled upon this seemingly lost topic, and wanted to raise it > > > again. Please let me know if there is a more appropriate way to do so. > > > > With kretprobe using rethook the maxactive limit is no longer used. > > So we probably don't need this patch. > > > > Masami, wdyt? > > No, rethook is just a library version of kretprobe return hook, > so the maxactive is still alive. I would like to make the rethook > to use(share with) function graph's per-task shadow stack. When > that is done, the maxactive will be removed. Thanks for clarification! Does it mean that the possibility of setting maxactive still makes sense, until the rethook changes you've mentioned will land? On a side note, is it possible to somehow follow/review/test the work about rethook and function graph's shadow stack?
