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. Thank you, -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
