seastar-separate-accept.patch

--- a/include/seastar/core/internal/pollable_fd.hh
+++ b/include/seastar/core/internal/pollable_fd.hh
@@ -57,6 +57,7 @@ class pollable_fd_state {
     int events_requested = 0; // wanted by pollin/pollout promises
     int events_epoll = 0;     // installed in epoll
     int events_known = 0;     // returned from epoll
+    bool is_acceptor = false; // put acceptor to disinct epoll
     promise<> pollin;
     promise<> pollout;
     friend class reactor;
diff --git a/src/core/reactor.cc b/src/core/reactor.cc
index f57ca0c9..83acfbce 100644
--- a/src/core/reactor.cc
+++ b/src/core/reactor.cc
@@ -667,6 +667,8 @@ class reactor_backend_epoll : public reactor_backend {
     bool _timer_enabled = false;
 private:
     file_desc _epollfd;
+    file_desc _epollfd_for_acceptor;
+    file_desc& get_epollfd(pollable_fd_state& fd);
     future<> get_epoll_future(pollable_fd_state& fd,
             promise<> pollable_fd_state::* pr, int event);
     void complete_epoll_event(pollable_fd_state& fd,
@@ -978,8 +980,10 @@ class reactor_backend_aio : public reactor_backend {
     }
 };
 
-reactor_backend_epoll::reactor_backend_epoll(reactor* r)
-        : _r(r), _epollfd(file_desc::epoll_create(EPOLL_CLOEXEC)) {
+reactor_backend_epoll::reactor_backend_epoll(reactor* r) :
+    _r(r),
+    _epollfd(file_desc::epoll_create(EPOLL_CLOEXEC)),
+    _epollfd_for_acceptor(file_desc::epoll_create(EPOLL_CLOEXEC)) {
     ::epoll_event event;
     event.events = EPOLLIN;
     event.data.ptr = nullptr;
@@ -1800,6 +1804,13 @@ void reactor::configure(boost::program_options::variables_map vm) {
     aio_nowait_supported = vm["linux-aio-nowait"].as<bool>();
 }
 
+file_desc& reactor_backend_epoll::get_epollfd(pollable_fd_state& fd) {
+    if (fd.is_acceptor) {
+        return _epollfd_for_acceptor;
+    }
+    return _epollfd;
+}
+
 future<> reactor_backend_epoll::get_epoll_future(pollable_fd_state& pfd,
         promise<> pollable_fd_state::*pr, int event) {
     if (pfd.events_known & event) {
@@ -1814,7 +1825,7 @@ future<> reactor_backend_epoll::get_epoll_future(pollable_fd_state& pfd,
         ::epoll_event eevt;
         eevt.events = pfd.events_epoll;
         eevt.data.ptr = &pfd;
-        int r = ::epoll_ctl(_epollfd.get(), ctl, pfd.fd.get(), &eevt);
+        int r = ::epoll_ctl(get_epollfd(pfd).get(), ctl, pfd.fd.get(), &eevt);
         assert(r == 0);
         engine().start_epoll();
     }
@@ -1836,7 +1847,7 @@ future<> reactor_backend_epoll::readable_or_writeable(pollable_fd_state& fd) {
 
 void reactor_backend_epoll::forget(pollable_fd_state& fd) {
     if (fd.events_epoll) {
-        ::epoll_ctl(_epollfd.get(), EPOLL_CTL_DEL, fd.fd.get(), nullptr);
+        ::epoll_ctl(get_epollfd(fd).get(), EPOLL_CTL_DEL, fd.fd.get(), nullptr);
     }
 }
 
@@ -1856,7 +1867,9 @@ reactor::posix_listen(socket_address sa, listen_options opts) {
         throw std::system_error(s.code(), fmt::format("posix_listen failed for address {}", sa));
     }
 
-    return pollable_fd(std::move(fd));
+    pollable_fd pfd(std::move(fd));
+    pfd._s->is_acceptor = true;
+    return pfd;
 }
 
 bool
@@ -4518,8 +4531,23 @@ reactor::poller::~poller() {
 bool
 reactor_backend_epoll::wait_and_process(int timeout, const sigset_t* active_sigmask) {
     thread_local static std::chrono::steady_clock::time_point last_epoll_flushed = std::chrono::steady_clock::now();
+    thread_local std::size_t count = 0;
     std::array<epoll_event, 128> eevt;
-    int nr = ::epoll_pwait(_epollfd.get(), eevt.data(), eevt.size(), timeout, active_sigmask);
+    file_desc* epoll_fd_ptr;
+    int timeout_val;
+    if (++count % 2 == 0) {
+        epoll_fd_ptr = &_epollfd_for_acceptor;
+        timeout_val = 0;
+    } else {
+        epoll_fd_ptr = &_epollfd;
+        timeout_val = timeout;
+    }
+    int nr = ::epoll_pwait(epoll_fd_ptr->get(), eevt.data(), eevt.size(), timeout_val, active_sigmask);
+    if (nr == 0 && epoll_fd_ptr == &_epollfd_for_acceptor) {
+        epoll_fd_ptr = &_epollfd;
+        timeout_val = timeout;
+        nr = ::epoll_pwait(epoll_fd_ptr->get(), eevt.data(), eevt.size(), timeout_val, active_sigmask);
+    }
     if (nr == -1 && errno == EINTR) {
         return false; // gdb can cause this
     }
@@ -4557,7 +4585,7 @@ reactor_backend_epoll::wait_and_process(int timeout, const sigset_t* active_sigm
             pfd->events_epoll &= ~events_to_remove;
             evt.events = pfd->events_epoll;
             auto op = evt.events ? EPOLL_CTL_MOD : EPOLL_CTL_DEL;
-            ::epoll_ctl(_epollfd.get(), op, pfd->fd.get(), &evt);
+            ::epoll_ctl(epoll_fd_ptr->get(), op, pfd->fd.get(), &evt);
         }
     }
     return nr;