From: David Gibson <david@gibson.dropbear.id.au>
To: Laurent Vivier <lvivier@redhat.com>
Cc: passt-dev@passt.top
Subject: Re: [PATCH 5/7] ctx: Remove epollfd from context structure
Date: Fri, 14 Aug 2026 16:34:25 +1000 [thread overview]
Message-ID: <an628JXz7ygnS8bI@zatzit> (raw)
In-Reply-To: <20260731164628.3556997-6-lvivier@redhat.com>
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On Fri, Jul 31, 2026 at 06:46:26PM +0200, Laurent Vivier wrote:
> The main epoll file descriptor is now managed by the threading subsystem,
> so there's no need to store it in the context structure.
> All code that previously accessed c->epollfd now calls
> threading_epollfd(THREADING_ID_DEFAULT) to get the main event loop's
> epoll file descriptor.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> conf.c | 10 +++++++---
> fwd.c | 4 +++-
> netlink.c | 4 +++-
> passt.c | 1 -
> passt.h | 2 --
> pasta.c | 3 ++-
> pif.c | 3 ++-
> repair.c | 12 ++++++++----
> tap.c | 9 ++++++---
> tcp_splice.c | 1 +
> vhost_user.c | 9 +++++----
> 11 files changed, 37 insertions(+), 21 deletions(-)
>
> diff --git a/conf.c b/conf.c
> index faf268140321..733bad4228cb 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -53,6 +53,7 @@
> #include "pesto.h"
> #include "serialise.h"
> #include "parse.h"
> +#include "threading.h"
>
> #define NETNS_RUN_DIR "/run/netns"
>
> @@ -1164,7 +1165,8 @@ static void conf_sock_listen(const struct ctx *c)
> die_perror("Couldn't listen on configuration socket");
>
> ref.fd = c->fd_control_listen;
> - if (epoll_add(c->epollfd, EPOLLIN | EPOLLET, ref))
> + if (epoll_add(threading_epollfd(THREADING_ID_DEFAULT),
> + EPOLLIN | EPOLLET, ref))
> die_perror("Couldn't add configuration socket to epoll");
> }
>
> @@ -2117,7 +2119,8 @@ static int conf_recv_rules(const struct ctx *c, int fd)
> static void conf_close(struct ctx *c)
> {
> debug("Closing configuration socket");
> - epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_control, NULL);
> + epoll_ctl(threading_epollfd(THREADING_ID_DEFAULT), EPOLL_CTL_DEL,
> + c->fd_control, NULL);
> close(c->fd_control);
> c->fd_control = -1;
> }
> @@ -2180,7 +2183,8 @@ retry:
> warn_perror("Can't get configuration client credentials");
>
> c->fd_control = ref.fd = fd;
> - rc = epoll_add(c->epollfd, EPOLLIN | EPOLLET, ref);
> + rc = epoll_add(threading_epollfd(THREADING_ID_DEFAULT),
> + EPOLLIN | EPOLLET, ref);
> if (rc < 0) {
> warn_perror("epoll_ctl() on configuration socket");
> goto fail;
> diff --git a/fwd.c b/fwd.c
> index 5679a3d606ea..fa6679ea1b2e 100644
> --- a/fwd.c
> +++ b/fwd.c
> @@ -33,6 +33,7 @@
> #include "netlink.h"
> #include "arp.h"
> #include "ndp.h"
> +#include "threading.h"
>
> #define NEIGH_TABLE_SLOTS 1024
> #define NEIGH_TABLE_SIZE (NEIGH_TABLE_SLOTS / 2)
> @@ -377,7 +378,8 @@ static int fwd_sync_one(const struct ctx *c, uint8_t pif, unsigned idx,
> /* We don't want to listen on this port */
> if (fd >= 0) {
> /* We already are, so stop */
> - epoll_del(c->epollfd, fd);
> + epoll_del(threading_epollfd(THREADING_ID_DEFAULT),
> + fd);
> close(fd);
> socks[port - rule->first] = -1;
> }
> diff --git a/netlink.c b/netlink.c
> index 8d20dbb57fb8..8fffe490b6f3 100644
> --- a/netlink.c
> +++ b/netlink.c
> @@ -37,6 +37,7 @@
> #include "ip.h"
> #include "netlink.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> /* Same as RTA_NEXT() but for nexthops: RTNH_NEXT() doesn't take 'attrlen' */
> #define RTNH_NEXT_AND_DEC(rtnh, attrlen) \
> @@ -1292,7 +1293,8 @@ int nl_neigh_notify_init(const struct ctx *c)
> }
>
> ev.data.u64 = ref.u64;
> - if (epoll_ctl(c->epollfd, EPOLL_CTL_ADD, nl_sock_neigh, &ev) == -1) {
> + if (epoll_ctl(threading_epollfd(THREADING_ID_DEFAULT), EPOLL_CTL_ADD,
> + nl_sock_neigh, &ev) == -1) {
> warn_perror("epoll_ctl() on neighbour notifier socket failed");
> close(nl_sock_neigh);
> nl_sock_neigh = -1;
> diff --git a/passt.c b/passt.c
> index 57290a5a7c6e..469e2525f545 100644
> --- a/passt.c
> +++ b/passt.c
> @@ -376,7 +376,6 @@ int main(int argc, char **argv)
> madvise(pkt_buf, sizeof(pkt_buf), MADV_HUGEPAGE);
>
> threading_init();
> - c->epollfd = threading_epollfd(THREADING_ID_DEFAULT);
>
> if (getrlimit(RLIMIT_NOFILE, &limit))
> die_perror("Failed to get maximum value of open files limit");
> diff --git a/passt.h b/passt.h
> index 00ef5a8f85e5..40abc5995ffd 100644
> --- a/passt.h
> +++ b/passt.h
> @@ -190,7 +190,6 @@ struct ip6_ctx {
> * @no_netns_quit: In pasta mode, don't exit if fs-bound namespace is gone
> * @netns_base: Base name for fs-bound namespace, if any, in pasta mode
> * @netns_dir: Directory of fs-bound namespace, if any, in pasta mode
> - * @epollfd: File descriptor for epoll instance
> * @fd_tap_listen: File descriptor for listening AF_UNIX socket, if any
> * @fd_tap: AF_UNIX socket, tuntap device, or pre-opened socket
> * @fd_control_listen: Listening control/configuration socket, if any
> @@ -266,7 +265,6 @@ struct ctx {
> char netns_base[PATH_MAX];
> char netns_dir[PATH_MAX];
>
> - int epollfd;
> int fd_tap_listen;
> int fd_tap;
> int fd_control_listen;
> diff --git a/pasta.c b/pasta.c
> index 5aa56b78d262..0a742a4f9abe 100644
> --- a/pasta.c
> +++ b/pasta.c
> @@ -50,6 +50,7 @@
> #include "netlink.h"
> #include "log.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> #define HOSTNAME_PREFIX "pasta-"
>
> @@ -517,7 +518,7 @@ void pasta_netns_quit_init(const struct ctx *c)
>
> ref.fd = fd;
>
> - epoll_add(c->epollfd, EPOLLIN, ref);
> + epoll_add(threading_epollfd(THREADING_ID_DEFAULT), EPOLLIN, ref);
> }
>
> /**
> diff --git a/pif.c b/pif.c
> index 8ade587c623a..e0a36413878b 100644
> --- a/pif.c
> +++ b/pif.c
> @@ -16,6 +16,7 @@
> #include "ip.h"
> #include "inany.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> const char pif_type_str[][PIF_NAME_SIZE] = {
> [PIF_NONE] = "<none>",
> @@ -130,7 +131,7 @@ int pif_listen(const struct ctx *c, uint8_t proto, uint8_t pif,
> goto fail;
> }
>
> - ret = epoll_add(c->epollfd, EPOLLIN, ref);
> + ret = epoll_add(threading_epollfd(THREADING_ID_DEFAULT), EPOLLIN, ref);
> if (ret < 0)
> goto fail;
>
> diff --git a/repair.c b/repair.c
> index f31ccceed7c6..7560242cf1c1 100644
> --- a/repair.c
> +++ b/repair.c
> @@ -23,6 +23,7 @@
> #include "flow.h"
> #include "flow_table.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> #include "repair.h"
>
> @@ -58,8 +59,9 @@ void repair_sock_init(const struct ctx *c)
> }
>
> ref.fd = c->fd_repair_listen;
> - if (epoll_add(c->epollfd, EPOLLIN | EPOLLHUP | EPOLLET, ref))
> - err("repair helper socket epoll_ctl(), won't migrate");
> + if (epoll_add(threading_epollfd(THREADING_ID_DEFAULT),
> + EPOLLIN | EPOLLHUP | EPOLLET, ref))
> + err_perror("repair helper socket epoll_ctl(), won't migrate");
> }
>
> /**
> @@ -115,7 +117,8 @@ int repair_listen_handler(struct ctx *c, uint32_t events)
>
> ref.fd = c->fd_repair;
>
> - rc = epoll_add(c->epollfd, EPOLLHUP | EPOLLET, ref);
> + rc = epoll_add(threading_epollfd(THREADING_ID_DEFAULT),
> + EPOLLHUP | EPOLLET, ref);
> if (rc < 0) {
> debug("epoll_ctl() on TCP_REPAIR helper socket");
> close(c->fd_repair);
> @@ -134,7 +137,8 @@ void repair_close(struct ctx *c)
> {
> debug("Closing TCP_REPAIR helper socket");
>
> - epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_repair, NULL);
> + epoll_ctl(threading_epollfd(THREADING_ID_DEFAULT), EPOLL_CTL_DEL,
> + c->fd_repair, NULL);
> close(c->fd_repair);
> c->fd_repair = -1;
> }
> diff --git a/tap.c b/tap.c
> index 25cde67538ac..d9be6bcc41a0 100644
> --- a/tap.c
> +++ b/tap.c
> @@ -61,6 +61,7 @@
> #include "vhost_user.h"
> #include "vu_common.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> /* Maximum allowed frame lengths (including L2 header) */
>
> @@ -1226,7 +1227,7 @@ void tap_sock_reset(struct ctx *c)
> passt_exit(EXIT_SUCCESS);
>
> /* Close the connected socket, wait for a new connection */
> - epoll_del(c->epollfd, c->fd_tap);
> + epoll_del(threading_epollfd(THREADING_ID_DEFAULT), c->fd_tap);
> close(c->fd_tap);
> c->fd_tap = -1;
> if (c->mode == MODE_VU)
> @@ -1417,7 +1418,8 @@ static void tap_sock_unix_init(const struct ctx *c)
>
> ref.fd = c->fd_tap_listen;
>
> - epoll_add(c->epollfd, EPOLLIN | EPOLLET, ref);
> + epoll_add(threading_epollfd(THREADING_ID_DEFAULT), EPOLLIN | EPOLLET,
> + ref);
> }
>
> /**
> @@ -1465,7 +1467,8 @@ static void tap_start_connection(const struct ctx *c)
> break;
> }
>
> - epoll_add(c->epollfd, EPOLLIN | EPOLLRDHUP, ref);
> + epoll_add(threading_epollfd(THREADING_ID_DEFAULT),
> + EPOLLIN | EPOLLRDHUP, ref);
>
> if (!tap_is_ready(c))
> return;
> diff --git a/tcp_splice.c b/tcp_splice.c
> index 8617e62cea9a..fc5b6c25670d 100644
> --- a/tcp_splice.c
> +++ b/tcp_splice.c
> @@ -56,6 +56,7 @@
> #include "inany.h"
> #include "flow.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> #include "flow_table.h"
>
> diff --git a/vhost_user.c b/vhost_user.c
> index 8ba3949e4e9d..ad316aee12c3 100644
> --- a/vhost_user.c
> +++ b/vhost_user.c
> @@ -44,6 +44,7 @@
> #include "pcap.h"
> #include "migrate.h"
> #include "epoll_ctl.h"
> +#include "threading.h"
>
> /* vhost-user version we are compatible with */
> #define VHOST_USER_VERSION 1
> @@ -736,7 +737,7 @@ static bool vu_get_vring_base_exec(struct vu_dev *vdev,
> vdev->vq[idx].call_fd = -1;
> }
> if (vdev->vq[idx].kick_fd != -1) {
> - epoll_del(vdev->context->epollfd, vdev->vq[idx].kick_fd);
> + epoll_del(threading_epollfd(THREADING_ID_DEFAULT), vdev->vq[idx].kick_fd);
> close(vdev->vq[idx].kick_fd);
> vdev->vq[idx].kick_fd = -1;
> }
> @@ -757,7 +758,7 @@ static void vu_set_watch(const struct vu_dev *vdev, int idx)
> .queue = idx
> };
>
> - epoll_add(vdev->context->epollfd, EPOLLIN, ref);
> + epoll_add(threading_epollfd(THREADING_ID_DEFAULT), EPOLLIN, ref);
> }
>
> /**
> @@ -802,7 +803,7 @@ static bool vu_set_vring_kick_exec(struct vu_dev *vdev,
> vu_check_queue_msg_file(vmsg);
>
> if (vdev->vq[idx].kick_fd != -1) {
> - epoll_del(vdev->context->epollfd, vdev->vq[idx].kick_fd);
> + epoll_del(threading_epollfd(THREADING_ID_DEFAULT), vdev->vq[idx].kick_fd);
> close(vdev->vq[idx].kick_fd);
> vdev->vq[idx].kick_fd = -1;
> }
> @@ -1095,7 +1096,7 @@ void vu_cleanup(struct vu_dev *vdev)
> vq->err_fd = -1;
> }
> if (vq->kick_fd != -1) {
> - epoll_del(vdev->context->epollfd, vq->kick_fd);
> + epoll_del(threading_epollfd(THREADING_ID_DEFAULT), vq->kick_fd);
> close(vq->kick_fd);
> vq->kick_fd = -1;
> }
> --
> 2.54.0
>
--
David Gibson (he or they) | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you, not the other way
| around.
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2026-08-14 6:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-31 16:46 [PATCH 0/7] multithreading: Add worker threads for queue pair processing Laurent Vivier
2026-07-31 16:46 ` [PATCH 1/7] vhost_user: Reset vq enable flag in vu_cleanup() Laurent Vivier
2026-08-12 4:15 ` David Gibson
2026-07-31 16:46 ` [PATCH 2/7] threading: Add basic threading infrastructure Laurent Vivier
2026-08-14 6:23 ` David Gibson
2026-07-31 16:46 ` [PATCH 3/7] passt: Integrate main event loop with " Laurent Vivier
2026-08-14 6:25 ` David Gibson
2026-07-31 16:46 ` [PATCH 4/7] flow: Delegate epoll file descriptor management to threading subsystem Laurent Vivier
2026-08-14 6:33 ` David Gibson
2026-07-31 16:46 ` [PATCH 5/7] ctx: Remove epollfd from context structure Laurent Vivier
2026-08-14 6:34 ` David Gibson [this message]
2026-07-31 16:46 ` [PATCH 6/7] vhost-user: Add per-qpair worker threads Laurent Vivier
2026-08-14 6:51 ` David Gibson
2026-07-31 16:46 ` [PATCH 7/7] virtio: Prevent crash on virtqueue exhaustion with temporary workaround Laurent Vivier
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