From: Florin Coras <fcoras@cisco.com>
Date: Thu, 31 Oct 2024 07:55:04 +0000 (-0700)
Subject: vcl: make ldp workers thread local
X-Git-Tag: v25.06-rc0~140
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F98%2F41798%2F7;p=vpp.git

vcl: make ldp workers thread local

Multi-threaded apps that do not allocate per-thread workers
(multi-thread workers vcl config) ended up sharing worker state like the
select bitmaps and time among others. Those should not be shared.

To avoid this, make ldp workers thread local variables.

Type: fix

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Iabdcc413991dbaafff33f24187f7053a9c5a1270
---

diff --git a/src/vcl/ldp.c b/src/vcl/ldp.c
index 4510bf85e1b..befb30851cd 100644
--- a/src/vcl/ldp.c
+++ b/src/vcl/ldp.c
@@ -105,6 +105,8 @@ typedef struct ldp_worker_ctx_
   int vcl_mq_epfd;
 } ldp_worker_ctx_t;
 
+__thread ldp_worker_ctx_t _ldp_worker = {};
+
 /* clib_bitmap_t, fd_mask and vcl_si_set are used interchangeably. Make sure
  * they are the same size */
 STATIC_ASSERT (sizeof (clib_bitmap_t) == sizeof (fd_mask),
@@ -114,7 +116,6 @@ STATIC_ASSERT (sizeof (vcl_si_set) == sizeof (fd_mask),
 
 typedef struct
 {
-  ldp_worker_ctx_t *workers;
   int init;
   char app_name[LDP_APP_NAME_MAX];
   u32 vlsh_bit_val;
@@ -154,7 +155,7 @@ static ldp_main_t *ldp = &ldp_main;
 static inline ldp_worker_ctx_t *
 ldp_worker_get_current (void)
 {
-  return (ldp->workers + vppcom_worker_index ());
+  return &_ldp_worker;
 }
 
 /*
@@ -190,14 +191,6 @@ ldp_fd_to_vlsh (int fd)
   return (fd - ldp->vlsh_bit_val);
 }
 
-static void
-ldp_alloc_workers (void)
-{
-  if (ldp->workers)
-    return;
-  ldp->workers = vec_new (ldp_worker_ctx_t, LDP_MAX_NWORKERS);
-}
-
 static void
 ldp_init_cfg (void)
 {
@@ -285,7 +278,6 @@ ldp_init_cfg (void)
 static int
 ldp_init (void)
 {
-  ldp_worker_ctx_t *ldpw;
   int rv;
 
   if (ldp->init)
@@ -311,10 +303,6 @@ ldp_init (void)
       return rv;
     }
   ldp->vcl_needs_real_epoll = 0;
-  ldp_alloc_workers ();
-
-  vec_foreach (ldpw, ldp->workers)
-    clib_memset (&ldpw->clib_time, 0, sizeof (ldpw->clib_time));
 
   LDBG (0, "LDP initialization: done!");
 
@@ -2397,14 +2385,9 @@ epoll_create1 (int flags)
 
   if (ldp->vcl_needs_real_epoll || vls_use_real_epoll ())
     {
-      /* Make sure workers have been allocated */
-      if (!ldp->workers)
-	{
-	  ldp_alloc_workers ();
-	  ldpw = ldp_worker_get_current ();
-	}
       rv = libc_epoll_create1 (flags);
       ldp->vcl_needs_real_epoll = 0;
+      /* Assume this is a request to create the mq epfd */
       ldpw->vcl_mq_epfd = rv;
       LDBG (0, "created vcl epfd %u", rv);
       return rv;
@@ -2665,6 +2648,7 @@ ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
   if (PREDICT_FALSE (!ldpw->mq_epfd_added))
     {
       struct epoll_event e = { 0 };
+      ldpw->vcl_mq_epfd = vppcom_mq_epoll_fd ();
       e.events = EPOLLIN;
       e.data.fd = ldpw->vcl_mq_epfd;
       if (libc_epoll_ctl (libc_epfd, EPOLL_CTL_ADD, ldpw->vcl_mq_epfd, &e) <