Date: Thu, 6 Nov 2025 00:00:43 GMT From: Andrew Gallatin <gallatin@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 9349214a2815 - main - mlx5: Preallocate ktls tags asynchronously Message-ID: <202511060000.5A600hbJ087505@gitrepo.freebsd.org>
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The branch main has been updated by gallatin: URL: https://cgit.FreeBSD.org/src/commit/?id=9349214a28152a3cb2424459976f571a9c8fc5df commit 9349214a28152a3cb2424459976f571a9c8fc5df Author: Andrew Gallatin <gallatin@FreeBSD.org> AuthorDate: 2025-11-05 23:58:33 +0000 Commit: Andrew Gallatin <gallatin@FreeBSD.org> CommitDate: 2025-11-05 23:58:33 +0000 mlx5: Preallocate ktls tags asynchronously Change tag preallocation to happen asynchronously when an interface is brought up, so as to reduce boot times when preallocating tags. - A new mlx5-tls-prealloc_wq is allocated when preallocation is desired, and started when an interface is opened - The bulk of the prealloc code remains the same, except the allocations are now M_NOWAIT. M_NOWAIT is needed because, since the preallocation is done asynchronously, and since tag allocation is not instant, we could race with a real TLS session trying to allocate a tag. Note that in this case, we take allocation failure as a sign that we were unable to obtain the entire zone due to there being other consumers. This was suggested by @markj as a way to keep things simple, after discussing why uma_zone_get_cur() didn't immediately report a fully allocated zone. If this turns out to be problematic, we could use uma_zone_set_maxaction() to stop pre-allocations (also suggested by Mark) Reviewed by: glebius, kib, markj Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D53570 --- sys/dev/mlx5/mlx5_en/en_hw_tls.h | 3 ++ sys/dev/mlx5/mlx5_en/mlx5_en_hw_tls.c | 53 +++++++++++++++++++++++++++++------ sys/dev/mlx5/mlx5_en/mlx5_en_main.c | 3 ++ 3 files changed, 50 insertions(+), 9 deletions(-) diff --git a/sys/dev/mlx5/mlx5_en/en_hw_tls.h b/sys/dev/mlx5/mlx5_en/en_hw_tls.h index d637314e040e..cd57d2ac5f72 100644 --- a/sys/dev/mlx5/mlx5_en/en_hw_tls.h +++ b/sys/dev/mlx5/mlx5_en/en_hw_tls.h @@ -82,6 +82,8 @@ struct mlx5e_tls { struct sysctl_ctx_list ctx; struct mlx5e_tls_stats stats; struct workqueue_struct *wq; + struct workqueue_struct *prealloc_wq; + struct work_struct prealloc_work; uma_zone_t zone; uint32_t max_resources; /* max number of resources */ int zone_max; @@ -92,6 +94,7 @@ struct mlx5e_tls { int mlx5e_tls_init(struct mlx5e_priv *); void mlx5e_tls_cleanup(struct mlx5e_priv *); int mlx5e_sq_tls_xmit(struct mlx5e_sq *, struct mlx5e_xmit_args *, struct mbuf **); +void mlx5e_tls_prealloc_tags(struct mlx5e_priv *priv); if_snd_tag_alloc_t mlx5e_tls_snd_tag_alloc; diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_hw_tls.c b/sys/dev/mlx5/mlx5_en/mlx5_en_hw_tls.c index 6c83de5f3580..851316ccfcd7 100644 --- a/sys/dev/mlx5/mlx5_en/mlx5_en_hw_tls.c +++ b/sys/dev/mlx5/mlx5_en/mlx5_en_hw_tls.c @@ -80,23 +80,39 @@ static const char *mlx5e_tls_stats_desc[] = { }; static void mlx5e_tls_work(struct work_struct *); +static void mlx5e_tls_prealloc_work(struct work_struct *); /* - * Expand the tls tag UMA zone in a sleepable context + * Expand the tls tag UMA zone in an async context */ static void -mlx5e_prealloc_tags(struct mlx5e_priv *priv, int nitems) +mlx5e_tls_prealloc_work(struct work_struct *work) { + struct mlx5e_priv *priv; + struct mlx5e_tls *ptls; struct mlx5e_tls_tag **tags; - int i; + int i, nitems; + + ptls = container_of(work, struct mlx5e_tls, prealloc_work); + priv = container_of(ptls, struct mlx5e_priv, tls); + nitems = ptls->zone_max; tags = malloc(sizeof(tags[0]) * nitems, - M_MLX5E_TLS, M_WAITOK); - for (i = 0; i < nitems; i++) - tags[i] = uma_zalloc(priv->tls.zone, M_WAITOK); + M_MLX5E_TLS, M_WAITOK | M_ZERO); + for (i = 0; i < nitems; i++) { + tags[i] = uma_zalloc(priv->tls.zone, M_NOWAIT); + /* + * If the allocation fails, its likely we are competing + * with real consumers of tags and the zone is full, + * so exit the loop, and release the tags like we would + * if we allocated all "nitems" + */ + if (tags[i] == NULL) + break; + } __compiler_membar(); - for (i = 0; i < nitems; i++) + for (i = 0; i < nitems && tags[i] != NULL; i++) uma_zfree(priv->tls.zone, tags[i]); free(tags, M_MLX5E_TLS); } @@ -244,8 +260,6 @@ mlx5e_tls_init(struct mlx5e_priv *priv) } uma_zone_set_max(ptls->zone, ptls->zone_max); - if (prealloc_tags != 0) - mlx5e_prealloc_tags(priv, ptls->zone_max); for (x = 0; x != MLX5E_TLS_STATS_NUM; x++) ptls->stats.arg[x] = counter_u64_alloc(M_WAITOK); @@ -270,6 +284,23 @@ mlx5e_tls_init(struct mlx5e_priv *priv) return (0); } +void +mlx5e_tls_prealloc_tags(struct mlx5e_priv *priv) +{ + struct mlx5e_tls *ptls = &priv->tls; + int prealloc_tags = 0; + + if (ptls->prealloc_wq != NULL) + return; + + TUNABLE_INT_FETCH("hw.mlx5.tls_prealloc_tags", &prealloc_tags); + if (prealloc_tags == 0) + return; + ptls->prealloc_wq = create_singlethread_workqueue("mlx5-tls-prealloc_wq"); + INIT_WORK(&ptls->prealloc_work, mlx5e_tls_prealloc_work); + queue_work(ptls->prealloc_wq, &ptls->prealloc_work); +} + void mlx5e_tls_cleanup(struct mlx5e_priv *priv) { @@ -280,6 +311,10 @@ mlx5e_tls_cleanup(struct mlx5e_priv *priv) return; ptls->init = 0; + if (ptls->prealloc_wq != NULL) { + flush_workqueue(ptls->prealloc_wq); + destroy_workqueue(ptls->prealloc_wq); + } flush_workqueue(ptls->wq); sysctl_ctx_free(&ptls->ctx); uma_zdestroy(ptls->zone); diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c index f83506bda1aa..ee9c53bb0a60 100644 --- a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c +++ b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c @@ -3335,6 +3335,9 @@ mlx5e_open_locked(if_t ifp) mlx5e_update_carrier(priv); + if ((if_getcapenable(ifp) & (IFCAP_TXTLS4 | IFCAP_TXTLS6)) != 0) + mlx5e_tls_prealloc_tags(priv); + return (0); err_close_channels:help
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