From patchwork Tue Aug 13 17:11:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier Langlois X-Patchwork-Id: 13762366 Received: from cloud48395.mywhc.ca (cloud48395.mywhc.ca [173.209.37.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2D501A01C5 for ; Tue, 13 Aug 2024 17:11:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.209.37.211 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723569079; cv=none; b=GPq5qDW3Vu9gBQFZRl/02BpHkGyHLJQ3VRlraduA3mXJcFcD7ZlOKMmCFs6s2KwCuladxMOIS1A8ha5gebuUdidQ9SiTrYsqOmb4tIuJI9rNZAOnwO5fkmoKLcNqWhYtaZ2FkC3xc9gZRuzynIZbsV/FvmpL0YWvptkTDzzs4gs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723569079; c=relaxed/simple; bh=7VlJ3hzXXkjKVOelB8jrZM6KiDBsAPTNOzsNv7kTZZM=; h=From:Date:Message-ID:In-Reply-To:References:To:Subject; b=Gi6eVbNtROyA9cMcN1xtC7VvAr3pufvKJ9XhXhcwi9Ar0pgM2H190LktZ+8PU1mDxxE07OaAditz13xg7XcHGSBTHlfkGzicWOhFR36UZMFCBUs5Am4TAVIj36vHBZSGBuDjBZCzxEG0yHTnyspmkqezukwC201lupCV7J7DS8Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=trillion01.com; spf=pass smtp.mailfrom=trillion01.com; arc=none smtp.client-ip=173.209.37.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=trillion01.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=trillion01.com Received: from [45.44.224.220] (port=48534 helo=localhost) by cloud48395.mywhc.ca with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96.2) (envelope-from ) id 1sdv3D-0003JO-14; Tue, 13 Aug 2024 13:11:15 -0400 From: Olivier Langlois Date: Tue, 13 Aug 2024 13:11:14 -0400 Message-ID: <5fc9dd07e48a7178f547ed1b2aaa0814607fa246.1723567469.git.olivier@trillion01.com> In-Reply-To: References: To: Jens Axboe ,Pavel Begunkov ,io-uring@vger.kernel.org Subject: [PATCH 2/2] io_uring/napi: add static napi tracking strategy X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cloud48395.mywhc.ca X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - trillion01.com X-Get-Message-Sender-Via: cloud48395.mywhc.ca: authenticated_id: olivier@trillion01.com X-Authenticated-Sender: cloud48395.mywhc.ca: olivier@trillion01.com X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: add the static napi tracking strategy that allows the user to manually manage the napi ids list to busy poll and offload the ring from dynamically update the list. Signed-off-by: Olivier Langlois --- include/uapi/linux/io_uring.h | 30 ++++++- io_uring/napi.c | 162 ++++++++++++++++++++++++++++------ 2 files changed, 163 insertions(+), 29 deletions(-) diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 2aaf7ee256ac..f72471b19af2 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -728,12 +728,38 @@ struct io_uring_buf_status { __u32 resv[8]; }; +enum io_uring_napi_op { + /* register/ungister backward compatible opcode */ + IO_URING_NAPI_REGISTER_OP = 0, + + /* opcodes to update napi_list when static tracking is used */ + IO_URING_NAPI_STATIC_ADD_ID = 1, + IO_URING_NAPI_STATIC_DEL_ID = 2 +}; + +enum io_uring_napi_tracking_strategy { + IO_URING_NAPI_TRACKING_DYNAMIC = 0, + IO_URING_NAPI_TRACKING_STATIC = 1 +}; + /* argument for IORING_(UN)REGISTER_NAPI */ struct io_uring_napi { __u32 busy_poll_to; __u8 prefer_busy_poll; - __u8 pad[3]; - __u64 resv; + + /* a io_uring_napi_op value */ + __u8 opcode; + __u8 pad[2]; + + /* + * for IO_URING_NAPI_REGISTER_OP, it is a + * io_uring_napi_tracking_strategy value. + * + * for IO_URING_NAPI_STATIC_ADD_ID/IO_URING_NAPI_STATIC_DEL_ID + * it is the napi id to add/del from napi_list. + */ + __u32 op_param; + __u32 resv; }; /* diff --git a/io_uring/napi.c b/io_uring/napi.c index 75ac850af0c0..b66ff15fcc72 100644 --- a/io_uring/napi.c +++ b/io_uring/napi.c @@ -38,37 +38,29 @@ static inline ktime_t net_to_ktime(unsigned long t) return ns_to_ktime(t << 10); } -static inline void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock) +static int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id) { struct hlist_head *hash_list; - unsigned int napi_id; - struct sock *sk; struct io_napi_entry *e; - sk = sock->sk; - if (!sk) - return; - - napi_id = READ_ONCE(sk->sk_napi_id); - /* Non-NAPI IDs can be rejected. */ if (napi_id < MIN_NAPI_ID) - return; + return -EINVAL; hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; rcu_read_lock(); e = io_napi_hash_find(hash_list, napi_id); if (e) { - e->timeout = jiffies + NAPI_TIMEOUT; + WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT); rcu_read_unlock(); - return; + return -EEXIST; } rcu_read_unlock(); e = kmalloc(sizeof(*e), GFP_NOWAIT); if (!e) - return; + return -ENOMEM; e->napi_id = napi_id; e->timeout = jiffies + NAPI_TIMEOUT; @@ -77,23 +69,62 @@ static inline void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock) if (unlikely(io_napi_hash_find(hash_list, napi_id))) { spin_unlock(&ctx->napi_lock); kfree(e); - return; + return -EEXIST; } hlist_add_tail_rcu(&e->node, hash_list); - list_add_tail(&e->list, &ctx->napi_list); + list_add_tail_rcu(&e->list, &ctx->napi_list); spin_unlock(&ctx->napi_lock); + return 0; +} + +static int __io_napi_del_id(struct io_ring_ctx *ctx, unsigned int napi_id) +{ + struct hlist_head *hash_list; + struct io_napi_entry *e; + + /* Non-NAPI IDs can be rejected. */ + if (napi_id < MIN_NAPI_ID) + return -EINVAL; + + hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; + spin_lock(&ctx->napi_lock); + e = io_napi_hash_find(hash_list, napi_id); + if (unlikely(!e)) { + spin_unlock(&ctx->napi_lock); + return -ENOENT; + } + + list_del_rcu(&e->list); + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + spin_unlock(&ctx->napi_lock); + return 0; +} + +static inline void __io_napi_add(struct io_ring_ctx *ctx, struct socket *sock) +{ + unsigned int napi_id; + struct sock *sk; + + sk = sock->sk; + if (!sk) + return; + + napi_id = READ_ONCE(sk->sk_napi_id); + __io_napi_add_id(ctx, napi_id); } static void __io_napi_remove_stale(struct io_ring_ctx *ctx) { + struct hlist_node *tmp; struct io_napi_entry *e; unsigned int i; spin_lock(&ctx->napi_lock); - hash_for_each(ctx->napi_ht, i, e, node) { + hash_for_each_safe(ctx->napi_ht, i, tmp, e, node) { if (time_after(jiffies, e->timeout)) { - list_del(&e->list); + list_del_rcu(&e->list); hash_del_rcu(&e->node); kfree_rcu(e, rcu); } @@ -201,23 +232,68 @@ static bool dynamic_tracking_do_busy_loop(struct io_ring_ctx *ctx, return is_stale; } -static void dynamic_tracking_show_fdinfo(struct io_ring_ctx *ctx, - struct seq_file *m) +static void common_tracking_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m, + const char *tracking_strategy) { seq_puts(m, "NAPI:\tenabled\n"); - seq_printf(m, "napi_busy_poll_to:\t%u\n", ctx->napi_busy_poll_to); + seq_printf(m, "napi tracking:\t%s\n", tracking_strategy); + seq_printf(m, "napi_busy_poll_to:\t%llu\n", ctx->napi_busy_poll_dt); if (ctx->napi_prefer_busy_poll) seq_puts(m, "napi_prefer_busy_poll:\ttrue\n"); else seq_puts(m, "napi_prefer_busy_poll:\tfalse\n"); } +static void dynamic_tracking_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m) +{ + common_tracking_show_fdinfo(ctx, m, "dynamic"); +} + static struct io_napi_tracking_ops dynamic_tracking_ops = { .add_id = dynamic_tracking_add_id, .do_busy_loop = dynamic_tracking_do_busy_loop, - .show_fdinfo = dynamic_tracking_show_fdinfo, + .show_fdinfo = dynamic_tracking_show_fdinfo, +}; + +/* + * never report stale entries + */ +static bool static_tracking_do_busy_loop(struct io_ring_ctx *ctx, + void *loop_end_arg) +{ + struct io_napi_entry *e; + bool (*loop_end)(void *, unsigned long) = NULL; + + if (loop_end_arg) + loop_end = io_napi_busy_loop_should_end; + + list_for_each_entry_rcu(e, &ctx->napi_list, list) { + napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, + ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); + } + + return false; +} + +static void static_tracking_show_fdinfo(struct io_ring_ctx *ctx, + struct seq_file *m) +{ + common_tracking_show_fdinfo(ctx, m, "static"); +} + +static struct io_napi_tracking_ops static_tracking_ops = { + .add_id = NULL, + .do_busy_loop = static_tracking_do_busy_loop, + .show_fdinfo = static_tracking_show_fdinfo, }; +static inline u32 io_napi_get_tracking(struct io_ring_ctx *ctx) +{ + return ctx->napi_ops == &static_tracking_ops; +} + static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) { @@ -273,9 +349,30 @@ void io_napi_free(struct io_ring_ctx *ctx) hash_del_rcu(&e->node); kfree_rcu(e, rcu); } + INIT_LIST_HEAD_RCU(&ctx->napi_list); spin_unlock(&ctx->napi_lock); } +static int io_napi_register_napi(struct io_ring_ctx *ctx, + struct io_uring_napi *napi) +{ + switch (napi->op_param) { + case IO_URING_NAPI_TRACKING_DYNAMIC: + WRITE_ONCE(ctx->napi_ops, &dynamic_tracking_ops); + break; + case IO_URING_NAPI_TRACKING_STATIC: + WRITE_ONCE(ctx->napi_ops, &static_tracking_ops); + /* clean the napi list for manual setup */ + io_napi_free(ctx); + break; + default: + return -EINVAL; + } + WRITE_ONCE(ctx->napi_busy_poll_dt, napi->busy_poll_to * NSEC_PER_USEC); + WRITE_ONCE(ctx->napi_prefer_busy_poll, !!napi->prefer_busy_poll); + return 0; +} + /* * io_napi_register() - Register napi with io-uring * @ctx: pointer to io-uring context structure @@ -287,7 +384,8 @@ int io_register_napi(struct io_ring_ctx *ctx, void __user *arg) { const struct io_uring_napi curr = { .busy_poll_to = ktime_to_us(ctx->napi_busy_poll_dt), - .prefer_busy_poll = ctx->napi_prefer_busy_poll + .prefer_busy_poll = ctx->napi_prefer_busy_poll, + .op_param = io_napi_get_tracking(ctx) }; struct io_uring_napi napi; @@ -295,16 +393,26 @@ int io_register_napi(struct io_ring_ctx *ctx, void __user *arg) return -EINVAL; if (copy_from_user(&napi, arg, sizeof(napi))) return -EFAULT; - if (napi.pad[0] || napi.pad[1] || napi.pad[2] || napi.resv) + if (napi.pad[0] || napi.pad[1] || napi.resv) return -EINVAL; if (copy_to_user(arg, &curr, sizeof(curr))) return -EFAULT; - WRITE_ONCE(ctx->napi_busy_poll_dt, napi.busy_poll_to * NSEC_PER_USEC); - WRITE_ONCE(ctx->napi_prefer_busy_poll, !!napi.prefer_busy_poll); - WRITE_ONCE(ctx->napi_ops, &dynamic_tracking_ops); - return 0; + switch (napi.opcode) { + case IO_URING_NAPI_REGISTER_OP: + return io_napi_register_napi(ctx, &napi); + case IO_URING_NAPI_STATIC_ADD_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_add_id(ctx, napi.op_param); + case IO_URING_NAPI_STATIC_DEL_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_del_id(ctx, napi.op_param); + default: + return -EINVAL; + } } /*