/* * LAPB release 002 * * This code REQUIRES 2.1.15 or higher/ NET3.038 * * This module: * This module is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * History * LAPB 001 Jonathan Naylor Started Coding * LAPB 002 Jonathan Naylor New timer architecture. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * This procedure is passed a buffer descriptor for an iframe. It builds * the rest of the control part of the frame and then writes it out. */ static void lapb_send_iframe(struct lapb_cb *lapb, struct sk_buff *skb, int poll_bit) { unsigned char *frame; if (!skb) return; if (lapb->mode & LAPB_EXTENDED) { frame = skb_push(skb, 2); frame[0] = LAPB_I; frame[0] |= lapb->vs << 1; frame[1] = poll_bit ? LAPB_EPF : 0; frame[1] |= lapb->vr << 1; } else { frame = skb_push(skb, 1); *frame = LAPB_I; *frame |= poll_bit ? LAPB_SPF : 0; *frame |= lapb->vr << 5; *frame |= lapb->vs << 1; } lapb_dbg(1, "(%p) S%d TX I(%d) S%d R%d\n", lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr); lapb_transmit_buffer(lapb, skb, LAPB_COMMAND); } void lapb_kick(struct lapb_cb *lapb) { struct sk_buff *skb, *skbn; unsigned short modulus, start, end; modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS; start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs; end = (lapb->va + lapb->window) % modulus; if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) && start != end && skb_peek(&lapb->write_queue)) { lapb->vs = start; /* * Dequeue the frame and copy it. */ skb = skb_dequeue(&lapb->write_queue); do { if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { skb_queue_head(&lapb->write_queue, skb); break; } if (skb->sk) skb_set_owner_w(skbn, skb->sk); /* * Transmit the frame copy. */ lapb_send_iframe(lapb, skbn, LAPB_POLLOFF); lapb->vs = (lapb->vs + 1) % modulus; /* * Requeue the original data frame. */ skb_queue_tail(&lapb->ack_queue, skb); } while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL); lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; if (!lapb_t1timer_running(lapb)) lapb_start_t1timer(lapb); } } void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type) { unsigned char *ptr; ptr = skb_push(skb, 1); if (lapb->mode & LAPB_MLP) { if (lapb->mode & LAPB_DCE) { if (type == LAPB_COMMAND) *ptr = LAPB_ADDR_C; if (type == LAPB_RESPONSE) *ptr = LAPB_ADDR_D; } else { if (type == LAPB_COMMAND) *ptr = LAPB_ADDR_D; if (type == LAPB_RESPONSE) *ptr = LAPB_ADDR_C; } } else { if (lapb->mode & LAPB_DCE) { if (type == LAPB_COMMAND) *ptr = LAPB_ADDR_A; if (type == LAPB_RESPONSE) *ptr = LAPB_ADDR_B; } else { if (type == LAPB_COMMAND) *ptr = LAPB_ADDR_B; if (type == LAPB_RESPONSE) *ptr = LAPB_ADDR_A; } } lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data); if (!lapb_data_transmit(lapb, skb)) kfree_skb(skb); } void lapb_establish_data_link(struct lapb_cb *lapb) { lapb->condition = 0x00; lapb->n2count = 0; if (lapb->mode & LAPB_EXTENDED) { lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state); lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND); } else { lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state); lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND); } lapb_start_t1timer(lapb); lapb_stop_t2timer(lapb); } void lapb_enquiry_response(struct lapb_cb *lapb) { lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n", lapb->dev, lapb->state, lapb->vr); lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE); lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; } void lapb_timeout_response(struct lapb_cb *lapb) { lapb_dbg(1, "(%p) S%d TX RR(0) R%d\n", lapb->dev, lapb->state, lapb->vr); lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE); lapb->condition &= ~LAPB_ACK_PENDING_CONDITION; } void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr) { if (lapb->vs == nr) { lapb_frames_acked(lapb, nr); lapb_stop_t1timer(lapb); lapb->n2count = 0; } else if (lapb->va != nr) { lapb_frames_acked(lapb, nr); lapb_start_t1timer(lapb); } } void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf) { if (type == LAPB_COMMAND && pf) lapb_enquiry_response(lapb); } ux/net-next.git/patch/include?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>patch) tree370efda701f03cccf21e02bb1fdd3b852547d75c /include parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include')