/* * Controller of read/write threads for virtio-trace * * Copyright (C) 2012 Hitachi, Ltd. * Created by Yoshihiro Yunomae * Masami Hiramatsu * * Licensed under GPL version 2 only. * */ #define _GNU_SOURCE #include #include #include #include #include #include #include "trace-agent.h" #define HOST_MSG_SIZE 256 #define EVENT_WAIT_MSEC 100 static volatile sig_atomic_t global_signal_val; bool global_sig_receive; /* default false */ bool global_run_operation; /* default false*/ /* Handle SIGTERM/SIGINT/SIGQUIT to exit */ static void signal_handler(int sig) { global_signal_val = sig; } int rw_ctl_init(const char *ctl_path) { int ctl_fd; ctl_fd = open(ctl_path, O_RDONLY); if (ctl_fd == -1) { pr_err("Cannot open ctl_fd\n"); goto error; } return ctl_fd; error: exit(EXIT_FAILURE); } static int wait_order(int ctl_fd) { struct pollfd poll_fd; int ret = 0; while (!global_sig_receive) { poll_fd.fd = ctl_fd; poll_fd.events = POLLIN; ret = poll(&poll_fd, 1, EVENT_WAIT_MSEC); if (global_signal_val) { global_sig_receive = true; pr_info("Receive interrupt %d\n", global_signal_val); /* Wakes rw-threads when they are sleeping */ if (!global_run_operation) pthread_cond_broadcast(&cond_wakeup); ret = -1; break; } if (ret < 0) { pr_err("Polling error\n"); goto error; } if (ret) break; }; return ret; error: exit(EXIT_FAILURE); } /* * contol read/write threads by handling global_run_operation */ void *rw_ctl_loop(int ctl_fd) { ssize_t rlen; char buf[HOST_MSG_SIZE]; int ret; /* Setup signal handlers */ signal(SIGTERM, signal_handler); signal(SIGINT, signal_handler); signal(SIGQUIT, signal_handler); while (!global_sig_receive) { ret = wait_order(ctl_fd); if (ret < 0) break; rlen = read(ctl_fd, buf, sizeof(buf)); if (rlen < 0) { pr_err("read data error in ctl thread\n"); goto error; } if (rlen == 2 && buf[0] == '1') { /* * If host writes '1' to a control path, * this controller wakes all read/write threads. */ global_run_operation = true; pthread_cond_broadcast(&cond_wakeup); pr_debug("Wake up all read/write threads\n"); } else if (rlen == 2 && buf[0] == '0') { /* * If host writes '0' to a control path, read/write * threads will wait for notification from Host. */ global_run_operation = false; pr_debug("Stop all read/write threads\n"); } else pr_info("Invalid host notification: %s\n", buf); } return NULL; error: exit(EXIT_FAILURE); } b25'>root/include/net/netns
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authorThomas Gleixner <tglx@linutronix.de>2017-01-31 09:37:34 +0100
committerThomas Gleixner <tglx@linutronix.de>2017-01-31 21:47:58 +0100
commit0becc0ae5b42828785b589f686725ff5bc3b9b25 (patch)
treebe6d0e1f37c38ed0a7dd5da2d4b1e93f0fb43101 /include/net/netns
parent24c2503255d35c269b67162c397a1a1c1e02f6ce (diff)
x86/mce: Make timer handling more robust
Erik reported that on a preproduction hardware a CMCI storm triggers the BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is started by the CMCI logic before the MCE CPU hotplug callback starts the timer with add_timer_on(). So the timer is already queued which triggers the BUG. Using add_timer_on() is pretty pointless in this code because the timer is strictlty per CPU, initialized as pinned and all operations which arm the timer happen on the CPU to which the timer belongs. Simplify the whole machinery by using mod_timer() instead of add_timer_on() which avoids the problem because mod_timer() can handle already queued timers. Use __start_timer() everywhere so the earliest armed expiry time is preserved. Reported-by: Erik Veijola <erik.veijola@intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/net/netns')