/* * TCP HYBLA * * TCP-HYBLA Congestion control algorithm, based on: * C.Caini, R.Firrincieli, "TCP-Hybla: A TCP Enhancement * for Heterogeneous Networks", * International Journal on satellite Communications, * September 2004 * Daniele Lacamera * root at danielinux.net */ #include #include /* Tcp Hybla structure. */ struct hybla { bool hybla_en; u32 snd_cwnd_cents; /* Keeps increment values when it is <1, <<7 */ u32 rho; /* Rho parameter, integer part */ u32 rho2; /* Rho * Rho, integer part */ u32 rho_3ls; /* Rho parameter, <<3 */ u32 rho2_7ls; /* Rho^2, <<7 */ u32 minrtt_us; /* Minimum smoothed round trip time value seen */ }; /* Hybla reference round trip time (default= 1/40 sec = 25 ms), in ms */ static int rtt0 = 25; module_param(rtt0, int, 0644); MODULE_PARM_DESC(rtt0, "reference rout trip time (ms)"); /* This is called to refresh values for hybla parameters */ static inline void hybla_recalc_param (struct sock *sk) { struct hybla *ca = inet_csk_ca(sk); ca->rho_3ls = max_t(u32, tcp_sk(sk)->srtt_us / (rtt0 * USEC_PER_MSEC), 8U); ca->rho = ca->rho_3ls >> 3; ca->rho2_7ls = (ca->rho_3ls * ca->rho_3ls) << 1; ca->rho2 = ca->rho2_7ls >> 7; } static void hybla_init(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct hybla *ca = inet_csk_ca(sk); ca->rho = 0; ca->rho2 = 0; ca->rho_3ls = 0; ca->rho2_7ls = 0; ca->snd_cwnd_cents = 0; ca->hybla_en = true; tp->snd_cwnd = 2; tp->snd_cwnd_clamp = 65535; /* 1st Rho measurement based on initial srtt */ hybla_recalc_param(sk); /* set minimum rtt as this is the 1st ever seen */ ca->minrtt_us = tp->srtt_us; tp->snd_cwnd = ca->rho; } static void hybla_state(struct sock *sk, u8 ca_state) { struct hybla *ca = inet_csk_ca(sk); ca->hybla_en = (ca_state == TCP_CA_Open); } static inline u32 hybla_fraction(u32 odds) { static const u32 fractions[] = { 128, 139, 152, 165, 181, 197, 215, 234, }; return (odds < ARRAY_SIZE(fractions)) ? fractions[odds] : 128; } /* TCP Hybla main routine. * This is the algorithm behavior: * o Recalc Hybla parameters if min_rtt has changed * o Give cwnd a new value based on the model proposed * o remember increments <1 */ static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 acked) { struct tcp_sock *tp = tcp_sk(sk); struct hybla *ca = inet_csk_ca(sk); u32 increment, odd, rho_fractions; int is_slowstart = 0; /* Recalculate rho only if this srtt is the lowest */ if (tp->srtt_us < ca->minrtt_us) { hybla_recalc_param(sk); ca->minrtt_us = tp->srtt_us; } if (!tcp_is_cwnd_limited(sk)) return; if (!ca->hybla_en) { tcp_reno_cong_avoid(sk, ack, acked); return; } if (ca->rho == 0) hybla_recalc_param(sk); rho_fractions = ca->rho_3ls - (ca->rho << 3); if (tcp_in_slow_start(tp)) { /* * slow start * INC = 2^RHO - 1 * This is done by splitting the rho parameter * into 2 parts: an integer part and a fraction part. * Inrement<<7 is estimated by doing: * [2^(int+fract)]<<7 * that is equal to: * (2^int) * [(2^fract) <<7] * 2^int is straightly computed as 1<rho, 16U)) * hybla_fraction(rho_fractions)) - 128; } else { /* * congestion avoidance * INC = RHO^2 / W * as long as increment is estimated as (rho<<7)/window * it already is <<7 and we can easily count its fractions. */ increment = ca->rho2_7ls / tp->snd_cwnd; if (increment < 128) tp->snd_cwnd_cnt++; } odd = increment % 128; tp->snd_cwnd += increment >> 7; ca->snd_cwnd_cents += odd; /* check when fractions goes >=128 and increase cwnd by 1. */ while (ca->snd_cwnd_cents >= 128) { tp->snd_cwnd++; ca->snd_cwnd_cents -= 128; tp->snd_cwnd_cnt = 0; } /* check when cwnd has not been incremented for a while */ if (increment == 0 && odd == 0 && tp->snd_cwnd_cnt >= tp->snd_cwnd) { tp->snd_cwnd++; tp->snd_cwnd_cnt = 0; } /* clamp down slowstart cwnd to ssthresh value. */ if (is_slowstart) tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh); tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp); } static struct tcp_congestion_ops tcp_hybla __read_mostly = { .init = hybla_init, .ssthresh = tcp_reno_ssthresh, .undo_cwnd = tcp_reno_undo_cwnd, .cong_avoid = hybla_cong_avoid, .set_state = hybla_state, .owner = THIS_MODULE, .name = "hybla" }; static int __init hybla_register(void) { BUILD_BUG_ON(sizeof(struct hybla) > ICSK_CA_PRIV_SIZE); return tcp_register_congestion_control(&tcp_hybla); } static void __exit hybla_unregister(void) { tcp_unregister_congestion_control(&tcp_hybla); } module_init(hybla_register); module_exit(hybla_unregister); MODULE_AUTHOR("Daniele Lacamera"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("TCP Hybla"); 468 (patch) tree55703c2ea8584e303e342090614e0aab3509ab21 /net/appletalk/Makefile parent0b3589be9b98994ce3d5aeca52445d1f5627c4ba (diff)
perf/x86/intel/rapl: Make package handling more robust
The package management code in RAPL relies on package mapping being available before a CPU is started. This changed with: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") because the ACPI/BIOS information turned out to be unreliable, but that left RAPL in broken state. This was not noticed because on a regular boot all CPUs are online before RAPL is initialized. A possible fix would be to reintroduce the mess which allocates a package data structure in CPU prepare and when it turns out to already exist in starting throw it away later in the CPU online callback. But that's a horrible hack and not required at all because RAPL becomes functional for perf only in the CPU online callback. That's correct because user space is not yet informed about the CPU being onlined, so nothing caan rely on RAPL being available on that particular CPU. Move the allocation to the CPU online callback and simplify the hotplug handling. At this point the package mapping is established and correct. This also adds a missing check for available package data in the event_init() function. Reported-by: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/appletalk/Makefile')