/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include #include #include #include #include "bpf_helpers.h" struct bpf_map_def SEC("maps") my_map = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(long), .value_size = sizeof(u64), .max_entries = 4096, }; /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe * example will no longer be meaningful */ SEC("kprobe/blk_start_request") int bpf_prog1(struct pt_regs *ctx) { long rq = PT_REGS_PARM1(ctx); u64 val = bpf_ktime_get_ns(); bpf_map_update_elem(&my_map, &rq, &val, BPF_ANY); return 0; } static unsigned int log2l(unsigned long long n) { #define S(k) if (n >= (1ull << k)) { i += k; n >>= k; } int i = -(n == 0); S(32); S(16); S(8); S(4); S(2); S(1); return i; #undef S } #define SLOTS 100 struct bpf_map_def SEC("maps") lat_map = { .type = BPF_MAP_TYPE_PERCPU_ARRAY, .key_size = sizeof(u32), .value_size = sizeof(u64), .max_entries = SLOTS, }; SEC("kprobe/blk_account_io_completion") int bpf_prog2(struct pt_regs *ctx) { long rq = PT_REGS_PARM1(ctx); u64 *value, l, base; u32 index; value = bpf_map_lookup_elem(&my_map, &rq); if (!value) return 0; u64 cur_time = bpf_ktime_get_ns(); u64 delta = cur_time - *value; bpf_map_delete_elem(&my_map, &rq); /* the lines below are computing index = log10(delta)*10 * using integer arithmetic * index = 29 ~ 1 usec * index = 59 ~ 1 msec * index = 89 ~ 1 sec * index = 99 ~ 10sec or more * log10(x)*10 = log2(x)*10/log2(10) = log2(x)*3 */ l = log2l(delta); base = 1ll << l; index = (l * 64 + (delta - base) * 64 / base) * 3 / 64; if (index >= SLOTS) index = SLOTS - 1; value = bpf_map_lookup_elem(&lat_map, &index); if (value) *value += 1; return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; >diff
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authorLinus Walleij <linus.walleij@linaro.org>2016-11-12 15:22:38 +0100
committerMark Brown <broonie@kernel.org>2016-11-13 09:22:37 +0000
commit295070e9aa015abb9b92cccfbb1e43954e938133 (patch)
treed0a08e7ce280bc877e22424437dbe59fa1857d9a /net/dccp/ccids
parent1001354ca34179f3db924eb66672442a173147dc (diff)
regulator: stw481x-vmmc: fix ages old enable error
The regulator has never been properly enabled, it has been dormant all the time. It's strange that MMC was working at all, but it likely worked by the signals going through the levelshifter and reaching the card anyways. Fixes: 3615a34ea1a6 ("regulator: add STw481x VMMC driver") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
Diffstat (limited to 'net/dccp/ccids')