#include #include #include #include "../../perf.h" #include #include "../../util/debug.h" #include "../../util/tsc.h" int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc, struct perf_tsc_conversion *tc) { bool cap_user_time_zero; u32 seq; int i = 0; while (1) { seq = pc->lock; rmb(); tc->time_mult = pc->time_mult; tc->time_shift = pc->time_shift; tc->time_zero = pc->time_zero; cap_user_time_zero = pc->cap_user_time_zero; rmb(); if (pc->lock == seq && !(seq & 1)) break; if (++i > 10000) { pr_debug("failed to get perf_event_mmap_page lock\n"); return -EINVAL; } } if (!cap_user_time_zero) return -EOPNOTSUPP; return 0; } u64 rdtsc(void) { unsigned int low, high; asm volatile("rdtsc" : "=a" (low), "=d" (high)); return low | ((u64)high) << 32; } int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc, struct perf_tool *tool, perf_event__handler_t process, struct machine *machine) { union perf_event event = { .time_conv = { .header = { .type = PERF_RECORD_TIME_CONV, .size = sizeof(struct time_conv_event), }, }, }; struct perf_tsc_conversion tc; int err; if (!pc) return 0; err = perf_read_tsc_conversion(pc, &tc); if (err == -EOPNOTSUPP) return 0; if (err) return err; pr_debug2("Synthesizing TSC conversion information\n"); event.time_conv.time_mult = tc.time_mult; event.time_conv.time_shift = tc.time_shift; event.time_conv.time_zero = tc.time_zero; return process(tool, &event, NULL, machine); } xt.git/?h=nds-private-remove'>summaryrefslogtreecommitdiff
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authorDexuan Cui <decui@microsoft.com>2017-01-28 11:46:02 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-31 10:59:48 +0100
commit433e19cf33d34bb6751c874a9c00980552fe508c (patch)
treece6547ef2987fbb289fa28f03536328a42781651 /drivers/usb/Makefile
parent191e885a2e130e639bb0c8ee350d7047294f2ce6 (diff)
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/Makefile')