diff options
Diffstat (limited to 'sysdeps/mach/hurd/profil.c')
| -rw-r--r-- | sysdeps/mach/hurd/profil.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/sysdeps/mach/hurd/profil.c b/sysdeps/mach/hurd/profil.c index 43456ec..431982e 100644 --- a/sysdeps/mach/hurd/profil.c +++ b/sysdeps/mach/hurd/profil.c @@ -1,5 +1,5 @@ /* Low-level statistical profiling support function. Mach/Hurd version. -Copyright (C) 1995 Free Software Foundation, Inc. +Copyright (C) 1995, 1996 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -26,6 +26,8 @@ Cambridge, MA 02139, USA. */ #include <cthreads.h> #include <assert.h> +#define MAX_PC_SAMPLES 512 /* XXX ought to be exported in kernel hdr */ + static thread_t profile_thread = MACH_PORT_NULL; static u_short *samples; static size_t maxsamples; @@ -33,6 +35,7 @@ static size_t pc_offset; static size_t sample_scale; static sampled_pc_seqno_t seqno; static struct mutex lock = MUTEX_INITIALIZER; +static mach_msg_timeout_t collector_timeout; /* ms between collections. */ /* Enable statistical profiling, writing samples of the PC into at most SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling @@ -59,7 +62,12 @@ update_waiter (u_short *sample_buffer, size_t size, size_t offset, u_int scale) if (! err) { - if (sample_scale == 0) + int tick; /* Microseconds per sample. */ + err = __task_enable_pc_sampling (__mach_task_self (), &tick, + SAMPLED_PC_PERIODIC); + if (!err && sample_scale == 0) + /* Profiling was not turned on, so the collector thread was + suspended. Resume it. */ err = __thread_resume (profile_thread); if (! err) { @@ -67,6 +75,11 @@ update_waiter (u_short *sample_buffer, size_t size, size_t offset, u_int scale) maxsamples = size / sizeof *sample_buffer; pc_offset = offset; sample_scale = scale; + /* Calculate a good period for the collector thread. From TICK + and the kernel buffer size we get the length of time it takes + to fill the buffer; translate that to milliseconds for + mach_msg, and chop it in half for general lag factor. */ + collector_timeout = MAX_PC_SAMPLES * tick / 1000 / 2; } } @@ -100,17 +113,17 @@ profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale) static void profile_waiter (void) { - sampled_pc_t pc_samples[512]; - mach_msg_type_number_t nsamples = 512, i; + sampled_pc_t pc_samples[MAX_PC_SAMPLES]; + mach_msg_type_number_t nsamples, i; mach_port_t rcv = __mach_reply_port (); mach_msg_header_t msg; - const mach_msg_timeout_t timeout = 17; /* ??? XXX */ error_t err; while (1) { __mutex_lock (&lock); + nsamples = sizeof pc_samples / sizeof pc_samples[0]; err = __task_get_sampled_pcs (__mach_task_self (), &seqno, pc_samples, &nsamples); assert_perror (err); @@ -130,7 +143,7 @@ profile_waiter (void) __mutex_unlock (&lock); __mach_msg (&msg, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof msg, - rcv, timeout, MACH_PORT_NULL); + rcv, collector_timeout, MACH_PORT_NULL); } } |