(total (required-argument) :type single-float :read-only t))
(defvar *overhead*)
(declaim (type overhead *overhead*))
+(makunbound '*overhead*) ; in case we reload this file when tweaking
\f
;;;; profile encapsulations
;;; inline.
(defmacro fastbig- (x y)
(once-only ((x x) (y y))
- `(if (and (typep ,x 'fixnum)
- (typep ,y 'fixnum))
+ `(if (and (typep ,x '(and fixnum unsigned-byte))
+ (typep ,y '(and fixnum unsigned-byte)))
+ ;; special case: can use fixnum arithmetic and be guaranteed
+ ;; the result is also a fixnum
(- ,x ,y)
+ ;; general case
(- ,x ,y))))
(defmacro fastbig-1+ (x)
(once-only ((x x))
(aver (typep dconsing 'unsigned-byte))
(aver (typep inner-enclosed-profiles 'unsigned-byte))
(multiple-value-prog1
- (let ((start-ticks (get-internal-ticks))
- (start-consing (get-bytes-consed))
- (*enclosed-ticks* 0)
- (*enclosed-consing* 0)
- (*enclosed-profiles* 0))
+ (let* ((start-ticks (get-internal-ticks))
+ (*enclosed-ticks* 0)
+ (*enclosed-consing* 0)
+ (*enclosed-profiles* 0)
+ (nbf-pcounter *n-bytes-freed-or-purified-pcounter*)
+ ;; Typically NBF-PCOUNTER will represent a bignum.
+ ;; In general we don't want to cons up a new
+ ;; bignum for every encapsulated call, so instead
+ ;; we keep track of the PCOUNTER internals, so
+ ;; that as long as we only cons small amounts,
+ ;; we'll almost always just do fixnum arithmetic.
+ ;; (And for encapsulated functions which cons
+ ;; large amounts, then a single extra consed
+ ;; bignum tends to be proportionally negligible.)
+ (nbf0-integer (pcounter-integer nbf-pcounter))
+ (nbf0-fixnum (pcounter-fixnum nbf-pcounter))
+ (dynamic-usage-0 (sb-kernel:dynamic-usage)))
(declare (inline pcounter-or-fixnum->integer))
(multiple-value-prog1
(multiple-value-call encapsulated-fun
(sb-c:%more-arg-values arg-context
0
arg-count))
- (let ((*computing-profiling-data-for* encapsulated-fun))
- (setf dticks (fastbig- (get-internal-ticks) start-ticks)
- dconsing (fastbig- (get-bytes-consed) start-consing))
+ (let ((*computing-profiling-data-for* encapsulated-fun)
+ (dynamic-usage-1 (sb-kernel:dynamic-usage)))
+ (setf dticks (fastbig- (get-internal-ticks) start-ticks))
+ (setf dconsing
+ (if (and (eq (pcounter-integer nbf-pcounter)
+ nbf0-integer)
+ (eq (pcounter-fixnum nbf-pcounter)
+ nbf0-fixnum))
+ ;; common special case where we can avoid
+ ;; bignum arithmetic
+ (- dynamic-usage-1
+ dynamic-usage-0)
+ ;; general case
+ (- (get-bytes-consed)
+ nbf0-integer
+ nbf0-fixnum
+ dynamic-usage-0)))
(setf inner-enclosed-profiles
(pcounter-or-fixnum->integer *enclosed-profiles*))
(let ((net-dticks (fastbig- dticks *enclosed-ticks*)))
;;;; overhead estimation
;;; We average the timing overhead over this many iterations.
-(defconstant +timer-overhead-iterations+
- 50000)
+;;;
+;;; (This is a variable, not a constant, so that it can be set in
+;;; .sbclrc if desired. Right now, that's an unsupported extension
+;;; that I (WHN) use for my own experimentation, but it might
+;;; become supported someday. Comments?)
+(declaim (type unsigned-byte *timer-overhead-iterations*))
+(defparameter *timer-overhead-iterations*
+ 500000)
;;; a dummy function that we profile to find profiling overhead
(declaim (notinline compute-overhead-aux))
;;; Return a newly computed OVERHEAD object.
(defun compute-overhead ()
+ (format *debug-io* "~&measuring PROFILE overhead..")
(flet ((frob ()
(let ((start (get-internal-ticks))
(fun (symbol-function 'compute-overhead-aux)))
- (dotimes (i +timer-overhead-iterations+)
+ (dotimes (i *timer-overhead-iterations*)
(funcall fun fun))
(/ (float (- (get-internal-ticks) start))
(float +ticks-per-second+)
- (float +timer-overhead-iterations+)))))
+ (float *timer-overhead-iterations*)))))
(let (;; Measure unprofiled calls to estimate call overhead.
(call-overhead (frob))
total-overhead
(setf internal-overhead
(/ (float time)
(float +ticks-per-second+)
- (float +timer-overhead-iterations+))))
+ (float *timer-overhead-iterations*))))
(unprofile compute-overhead-aux))
- (make-overhead :call call-overhead
- :total total-overhead
- :internal internal-overhead))))
+ (prog1
+ (make-overhead :call call-overhead
+ :total total-overhead
+ :internal internal-overhead)
+ (format *debug-io* "done~%")))))
;;; It would be bad to compute *OVERHEAD*, save it into a .core file,
-;;; then load old *OVERHEAD* value from the .core file into a
+;;; then load the old *OVERHEAD* value from the .core file into a
;;; different machine running at a different speed. We avoid this by
;;; erasing *CALL-OVERHEAD* whenever we save a .core file.
(pushnew (lambda ()
projects / sbcl.git / blobdiff