X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fgc.lisp;h=2389750c02cc62a31c51ef7fac13e766308eb954;hb=d61775ee52828f379eb6acedca421d5a55bfa2bd;hp=30cd93da5bc91661d29d72e2d86500c6de781454;hpb=934b35cf683bacd5c15842a5012f852589ae2314;p=sbcl.git diff --git a/src/code/gc.lisp b/src/code/gc.lisp index 30cd93d..2389750 100644 --- a/src/code/gc.lisp +++ b/src/code/gc.lisp @@ -33,27 +33,29 @@ #!-sb-fluid (declaim (inline dynamic-usage)) ; to reduce PROFILEd call overhead -#!+(or cgc gencgc) +#!+gencgc (def-c-var-frob dynamic-usage "bytes_allocated") -#!-(or cgc gencgc) +#!-gencgc (defun dynamic-usage () (the (unsigned-byte 32) (- (sb!sys:sap-int (sb!c::dynamic-space-free-pointer)) (current-dynamic-space-start)))) (defun static-space-usage () - (- (* sb!vm:*static-space-free-pointer* sb!vm:word-bytes) + (- (* sb!vm:*static-space-free-pointer* sb!vm:n-word-bytes) sb!vm:static-space-start)) (defun read-only-space-usage () - (- (* sb!vm::*read-only-space-free-pointer* sb!vm:word-bytes) + (- (* sb!vm::*read-only-space-free-pointer* sb!vm:n-word-bytes) sb!vm:read-only-space-start)) (defun control-stack-usage () - #!-x86 (- (sb!sys:sap-int (sb!c::control-stack-pointer-sap)) - sb!vm:control-stack-start) - #!+x86 (- sb!vm:control-stack-end - (sb!sys:sap-int (sb!c::control-stack-pointer-sap)))) + #!-stack-grows-downward-not-upward + (- (sb!sys:sap-int (sb!c::control-stack-pointer-sap)) + sb!vm:control-stack-start) + #!+stack-grows-downward-not-upward + (- sb!vm:control-stack-end + (sb!sys:sap-int (sb!c::control-stack-pointer-sap)))) (defun binding-stack-usage () (- (sb!sys:sap-int (sb!c::binding-stack-pointer-sap)) @@ -68,13 +70,13 @@ (format t "Control stack usage is: ~10:D bytes.~%" (control-stack-usage)) (format t "Binding stack usage is: ~10:D bytes.~%" (binding-stack-usage)) (format t "Garbage collection is currently ~:[enabled~;DISABLED~].~%" - *gc-inhibit*)) + (> *gc-inhibit* 0))) (defun room-intermediate-info () (room-minimal-info) (sb!vm:memory-usage :count-spaces '(:dynamic) :print-spaces t - :cutoff 0.05s0 + :cutoff 0.05f0 :print-summary nil)) (defun room-maximal-info () @@ -140,7 +142,14 @@ and submit it as a patch." ;;; ;;; Unlike CMU CL, we don't export this variable. (There's no need to, ;;; since our BYTES-CONSED-BETWEEN-GCS function is SETFable.) -(defvar *bytes-consed-between-gcs* (* 4 (expt 10 6))) +(defvar *bytes-consed-between-gcs* + #!+gencgc (* 4 (expt 10 6)) + ;; Stop-and-copy GC is really really slow when used too often. CSR + ;; reported that even on his old 64 Mb SPARC, 20 Mb is much faster + ;; than 4 Mb when rebuilding SBCL ca. 0.7.1. For modern machines + ;; with >> 128 Mb memory, the optimum could be significantly more + ;; than this, but at least 20 Mb should be better than 4 Mb. + #!-gencgc (* 20 (expt 10 6))) (declaim (type index *bytes-consed-between-gcs*)) ;;;; GC hooks @@ -170,27 +179,51 @@ and submit it as a patch." ;;; a limit to help catch programs which allocate too much memory, ;;; since a hard heap overflow is so hard to recover from +;;; +;;; FIXME: Like *GC-TRIGGER*, this variable (1) should probably be +;;; denominated in a larger unit than bytes and (2) should probably be +;;; renamed so that it's clear from the name what unit it's +;;; denominated in. (declaim (type (or unsigned-byte null) *soft-heap-limit*)) -(defvar *soft-heap-limit* nil) +(defvar *soft-heap-limit* + ;; As long as *GC-TRIGGER* is DECLAIMed as INDEX, we know that + ;; MOST-POSITIVE-FIXNUM is a hard limit on how much memory can be + ;; allocated. (Not necessarily *the* hard limit, which is fairly + ;; likely something like a Unix per-process limit that we don't know + ;; about, but a hard limit anyway.) And this gives us a reasonable + ;; conservative default for the soft limit... + (- most-positive-fixnum + *bytes-consed-between-gcs*)) + +;;;; The following specials are used to control when garbage +;;;; collection occurs. ;;; When the dynamic usage increases beyond this amount, the system ;;; notes that a garbage collection needs to occur by setting ;;; *NEED-TO-COLLECT-GARBAGE* to T. It starts out as NIL meaning ;;; nobody has figured out what it should be yet. -(defvar *gc-trigger* nil) - +;;; +;;; FIXME: *GC-TRIGGER* seems to be denominated in bytes, not words. +;;; And limiting it to INDEX is fairly reasonable in order to avoid +;;; bignum arithmetic on every allocation, and to minimize the need +;;; for thought about weird gotchas of the GC-control mechanism itself +;;; consing as it operates. But as of sbcl-0.7.5, 512Mbytes of memory +;;; costs $54.95 at Fry's in Dallas but cheap consumer 64-bit machines +;;; are still over the horizon, so gratuitously limiting our heap size +;;; to FIXNUM bytes seems fairly stupid. It'd be reasonable to +;;; (1) allow arbitrary UNSIGNED-BYTE values of *GC-TRIGGER*, or +;;; (2) redenominate this variable in words instead of bytes, postponing +;;; the problem to heaps which exceed 50% of the machine's address +;;; space, or even +;;; (3) redemoninate this variable in CONS-sized two-word units, +;;; allowing it to cover the entire memory space at the price of +;;; possible loss of clarity. +;;; (And whatever is done, it'd also be good to rename the variable so +;;; that it's clear what unit it's denominated in.) (declaim (type (or index null) *gc-trigger*)) +(defvar *gc-trigger* nil) -;;; On the X86, we store the GC trigger in a ``static'' symbol instead -;;; of letting magic C code handle it. It gets initialized by the -;;; startup code. -#!+x86 -(defvar sb!vm::*internal-gc-trigger*) - -;;;; The following specials are used to control when garbage collection -;;;; occurs. - -;;; When non-NIL, inhibits garbage collection. +;;; When >0, inhibits garbage collection. (defvar *gc-inhibit*) ; initialized in cold init ;;; This flag is used to prevent recursive entry into the garbage @@ -203,14 +236,15 @@ and submit it as a patch." (defun default-gc-notify-before (notify-stream bytes-in-use) (declare (type stream notify-stream)) - (format notify-stream - "~&; GC is beginning with ~:D bytes in use at internal runtime ~:D.~%" - bytes-in-use - (get-internal-run-time)) + (format + notify-stream + "~&; GC is beginning with ~:D bytes in use at internal runtime ~:D.~%" + bytes-in-use + (get-internal-run-time)) (finish-output notify-stream)) (defparameter *gc-notify-before* #'default-gc-notify-before #!+sb-doc - "This function bound to this variable is invoked before GC'ing (unless + "The function bound to this variable is invoked before GC'ing (unless *GC-NOTIFY-STREAM* is NIL) with the value of *GC-NOTIFY-STREAM* and current amount of dynamic usage (in bytes). It should notify the user that the system is going to GC.") @@ -230,21 +264,21 @@ and submit it as a patch." (finish-output notify-stream)) (defparameter *gc-notify-after* #'default-gc-notify-after #!+sb-doc - "The function bound to this variable is invoked after GC'ing with -the value of *GC-NOTIFY-STREAM*, the amount of dynamic usage (in -bytes) now free, the number of bytes freed by the GC, and the new GC -trigger threshold. The function should notify the user that the system -has finished GC'ing.") + "The function bound to this variable is invoked after GC'ing with the +value of *GC-NOTIFY-STREAM*, the amount of dynamic usage (in bytes) now +free, the number of bytes freed by the GC, and the new GC trigger +threshold; or if *GC-NOTIFY-STREAM* is NIL, it's not invoked. The +function should notify the user that the system has finished GC'ing.") ;;;; internal GC -(sb!alien:def-alien-routine collect-garbage sb!c-call:int - #!+gencgc (last-gen sb!c-call:int)) +(sb!alien:define-alien-routine collect-garbage sb!alien:int + (#!+gencgc last-gen #!-gencgc ignore sb!alien:int)) -(sb!alien:def-alien-routine set-auto-gc-trigger sb!c-call:void - (dynamic-usage sb!c-call:unsigned-long)) +(sb!alien:define-alien-routine set-auto-gc-trigger sb!alien:void + (dynamic-usage sb!alien:unsigned-long)) -(sb!alien:def-alien-routine clear-auto-gc-trigger sb!c-call:void) +(sb!alien:define-alien-routine clear-auto-gc-trigger sb!alien:void) ;;; This variable contains the function that does the real GC. This is ;;; for low-level GC experimentation. Do not touch it if you do not @@ -253,7 +287,7 @@ has finished GC'ing.") ;;;; SUB-GC -;;; Used to carefully invoke hooks. +;;; This is used to carefully invoke hooks. (eval-when (:compile-toplevel :execute) (sb!xc:defmacro carefully-funcall (function &rest args) `(handler-case (funcall ,function ,@args) @@ -266,6 +300,13 @@ has finished GC'ing.") ;;; is not greater than *GC-TRIGGER*. ;;; ;;; For GENCGC all generations < GEN will be GC'ed. + +;;; XXX need (1) some kind of locking to ensure that only one thread +;;; at a time is trying to GC, (2) to look at all these specials and +;;; work out how much of this "do we really need to GC now?" stuff is +;;; actually necessary: I think we actually end up GCing every time we +;;; hit this code + (defun sub-gc (&key force-p (gen 0)) (/show0 "entering SUB-GC") (unless *already-maybe-gcing* @@ -284,12 +325,12 @@ has finished GC'ing.") *soft-heap-limit*))) (when soft-heap-limit-exceeded? (cerror "Continue with GC." - "soft heap limit exceeded (temporary new limit=~D)" + "soft heap limit exceeded (temporary new limit=~W)" *soft-heap-limit*)) (when (and *gc-trigger* (> pre-gc-dynamic-usage *gc-trigger*)) (setf *need-to-collect-garbage* t)) (when (or force-p - (and *need-to-collect-garbage* (not *gc-inhibit*))) + (and *need-to-collect-garbage* (zerop *gc-inhibit*))) ;; KLUDGE: Wow, we really mask interrupts all the time we're ;; collecting garbage? That seems like a long time.. -- WHN 19991129 (without-interrupts @@ -315,17 +356,7 @@ has finished GC'ing.") ;; triggered GC could've done a fair amount of ;; consing.) (pre-internal-gc-dynamic-usage (dynamic-usage)) - (ignore-me - #!-gencgc (funcall *internal-gc*) - ;; FIXME: This EQ test is pretty gross. Among its other - ;; nastinesses, it looks as though it could break if we - ;; recompile COLLECT-GARBAGE. We should probably just - ;; straighten out the interface so that all *INTERNAL-GC* - ;; functions accept a GEN argument (and then the - ;; non-generational ones just ignore it). - #!+gencgc (if (eq *internal-gc* #'collect-garbage) - (funcall *internal-gc* gen) - (funcall *internal-gc*))) + (ignore-me (funcall *internal-gc* gen)) (post-gc-dynamic-usage (dynamic-usage)) (n-bytes-freed (- pre-internal-gc-dynamic-usage post-gc-dynamic-usage)) @@ -428,7 +459,7 @@ has finished GC'ing.") (defun gc-on () #!+sb-doc "Enable the garbage collector." - (setq *gc-inhibit* nil) + (setq *gc-inhibit* 0) (when *need-to-collect-garbage* (sub-gc)) nil) @@ -436,7 +467,7 @@ has finished GC'ing.") (defun gc-off () #!+sb-doc "Disable the garbage collector." - (setq *gc-inhibit* t) + (setq *gc-inhibit* 1) nil) ;;;; initialization stuff