Changing WSQUOTA/WSEXTENT of a running program
Oleg V.Solovyanov, IHEP
Hello, netters !
The problem is rather stupid, and there are a lot
of ways to avoid it, but simply:
Is there any way in VMS to change working set quota
and extent of a running program ?
And in what block that information resides ?
PCB,PHD, maybe JIB ?
---
Oleg
----------------------------------------------------------
Oleg V.Solovyanov Institute for High Energy Physics
solov...@mx.ihep.su
Arne Vajhoej
> of ways to avoid it, but simply:
>
> Is there any way in VMS to change working set quota
> and extent of a running program ?
>
> And in what block that information resides ?
> PCB,PHD, maybe JIB ?
The relevant fields must be:
PHD$L_WSQUOTA
PHD$L_WSEXTENT
But I have no idea about what will happend, if one enters kernel mode and
changes those two fields. If you have a workstation WITH NO OTHER USERS,
then you can try it yourself !
Arne
Arne Vajhøj local DECNET: KO::ARNE
Computer Department PSI: PSI%238310013040::ARNE
Business School of Southern Denmark Internet: AR...@KO.HHS.DK
Kenneth Adelman
>
> Hello, netters !
>
> The problem is rather stupid, and there are a lot
> of ways to avoid it, but simply:
>
> Is there any way in VMS to change working set quota
> and extent of a running program ?
>
> And in what block that information resides ?
> PCB,PHD, maybe JIB ?
PHD, which means that you need to queue an AST into the process
context to access the information. Here is some example code which
does that. To update to modern versions of VMS you'll probably need
to promote some of the PHD$W_s to PHD$L_s.
Ken
.title setwork-kernel
;
; SETWORK - short routine to queue a special kernel AST to another
; process to change its working set limit, quota, and extent.
;
; Kenneth Adelman; Nov 1987
;
; 4(AP) = PID
; 8(AP) = LIMIT
; 12(AP) = QUOTA
; 16(AP) = EXTENT
;
.library /SYS$LIBRARY:LIB/
$acbdef
spec_limit = acb$c_length
spec_quota = acb$c_length+4
spec_extent = acb$c_length+8
code_off = acb$c_length+12
$dyndef
$ipldef
$ssdef
$pcbdef
$phddef
$pridef
.macro minw2,x,y,?l
cmpw x,y
bgtru l
movw x,y
l:
.endm
.macro maxw2,x,y,?l
cmpw x,y
blssu l
movw x,y
l:
.endm
.entry pokewset,^m<r2,r3,r4,r5,r6>
;
; Get the internal PID of the process to queue the nASTy by
;
movl 4(ap),r0
jsb g^exe$epid_to_ipid
tstl r0
beql nonproc
movl r0,r6 ;save ipid
;
; Allocate a buffer to hold the ACB, three longwords of data, and the
; AST code.
;
movl #codelen+code_off,r1
jsb g^exe$allocbuf
blbs r0,10$
ret
10$: movl r2,r5 ;save address
;
; Fill in the ACB
;
movl r6,acb$l_pid(r5)
movb #dyn$c_acb,acb$b_type(r5)
movw r1,acb$w_size(r5)
movb #1@acb$v_kast,acb$b_rmod(r5)
movab code_off(r5),acb$l_kast(r5)
;
; Copy the working set sizes and the code.
;
movl 8(ap),spec_limit(r5)
movl 12(ap),spec_quota(r5)
movl 16(ap),spec_extent(r5)
pushl r5
movc3 #codelen,w^code,@acb$l_kast(r5)
popl r5
;
; Queue the nASTy
;
movzbl #pri$_ticom,r2 ;set priority increment class
movzwl acb$l_pid(r5),r0 ;destination pid
begin_lock:
dsbint lock_ipl
jsb g^sch$qast
enbint
ret
lock_ipl:
.long ipl$_synch
end_lock:
assume <end_lock-begin_lock> le 512
nonproc:
movl #ss$_nonexpr,r0
ret
;
; This *PIC* code executes in the context of the target.
;
code:
movl g^ctl$gl_phd,r1
pushr #^m<r8,r9,r10,r11>
; min_wset = phd->phd$w_wsdyn - phd->phd$w_wslist +
; 2 * phd->phd$w_wsfluid + 3;
subw3 #1,phd$w_wslist(r1),r0
mulw3 #2,phd$w_wsfluid(r1),r8
addw2 #2,r8
addw2 phd$w_wsdyn(r1),r8
subw2 r0,r8
; if (spec_limit) {
; limit = min(auth_limit,max(min_wset,spec_limit));
; } else {
; limit = phd->phd$w_dfwscnt - phd->phd$w_wslist + 1;
; }
movw spec_limit(r5),r9
beql 10$
maxw2 r8,r9
brb 11$
10$: subw3 r0,phd$w_dfwscnt(r1),r9
11$:
; if (spec_quota) {
; quota = min(auth_limit,max(min_wset,spec_quota));
; } else {
; quota = phd->phd$w_wsquota - phd->phd$w_wslist + 1;
; }
movw spec_quota(r5),r10
beql 20$
maxw2 r8,r10
brb 21$
20$: subw3 r0,phd$w_wsquota(r1),r10
21$:
; if (spec_extent) {
; extent = min(auth_extent,max(min_wset,spec_extent));
; } else {
; extent = phd->phd$w_wsext - phd->phd$w_wslist + 1;
; }
movw spec_extent(r5),r11
beql 30$
maxw2 r8,r11
brb 31$
30$: subw3 r0,phd$w_wsextent(r1),r11
31$:
; extent = max(limit, extent);
; quota = max(limit, quota);
maxw2 r9,r10
maxw2 r10,r11
; phd->phd$w_dfwscnt = phd->w_wslist - 1 + limit;
; phd->phd$w_wsquota = phd->w_wslist - 1 + quota;
; phd->phd$w_wsextent = phd->w_wslist - 1 + extent;
addw3 r0,r9,phd$w_dfwscnt(r1)
addw3 r0,r10,phd$w_wsquota(r1)
addw3 r0,r11,phd$w_wsextent(r1)
maxw2 phd$w_wsquota(r1),phd$w_wsauth(r1)
maxw2 phd$w_wsextent(r1),phd$w_wsauthext(r1)
;
; After changing the working set limits, check to see if this
; process is over its limit. If it is, $ADJWSL it down.
;
addw3 phd$w_wssize(r1),phd$w_wslist(r1),r8
movw phd$w_wsquota(r1),r9
cmpl g^sch$gl_borrowlim,g^sch$gl_freecnt
bgtru 40$
movw phd$w_wsextent(r1),r9
40$: subw r8,r9 ; r8 contains the number of pages to adjust by
bgequ 50$ ; if the overdraft < 0, WS is ok
clrl -(sp) ; return ws
cvtwl r9,-(sp)
calls #2,g^sys$adjwsl
50$:
popr #^m<r8,r9,r10,r11>
setipl #ipl$_astdel
movl r5,r0
jmp @#exe$deanonpaged
codelen = .-code
.end