Thanks Henry, I'd be happy to. Where should I put it? A sub page of http://code.jsoftware.com/wiki/System/Interpreter/Bugs ?
On Thu, Jan 12, 2017 at 3:52 PM, Henry Rich <henryhr...@gmail.com> wrote: > Thanks for the tip. > > If you would put this into the Wiki there'll be less chance that I'll > forget about it. > > Henry Rich > > > On 1/12/2017 3:41 PM, Joe Bogner wrote: > >> It looks like there was some discussion along these lines previously: >> >> http://www.jsoftware.com/pipermail/source/2016-May/000785.html >> >> I also don't understand why gc3 is needed. It's also interesting that it >> changed some time between j v7 and the gpl source in j7 >> >> https://github.com/zeotrope/j7-src/blob/0fba52cac4035de6442c >> 2716b614d7b232e91693/cp.c#L31 >> >> >> while(k<m&&i==nv[jv[k]]){xv[jv[k]]=z; ++k;} >> gc3(x,z,0L,old); >> >> >> https://github.com/jsoftware/jsource/blob/master/jsrc/cp.c#L97 >> >> while(k<m&&i==nv[k]){xv[k]=z; ++k; q=k<m?bv[k]:0;} >> if(!(i%10))gc3(x,z,0L,old); >> >> >> It looks like the (i%10) was added to make the gc3 run less frequently - >> every 10th iteration. If there was a loop of 11, then it wouldn't execute >> on the 11th iteration, which makes me wonder why it's even there in the >> first place -- maybe to free up temporary memory? That seems like an >> expensive operation to run every 10 iterations. I could see it making >> sense >> on memory constrained systems but seems less relevant now and actually is >> very costly from a CPU perspective >> >> >> >> >> >> On Tue, Jan 10, 2017 at 9:51 PM, Joe Bogner <joebog...@gmail.com> wrote: >> >> I was investigating the slowness of this and identified a call to gc3 as >>> being the culprit >>> >>> >>> With the gc3: >>> >>> f1 =: 3 : '(>: each)^:(<y) (<0)' >>> >>> (6!:2) 'f1 100000' >>> 33.0624 >>> >>> Without it >>> >>> (6!:2) 'f1 100000' >>> 0.272726 >>> >>> >>> It still works: >>> f1 5 >>> +-+-+-+-+-+ >>> |0|1|2|3|4| >>> +-+-+-+-+-+ >>> >>> >>> Why is it doing this operation (garbage collection?) every 10 loops >>> >>> https://github.com/jsoftware/jsource/blob/e68277f408433fe34fd31f0161a31c >>> 96d9ccb44e/jsrc/cp.c#L97 >>> >>> >>> Can anyone elaborate on this? Is the 10 count too frequent? >>> >>> >>> Repeatedly running f1 100000 does not result in a memory leak as far as >>> I can tell. >>> cp.c >>> >>> static DF1(jtply1){PROLOG(0040);DECLFG;A b,hs,j,x,*xv,y,z;B*bv,q;I >>> i,k,m,n,*nv,old,p=0; >>> hs=sv->h; m=AN(hs); >>> RZ(x=ravel(hs)); RZ(y=from(j=grade1(x),x)); nv=AV(y); >>> GATV(x,BOX,m,1,0); xv=AAV(x); >>> while(p<m&&0>nv[p])p++; >>> if(p<m){ >>> RZ(z=ca(w)); >>> n=nv[m-1]; k=p; >>> while(k<m&&!nv[k]){xv[k]=z; ++k;} >>> RZ(b=eq(ainf,from(j,ravel(gs)))); bv=BAV(b); q=k<m?bv[k]:0; >>> old=jt->tnextpushx; >>> for(i=1;i<=n;++i){ >>> RZ(z=CALL1(f1,y=z,fs)); >>> if(q&&equ(y,z)){DO(m-k, xv[k]=z; ++k;); break;} >>> while(k<m&&i==nv[k]){xv[k]=z; ++k; q=k<m?bv[k]:0;} >>> if(!(i%10))gc3(x,z,0L,old); >>> }} >>> if(0<p){ >>> RZ(fs=inv(fs)); f1=VAV(fs)->f1; >>> RZ(z=ca(w)); >>> n=nv[0]; k=p-1; >>> RZ(b=eq(scf(-inf),from(j,ravel(gs)))); bv=BAV(b); q=bv[k]; >>> old=jt->tnextpushx; >>> for(i=-1;i>=n;--i){ >>> RZ(z=CALL1(f1,y=z,fs)); >>> if(q&&equ(y,z)){DO(1+k, xv[k]=z; --k;); break;} >>> while(0<=k&&i==nv[k]){xv[k]=z; --k; q=0<=k?bv[k]:0;} >>> # ----------------> if(!(i%10))gc3(x,z,0L,old); >>> }} >>> z=ope(reshape(shape(hs),from(grade1(j),x))); EPILOG(z); >>> } >>> >>> >>> >>> void jtgc3(J jt,A x,A y,A z,I old){ >>> if(x)ra(x); if(y)ra(y); if(z)ra(z); >>> tpop(old); >>> if(x)tpush(x); if(y)tpush(y); if(z)tpush(z); >>> } >>> >>> >>> >>> ---------- Forwarded message ---------- >>> From: Joe Bogner <joebog...@gmail.com> >>> Date: Tue, Jan 10, 2017 at 6:26 PM >>> Subject: Re: ^: slowness with boxes >>> To: programm...@jsoftware.com >>> >>> >>> For a little more color: previous discussion: http://www.jsoftwa >>> re.com/pipermail/programming/2014-March/035994.html >>> >>> I'm going to switch back to using i. for this >>> >>> >>> >>> On Tue, Jan 10, 2017 at 6:15 PM, Joe Bogner <joebog...@gmail.com> wrote: >>> >>> Looks like it is due to the boxing. Please disregard >>>> >>>> http://code.jsoftware.com/wiki/Vocabulary/comma#dyadic mentions that >>>> append in place special code does not work for boxes >>>> >>>> f4 =: 3 : 0 >>>> >>>> a=:a: >>>> >>>> for_n. (i. y) do. a=:a,(<n) end. >>>> >>>> ) >>>> >>>> >>>> (6!:2) 'f4 100' >>>> >>>> 0.000336555 >>>> >>>> (6!:2) 'f4 1000' >>>> >>>> 0.0149772 >>>> >>>> (6!:2) 'f4 10000' >>>> >>>> 0.667025 >>>> >>>> (6!:2) 'f4 20000' >>>> >>>> 2.69115 >>>> >>>> (6!:2) 'f4 100000' >>>> >>>> 170.261 >>>> >>>> >>>> >>>> >>>> On Tue, Jan 10, 2017 at 5:26 PM, Joe Bogner <joebog...@gmail.com> >>>> wrote: >>>> >>>> Why are these so different in execution speed? I'm surprised assembling >>>>> that linking boxes makes that much of a difference over an number. I >>>>> need >>>>> it to be boxed because I'm going to something more complex with each >>>>> iteration. >>>>> >>>>> f1 =: 3 : '(>: each)^:(<y) (<0)' >>>>> >>>>> (6!:2) 'f1 100' >>>>> 6.01622e_5 >>>>> (6!:2) 'f1 1000' >>>>> 0.0012719 >>>>> (6!:2) 'f1 10000' >>>>> 0.145702 >>>>> (6!:2) 'f1 100000' >>>>> 33.0624 >>>>> >>>>> f2 =: 3 : '(>:)^:(<y) (0)' >>>>> >>>>> (6!:2) 'f2 100' >>>>> 4.24675e_5 >>>>> (6!:2) 'f2 1000' >>>>> 0.000189688 >>>>> (6!:2) 'f2 10000' >>>>> 0.00180487 >>>>> (6!:2) 'f2 100000' >>>>> 0.0256836 >>>>> >>>>> >>>>> I'm thinking of using ^: to execute something N times with an >>>>> increasing >>>>> argument. >>>>> >>>>> I could use i. but wanted to try something different >>>>> >>>>> >>>>> JVERSION >>>>> >>>>> Engine: j805/j64/windows >>>>> >>>>> Release: commercial/2016-12-11T08:02:16 >>>>> >>>>> Library: 8.05.11 >>>>> >>>>> Qt IDE: 1.5.3s/5.6.2 >>>>> >>>>> Platform: Win 64 >>>>> >>>>> Installer: J805 install >>>>> >>>>> InstallPath: c:/program files/j64-805 >>>>> >>>>> Contact: www.jsoftware.com >>>>> >>>>> >>>> >>> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
