From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Damien Mattei Newsgroups: gmane.lisp.guile.user Subject: Re: map-par slower than map Date: Thu, 10 Nov 2022 11:41:36 +0100 Message-ID: References: <5608809c-89a2-118c-5c05-c46ac3a0e21b@posteo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="37308"; mail-complaints-to="usenet@ciao.gmane.io" Cc: guile-user To: Zelphir Kaltstahl Original-X-From: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Thu Nov 10 11:42:51 2022 Return-path: Envelope-to: guile-user@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ot51G-0009Uz-Rm for guile-user@m.gmane-mx.org; Thu, 10 Nov 2022 11:42:50 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ot50Z-0007lm-05; Thu, 10 Nov 2022 05:42:07 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ot50X-0007iY-GV for guile-user@gnu.org; Thu, 10 Nov 2022 05:42:05 -0500 Original-Received: from mail-ed1-x529.google.com ([2a00:1450:4864:20::529]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ot50I-0000xw-8X for guile-user@gnu.org; Thu, 10 Nov 2022 05:42:05 -0500 Original-Received: by mail-ed1-x529.google.com with SMTP id a13so2495632edj.0 for ; Thu, 10 Nov 2022 02:41:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=OcDXBKjye3k+KHeDKBDr3D3+fgVhO+MQ96Gblgbuuqo=; b=H6e0MPilI9GzN0eujKhjIHPZeE9PhM2tECu24UgRaVJQ1S8zOZ39DrFjkCI11lbuCb fkRYs4UydPg1TYHwvZJdkBe2/8ADeML+c2zzdDHTeJ2HeEorKijyCaHFWuXWh1HzK0Fp Og2mq3ULcX1G6FQV4N8XXXGeLmo/HVTk+8j2T8x6ZWb8U8XPFfJt9gPbL7kXcmbAUsIU Uj+lxNEdLhwWiGZVgx7hrcpzQyZBKY8sEJo/79yMYPMAtdMc+SYQvO33VOCTh5murRDx KFOAjEbz+3zvUJJ8mGcTn+AJdUVQrnb34HW0SZo8NIVv+EbofoBve6eaf06rx6f/CPiq uPiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=OcDXBKjye3k+KHeDKBDr3D3+fgVhO+MQ96Gblgbuuqo=; b=uvZ0rI3sQaYMu+PoNDxOnzV6EhYTE6o8XSrR4cVQW3VtsW47WrN/fxRPWC/zheVmp2 NlOizK53qprWPjOkJB8zMdlQs/6ZRznb2thp1F0tZCtWN3BApAio1fbLI0+SW6Daads4 DfdDp6vJ4xXitEzhzhUIESL7sQnI9fFoWQM3T1aj8oCj1wXCcahDaLHY7U2uETK/Hn32 5K8zPw88u0Gfw2nQ++RSYH7Lx7WbvkFBL7c07gkMjYoZR8WAfP83cJbeSLBeglNPuqgN TLX+Z+vyZRnw2XfegC5AuUUoiJv94079wtH8XpB+4nHoFeFyhY8cR2hR1phPl4KgmAfg +UKA== X-Gm-Message-State: ACrzQf0iu2lsh055aTLI2aOqWriRjxXwvTPK67Oq/2rsrkPNt6WfADlI 9fzE2Q/FRtLLLwULL6MmoCjdBGoDHlcvgDut7lIz7X1Y8lM= X-Google-Smtp-Source: AMsMyM5iy9rtJ+NopjkPEp5hR043mCo4L2unsHlPEvSrshklbvFk4z1d2lj2TwBT6rvGaFFqvSsap1s9X+xCl2PsMko= X-Received: by 2002:a50:ec13:0:b0:461:e3f2:38bc with SMTP id g19-20020a50ec13000000b00461e3f238bcmr2078164edr.149.1668076908482; Thu, 10 Nov 2022 02:41:48 -0800 (PST) In-Reply-To: Received-SPF: pass client-ip=2a00:1450:4864:20::529; envelope-from=damien.mattei@gmail.com; helo=mail-ed1-x529.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, SPF_PASS=-0.001, T_SPF_HELO_TEMPERROR=0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Original-Sender: guile-user-bounces+guile-user=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.lisp.guile.user:18712 Archived-At: note that it is not a Guile problem, the same code give also no speed up with Racket 'future ,i have not already test it but it should block also on 'touch future... On Thu, Nov 10, 2022 at 11:32 AM Damien Mattei wrote: > Hello Zelphir, > > i finally find a possible cause of no speed up of my code, i find that > using your code the procedure keep blocked on the first 'touch at line 27 > here: > > > https://notabug.org/ZelphirKaltstahl/guile-project-euler-solutions/src/eb= b19b11b465903105924adb6252f1e2ecf63859/lib/parallelism.scm#L27 > > if i add a 'display i got this output, see the second part ,i cut it > waiting the rest of output , it is blockers on the first 'touch until it > return ,after all the touch are fast as if all the job is done in the fir= st > 'touch > > unct-unify-minterms-set-1-unit-future : begin > set1-length =3D 930 > set2-length =3D 1270 > before Cartesian product set > after Cartesian product set > minterms-set-length =3D 1181100 > minterms-set-first =3D ((1 1 1 x x 0 0 0 0 1) (1 1 1 1 x x 0 0 0 1)) > segmts =3D ((0 . 196850) (196851 . 393701) (393702 . 590552) (590553 . > 787403) (787404 . 984254) (984255 . 1181099)) > before // > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : touching future > run-in-parallel : touching future > run-in-parallel : touching future > run-in-parallel : touching future > run-in-parallel : touching future > run-in-parallel : touching future > after // > unified-minterms-vector-1-length =3D 1181100 > > funct-unify-minterms-set-1-unit-future : end > funct-unify-minterms-set-1-unit-future : begin > set1-length =3D 1270 > set2-length =3D 888 > before Cartesian product set > after Cartesian product set > minterms-set-length =3D 1127760 > minterms-set-first =3D ((1 1 1 1 x x 0 0 0 1) (1 1 1 1 1 x x 0 0 1)) > segmts =3D ((0 . 187960) (187961 . 375921) (375922 . 563882) (563883 . > 751843) (751844 . 939804) (939805 . 1127759)) > before // > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : making future > run-in-parallel : touching future > > blocking just above > > i find no explanation in Guile doc: > > Scheme Procedure: *touch* *f* > > Return the result of the expression embedded in future f. > > If the result was already computed in parallel, touch returns > instantaneously. Otherwise, it waits for the computation to complete, if = it > already started, or initiates it. In the former case, the calling thread > may process other futures in the meantime. > perheaps 'map is not the good way to "launch" futures? > > here is my version of code with display that genrate the output above: > > (define run-in-parallel > (=CE=BB (segments map-proc) ;;reduce-proc reduce-init) > "Use futures to run a procedure in parallel, if > multiple cores are available. Take a list of SEGMENTS as > input, which are ranges of values to work on. MAP-PROC is > applied to the SEGMENTS using map. When the MAP-PROC calls > for all segments finished and returned values, the > REDUCE-PROC is applied to the map result using reduce and > the REDUCE-INIT argument." > (let ([futures > (map (=CE=BB (seg) > (display-nl "run-in-parallel : making future") > (make-future > ;; Need to wrap in a thunk, to not > ;; immediately start evaluating. > (=CE=BB () (map-proc seg)))) > segments)]) > ;;(let ([segment-results (map touch futures)]) > (let ([segment-results (map (lambda (f) > (display-nl "run-in-parallel : touching future") > (touch f)) > futures)]) > segment-results > ;; (reduce reduce-proc > ;; reduce-init > ;; segment-results) > )))) > > > Best regards, > > Damien > > On Wed, Oct 12, 2022 at 11:29 PM Zelphir Kaltstahl < > zelphirkaltstahl@posteo.de> wrote: > >> Hi! >> >> On 10/12/22 22:27, Damien Mattei wrote: >> > >> https://github.com/damien-mattei/library-FunctProg/blob/master/guile/log= iki%2B.scm#L1674 >> > >> > i commited the current version of code here with all files but it is >> > huge.... :-/ >> > >> > On Wed, Oct 12, 2022 at 10:20 PM Damien Mattei > > >> > wrote: >> > >> >> Mutex? i do not think code has situation where dead lock could happen= , >> it >> >> is a code about minimalising logic expressions, it uses minterms , >> minterms >> >> set is a set of minterms :like this: >> >> >> >> example: >> >> ((1 1 0) (1 1 1)) will be unified : (1 1 x) >> >> because 0 and 1 are replaced by x >> >> the minterms-set could have thousands of pair (mathematic not lisp) >> >> minterms to unify >> >> if there is more than one x as result there is no need to continue so= i >> >> escape with a continuation: >> >> >> >> minterms-set =3D >> >> { >> >> ((1 0 1 0) (1 1 1 0)) >> >> ((1 0 1 0) (1 1 0 1)) >> >> ((1 0 1 0) (1 0 1 1)) >> >> ((1 0 1 0) (0 1 1 1)) >> >> ((0 1 1 0) (1 1 1 0)) >> >> ((0 1 1 0) (1 1 0 1)) >> >> ((0 1 1 0) (1 0 1 1)) >> >> ((0 1 1 0) (0 1 1 1)) >> >> ((0 1 0 1) (1 1 1 0)) >> >> ((0 1 0 1) (1 1 0 1)) >> >> ((0 1 0 1) (1 0 1 1)) >> >> ((0 1 0 1) (0 1 1 1)) >> >> ((0 0 1 1) (1 1 1 0)) >> >> ((0 0 1 1) (1 1 0 1)) >> >> ((0 0 1 1) (1 0 1 1)) >> >> ((0 0 1 1) (0 1 1 1)) >> >> } >> >> >> >> replace { } by () to have the list, other example at another level : >> >> >> >> minterms-set =3D >> >> { >> >> ((0 x 1 1) (x 1 1 1)) >> >> ((0 x 1 1) (1 x 1 1)) >> >> ((0 x 1 1) (1 1 x 1)) >> >> ((0 x 1 1) (1 1 1 x)) >> >> ((x 0 1 1) (x 1 1 1)) >> >> ((x 0 1 1) (1 x 1 1)) >> >> ((x 0 1 1) (1 1 x 1)) >> >> ((x 0 1 1) (1 1 1 x)) >> >> ((0 1 x 1) (x 1 1 1)) >> >> ((0 1 x 1) (1 x 1 1)) >> >> ((0 1 x 1) (1 1 x 1)) >> >> ((0 1 x 1) (1 1 1 x)) >> >> ((x 1 0 1) (x 1 1 1)) >> >> ((x 1 0 1) (1 x 1 1)) >> >> ((x 1 0 1) (1 1 x 1)) >> >> ((x 1 0 1) (1 1 1 x)) >> >> ((0 1 1 x) (x 1 1 1)) >> >> ((0 1 1 x) (1 x 1 1)) >> >> ((0 1 1 x) (1 1 x 1)) >> >> ((0 1 1 x) (1 1 1 x)) >> >> ((x 1 1 0) (x 1 1 1)) >> >> ((x 1 1 0) (1 x 1 1)) >> >> ((x 1 1 0) (1 1 x 1)) >> >> ((x 1 1 0) (1 1 1 x)) >> >> ((1 0 1 x) (x 1 1 1)) >> >> ((1 0 1 x) (1 x 1 1)) >> >> ((1 0 1 x) (1 1 x 1)) >> >> ((1 0 1 x) (1 1 1 x)) >> >> ((1 x 1 0) (x 1 1 1)) >> >> ((1 x 1 0) (1 x 1 1)) >> >> ((1 x 1 0) (1 1 x 1)) >> >> ((1 x 1 0) (1 1 1 x)) >> >> } >> >> >> >> here we see some minterms are already unified >> >> >> >> it is not easy to read even by me because i wrote the code many >> years ago >> >> and is split in many files, but here it is: >> >> >> >> (par-map function-unify-minterms-list minterms-set) >> >> >> >> {function-unify-minterms-list <+ (=CE=BB (L) (apply >> >> function-unify-two-minterms-and-tag L))} >> >> >> >> (define (unify-two-minterms mt1 mt2) >> >> (function-map-with-escaping-by-kontinuation2 >> >> (macro-function-compare-2-bits-with-continuation) mt1 mt2)) >> >> >> >> ;; (function-map-with-escaping-by-kontinuation2 >> >> (macro-function-compare-2-bits-with-continuation) '(1 1 0 1 0 1 1 0= ) >> '(1 >> >> 1 0 1 1 1 1 1)) >> >> >> >> ;; list1 =3D (1 1 0 1 0 1 1 0) >> >> ;; more-lists =3D ((1 1 0 1 1 1 1 1)) >> >> ;; lists =3D ((1 1 0 1 0 1 1 0) (1 1 0 1 1 1 1 1)) >> >> ;; clozure =3D # >> >> >> >> ;; #f >> >> ;; >> >> ;; (function-map-with-escaping-by-kontinuation2 >> >> (macro-function-compare-2-bits-with-continuation) '(1 1 0 1 0 1 1 >> 0) '(1 >> >> 1 0 1 1 1 1 0)) >> >> >> >> ;; list1 =3D (1 1 0 1 0 1 1 0) >> >> ;; more-lists =3D ((1 1 0 1 1 1 1 0)) >> >> ;; lists =3D ((1 1 0 1 0 1 1 0) (1 1 0 1 1 1 1 0)) >> >> ;; clozure =3D # >> >> >> >> ;; '(1 1 0 1 x 1 1 0) >> >> (define (function-map-with-escaping-by-kontinuation2 clozure list1 . >> >> more-lists) >> >> (call/cc (lambda (kontinuation) >> >> (let ((lists (cons list1 more-lists)) >> >> (funct-continu ;; this function have the kontinuation in his >> environment >> >> (lambda (arg1 . more-args) >> >> (let ((args (cons arg1 more-args))) >> >> (apply clozure kontinuation args))))) ;; a tester: (apply clozure (co= ns >> >> conti args)) >> >> >> >> ;; (newline) >> >> ;; (dv list1) >> >> ;; (dv more-lists) >> >> ;; (dv lists) >> >> ;; (dv clozure) >> >> ;; (newline) >> >> >> >> (apply map funct-continu lists))))) >> >> >> >> (define-syntax macro-function-compare-2-bits-with-continuation ;; >> >> continuation version of macro-compare-2-bits >> >> ;; i need a macro because of external function to the clozure >> >> (syntax-rules () >> >> ((_) (let ((cnt 0)) ;; counter >> >> (lambda (continuation b1 b2) (if (equal? b1 b2) >> >> b1 >> >> (begin >> >> (set! cnt (add1 cnt)) ;; we leave with continuation in case cpt > >> 1, we >> >> can have used a flag too instead of a counter >> >> (when (> cnt 1) (continuation #f)) ;; escaping with the >> continuation >> >> 'x))))))) ;; return x in case of (b1,b2) =3D (O,1) or (1,0) >> >> >> >> what could have caused mutex if in the latter definition above (let >> ((cnt >> >> 0)) ;; counter was defined at top level and shared by all threads!!! >> yes >> >> there could have be some mutex but this is not the case, i think eve= n >> all >> >> function are pure so why is it more slow with // than without? >> >> Damien >> >> >> >> On Wed, Oct 12, 2022 at 8:45 PM Maxime Devos >> >> wrote: >> >> >> >>> On 12-10-2022 19:19, Damien Mattei wrote: >> >>>> Hello, >> >>>> all is in the title, i test on a approximately 30000 element list ,= i >> >>> got >> >>>> 9s with map and 3min 30s with par-map on exactly the same piece of >> >>> code!? >> >>> > [...] >> >>> > >> >>>> translated from Scheme+ to Scheme: >> >>>> (define unified-minterms-set-1 (map function-unify-minterms-list >> >>>> minterms-set)) ;;(par-map function-unify-minterms-list minterms-set= )) >> >>> The definition of 'function-unify-minterms-list' and 'minterms-set' = is >> >>> missing. Without a test case, we can only speculate what's going on= . >> >>> (E.g., maybe it grabs a mutex). >> >>> >> >>> Greetings, >> >>> Maxime. >> I don't want to scare anyone, just maybe warn about parallel map. I once >> tried >> to use Guile's parallel map function for a decision tree implementation >> ( >> https://notabug.org/ZelphirKaltstahl/guile-ml/src/cf666801fea91c9fa8fa29= 0764ff6c60b7f3949d/decision-tree.scm), >> >> where each branch while learning the tree would call parallel map again >> for sub >> branches and so on. Somehow it made Guile crash (I don't have the error >> message >> any longer, but I did post about it on the mailing list back then.). I >> never >> figured out, what went wrong. All I had was pure function calls and math >> inside >> the thing that parallel map was supposed to run. >> >> Ultimately I simply tried other parallelism constructs and when I >> switched to >> using futures instead, everything worked fine, no crashes, no errors. >> >> Since that time, I did not use parallel map and instead used futures. >> Recently I >> made a parallelization thing for solving exercises of Project Euler usin= g >> multiple cores, so that some solutions are calculated faster. Maybe this >> can >> help or can be adapted to another use case: >> >> >> https://notabug.org/ZelphirKaltstahl/guile-project-euler-solutions/src/e= bb19b11b465903105924adb6252f1e2ecf63859/lib/parallelism.scm#L11-L30 >> >> It expects ranges of things, which are called `segments` in the code. >> Usually >> ranges of numbers for Project Euler things. Here is the code to split a >> range >> into segments: >> >> >> https://notabug.org/ZelphirKaltstahl/guile-project-euler-solutions/src/e= bb19b11b465903105924adb6252f1e2ecf63859/lib/segment.scm >> >> (Check any solution using it for an example.) >> >> So this might be a bit too specific for general parallel things, but I >> guess one >> could change the way futures are used in `run-in-parallel`, to fit any >> other >> purpose. >> >> Best regards, >> Zelphir >> >> -- >> repositories: https://notabug.org/ZelphirKaltstahl >> >>