From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.2 required=3.0 tests=AWL,BAYES_00,BODY_8BITS, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id CE30C1F4C0 for ; Thu, 31 Oct 2019 13:13:44 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=HgQ5FEUbZL2N6Fyd qRITXLUi0LrlxAWGXf7dSE3V4S3Fb9ShBQ0rT2EZJyLzV15uVBuV4MKXoFWPm81P p7rx8H9PH6nQe2WE9v3IrK3uSVmxx+Z762/vaPEqOKYiJwWK+27EmZe3hXYrKH1b 2+0S0p/rqPH0ne7gDO+GgCaMRVE= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=zCQvLk5zIBFPs2cfcBPxJf PE7rs=; b=n3oYQCl/1g+r4C6pSquPAmnA7X7GlDHjcf9hmDJhjtxs/pDREsbyPB S13DeQ/BhTMJ0TeCgFA12umF5Q9ROm5AUyH5HfvImSl7udDTesFFf4deeiLb0cfu e1B3XzOjrDQMkuJ0/dmIyqu8ny1WFnyk0oueXlY9K1K89sCauTGdc= Received: (qmail 82245 invoked by alias); 31 Oct 2019 13:13:42 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 82236 invoked by uid 89); 31 Oct 2019 13:13:42 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: us-smtp-delivery-1.mimecast.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572527619; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uoNOQ5rgzgfS6eFWuNGa/5xJKkM4TYZCjTOjOI4HjZE=; b=c/HpWsSUlarUT91YQl6C2RI3K8RCp9Xc80kYU6UpPOLc4T/sL7WbkdRPTOxPpjfYCvcHFc GSGs89bFR2sBy54vBXYX3h4RZaHJJoeWMOS4aGX6wSgkOJ1dmpTSDNK4BdIBdYGw7e3tHb Q8qeU8g02G/6cyF3ffGrT3/epvWsrLQ= Subject: Re: Ping x2 Re: [PATCH 1/2][RFC] #17645, fix slow DSO sorting behavior in dynamic loader To: cltang@codesourcery.com, GNU C Library References: <2dea2558-c711-eab5-3728-be4986b7aad5@mentor.com> <8588322f-6391-7d6a-6b2e-f2cc05419622@mentor.com> From: Carlos O'Donell Message-ID: <55008c83-b935-c1b0-1166-2df97d1715b6@redhat.com> Date: Thu, 31 Oct 2019 09:13:34 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <8588322f-6391-7d6a-6b2e-f2cc05419622@mentor.com> X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 10/8/19 2:22 AM, Chung-Lin Tang wrote: > Ping again. I have these applied and I'm putting this through testing. > On 2019/9/17 5:55 PM, Chung-Lin Tang wrote: >> Ping? >> >> On 2019/7/21 1:50 AM, Chung-Lin Tang wrote: >>> Hi, this patch is our attempt at resolving the slow shared object sorti= ng >>> situation in #17645, #15310, and some effort at #15311.=C2=A0 I realize= this is >>> pretty unsuitable timing to be submitting a patch of such nature now (p= robably >>> way too late to be included into 2.30), but still sending now anyways a= s this >>> will probably need quite some discussion before being approved. >>> >>> Prior attempts at solving this slow sorting behavior appeared to have f= ailed >>> due to inadequate proposed testing, therefore cannot convince reviewers= to >>> touch what seems to be perceived as a sensitive and easy to break part = of ld.so. >>> >>> Therefore the first part of this patch is not a change to the dynamic l= oader >>> code proper, but a testing framework for constructing DSO sorting tests= . >>> It consists of a new Python script 'dso-ordering-test.py' that serves t= o >>> generate both testcase source files and the needed Makefile fragments f= rom >>> a short description string, for example: >>> >>> =C2=A0=C2=A0=C2=A0=C2=A0 a->b->c->d=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0 // four objects linked one after another >>> >>> =C2=A0=C2=A0=C2=A0=C2=A0 a->[bc]->d;b->c=C2=A0=C2=A0=C2=A0=C2=A0 // a d= epends on b and c, which both depend on d, >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= // b depends on c (b,c linked to object a in fixed order) >>> >>> =C2=A0=C2=A0=C2=A0=C2=A0 a->b->c;{+a;%a;-a}=C2=A0 // a, b, c serially d= ependent, main program uses >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= // dlopen/dlsym/dlclose on object a >>> >>> =C2=A0=C2=A0=C2=A0=C2=A0 a->b->c;{}!->[abc]=C2=A0 // a, b, c serially d= ependent; multiple tests generated >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= // to test all permutations of a, b, c ordering linked >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= // to main program >>> >>> =C2=A0=C2=A0=C2=A0 (Above is just a short description of what the scrip= t can do, more >>> =C2=A0=C2=A0=C2=A0=C2=A0 documentation is in the script comments.) >>> >>> and, a patch to glibc/elf/Makefile which uses this script to add a few >>> DSO sorting testcases.=C2=A0 The description string notation and output= form of the >>> generated testcases is short enough that both the test descriptions >>> and expected outcomes can all directly be specified in the Makefile. >>> >>> In terms of the tests I added using this script, I am not completely su= re they are >>> (together with existing tests) adequate to prove algorithmic integrity = in face >>> of any ld.so code changes, but the script should provide a solid tool t= o further >>> improve on coverage.=C2=A0 Also welcome suggestions if the current feat= ures are still >>> lacking in expressing some case of shared object relations, or if the d= ocumentation >>> still feels unclear. >>> >>> Thanks, >>> Chung-Lin >>> >>> 2019-07-20=C2=A0 Chung-Lin Tang=C2=A0 >>> >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 [BZ #17645] >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 [BZ #15311] >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 [BZ #15310] >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * elf/Makefile (test_d= so_ordering): New make function. >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 (tst-dso-ordering[1234= 56789]): Define new DSO sorting tests. >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 (tst-bz15311): Testcas= e from #15311. >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * scripts/dso-ordering= -test.py: New script. --=20 Cheers, Carlos.