From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by sourceware.org (Postfix) with ESMTPS id BBDC83858018 for ; Tue, 24 Aug 2021 15:19:46 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BBDC83858018 Received: by mail-pj1-x1029.google.com with SMTP id oc2-20020a17090b1c0200b00179e56772d6so1999220pjb.4 for ; Tue, 24 Aug 2021 08:19:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=q51b7Lcx31tIvCbjAC+5pE0unOb6XZzWlHlCVYQPh9U=; b=hRXLfb0sxY0Gj2iU8WPvmNIjY/7Ov1oYYNiLB6uK60x9zQMLsiq/Q7OEKXX5ZrvCDa ux4yaO/JifvABGKk7yzsu4bd3KaoR9wS4zSjP1gWmGX2qU9Go8oay4Ibdoz8AMvL/XKE vrGdmHdouIhMiEf3EHRv9ohD4YMyEn58Coq3JsdUbSUgOejYHZ7D1+SdpGQzw/6y9J2V 9nusUJRuX2YyeUaewkot7slPn/LYrlXLijYny8pEziHzbF4wdGI+nAXVHyR9EOL4HtLb f915/xRvEKn9PtgcR8QJXdXd2ArtnJmSafKU8qx/Qa4pYWNinOxFoZ9xhtICkPwOlbLX MKAw== X-Gm-Message-State: AOAM532nXKsVbThUb8M6XuJbjR9/6zbl/AOtQjAI/f09PrjXP0dNzXkU D++8N1DG/hUdBV9ZDqVCgG7jv2IPncMIctharBU= X-Google-Smtp-Source: ABdhPJy1/GkfePBh6UQfjzn72zxNeezgZWj0m9rBTWYjorU1OxMlGuQgrDvzceHj07EfNuIAAcEI5strjrc9SLZyanU= X-Received: by 2002:a17:90a:9cf:: with SMTP id 73mr5065639pjo.136.1629818385811; Tue, 24 Aug 2021 08:19:45 -0700 (PDT) MIME-Version: 1.0 References: <20210824082753.3356637-1-goldstein.w.n@gmail.com> <20210824082753.3356637-4-goldstein.w.n@gmail.com> In-Reply-To: <20210824082753.3356637-4-goldstein.w.n@gmail.com> From: "H.J. Lu" Date: Tue, 24 Aug 2021 08:19:09 -0700 Message-ID: Subject: Re: [PATCH 4/5] benchtests: Add additional cases to bench-memcpy.c and bench-memmove.c To: Noah Goldstein Cc: GNU C Library , "Carlos O'Donell" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3030.9 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Aug 2021 15:19:48 -0000 On Tue, Aug 24, 2021 at 1:28 AM Noah Goldstein wrote: > > This commit adds more benchmarks for the common memcpy/memmove > benchmarks. The most signifcant cases are the half page offsets. The > current versions leaves dst and src near page aligned which leads to > false 4k aliasing on x86_64. This can add noise due to false > dependencies from one run to the next. As well, this seems like more > of an edge case that common case so it shouldn't be the only thing > benchmarked. > --- > benchtests/bench-memcpy.c | 42 ++++++++++++++++++++++++++++++++++---- > benchtests/bench-memmove.c | 21 +++++++++++++++++-- > 2 files changed, 57 insertions(+), 6 deletions(-) > > diff --git a/benchtests/bench-memcpy.c b/benchtests/bench-memcpy.c > index d9236a2282..b9e661c997 100644 > --- a/benchtests/bench-memcpy.c > +++ b/benchtests/bench-memcpy.c > @@ -60,11 +60,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, > size_t i, j; > char *s1, *s2; > size_t repeats; > - align1 &= 63; > + align1 &= (getpagesize () - 1); > if (align1 + len >= page_size) > return; > > - align2 &= 63; > + align2 &= (getpagesize () - 1); > if (align2 + len >= page_size) > return; > > @@ -99,7 +99,7 @@ test_main (void) > { > json_ctx_t json_ctx; > size_t i; > - > + size_t half_page = getpagesize () / 2; > test_init (); > > json_init (&json_ctx, 0, stdout); > @@ -121,8 +121,15 @@ test_main (void) > { > do_test (&json_ctx, 0, 0, 1 << i, 1); > do_test (&json_ctx, i, 0, 1 << i, 1); > + do_test (&json_ctx, i + 32, 0, 1 << i, 1); > do_test (&json_ctx, 0, i, 1 << i, 1); > + do_test (&json_ctx, 0, i + 32, 1 << i, 1); > do_test (&json_ctx, i, i, 1 << i, 1); > + do_test (&json_ctx, i + 32, i + 32, 1 << i, 1); > + do_test (&json_ctx, half_page, 0, 1 << i, 1); > + do_test (&json_ctx, half_page + i, 0, 1 << i, 1); > + do_test (&json_ctx, half_page, i, 1 << i, 1); > + do_test (&json_ctx, half_page + i, i, 1 << i, 1); > } > > for (i = 0; i < 32; ++i) > @@ -131,6 +138,12 @@ test_main (void) > do_test (&json_ctx, i, 0, i, 0); > do_test (&json_ctx, 0, i, i, 0); > do_test (&json_ctx, i, i, i, 0); > + do_test (&json_ctx, half_page, 0, i, 0); > + do_test (&json_ctx, half_page + i, 0, i, 0); > + do_test (&json_ctx, half_page, i, i, 0); > + do_test (&json_ctx, half_page + i, i, i, 0); > + do_test (&json_ctx, getpagesize () - 1, 0, i, 0); > + do_test (&json_ctx, 0, getpagesize () - 1, i, 0); > } > > for (i = 3; i < 32; ++i) > @@ -141,6 +154,10 @@ test_main (void) > do_test (&json_ctx, i, 0, 16 * i, 1); > do_test (&json_ctx, 0, i, 16 * i, 1); > do_test (&json_ctx, i, i, 16 * i, 1); > + do_test (&json_ctx, half_page, 0, 16 * i, 1); > + do_test (&json_ctx, half_page + i, 0, 16 * i, 1); > + do_test (&json_ctx, half_page, i, 16 * i, 1); > + do_test (&json_ctx, half_page + i, i, 16 * i, 1); > } > > for (i = 32; i < 64; ++i) > @@ -149,16 +166,33 @@ test_main (void) > do_test (&json_ctx, i, 0, 32 * i, 1); > do_test (&json_ctx, 0, i, 32 * i, 1); > do_test (&json_ctx, i, i, 32 * i, 1); > + do_test (&json_ctx, half_page, 0, 32 * i, 1); > + do_test (&json_ctx, half_page + i, 0, 32 * i, 1); > + do_test (&json_ctx, half_page, i, 32 * i, 1); > + do_test (&json_ctx, half_page + i, i, 32 * i, 1); > } > > do_test (&json_ctx, 0, 0, getpagesize (), 1); > > - for (i = 0; i <= 32; ++i) > + for (i = 0; i <= 48; ++i) > { > do_test (&json_ctx, 0, 0, 2048 + 64 * i, 1); > do_test (&json_ctx, i, 0, 2048 + 64 * i, 1); > + do_test (&json_ctx, i + 32, 0, 2048 + 64 * i, 1); > do_test (&json_ctx, 0, i, 2048 + 64 * i, 1); > + do_test (&json_ctx, 0, i + 32, 2048 + 64 * i, 1); > do_test (&json_ctx, i, i, 2048 + 64 * i, 1); > + do_test (&json_ctx, i + 32, i + 32, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page, 0, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page + i, 0, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page, i, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page + i, i, 2048 + 64 * i, 1); > + do_test (&json_ctx, i, 1, 2048 + 64 * i, 1); > + do_test (&json_ctx, 1, i, 2048 + 64 * i, 1); > + do_test (&json_ctx, i + 32, 1, 2048 + 64 * i, 1); > + do_test (&json_ctx, 1, i + 32, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page + i, 1, 2048 + 64 * i, 1); > + do_test (&json_ctx, half_page + 1, i, 2048 + 64 * i, 1); > } > > json_array_end (&json_ctx); > diff --git a/benchtests/bench-memmove.c b/benchtests/bench-memmove.c > index 6becbf4782..bec1455f7b 100644 > --- a/benchtests/bench-memmove.c > +++ b/benchtests/bench-memmove.c > @@ -53,11 +53,11 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len) > size_t i, j; > char *s1, *s2; > > - align1 &= 63; > + align1 &= (getpagesize () - 1); > if (align1 + len >= page_size) > return; > > - align2 &= 63; > + align2 &= (getpagesize () - 1); > if (align2 + len >= page_size) > return; > > @@ -85,6 +85,7 @@ test_main (void) > { > json_ctx_t json_ctx; > size_t i; > + size_t half_page = getpagesize () / 2; > > test_init (); > > @@ -138,6 +139,22 @@ test_main (void) > do_test (&json_ctx, i, i, 32 * i); > } > > + for (i = 0; i <= 48; ++i) > + { > + do_test (&json_ctx, 0, 0, 2048 + 64 * i); > + do_test (&json_ctx, i, 0, 2048 + 64 * i); > + do_test (&json_ctx, 0, i, 2048 + 64 * i); > + do_test (&json_ctx, i, i, 2048 + 64 * i); > + do_test (&json_ctx, half_page, 0, 2048 + 64 * i); > + do_test (&json_ctx, 0, half_page, 2048 + 64 * i); > + do_test (&json_ctx, half_page + i, 0, 2048 + 64 * i); > + do_test (&json_ctx, i, half_page, 2048 + 64 * i); > + do_test (&json_ctx, half_page, i, 2048 + 64 * i); > + do_test (&json_ctx, 0, half_page + i, 2048 + 64 * i); > + do_test (&json_ctx, half_page + i, i, 2048 + 64 * i); > + do_test (&json_ctx, i, half_page + i, 2048 + 64 * i); > + } > + > json_array_end (&json_ctx); > json_attr_object_end (&json_ctx); > json_attr_object_end (&json_ctx); > -- > 2.25.1 > LGTM. Reviewed-by: H.J. Lu Thanks. -- H.J.