From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vs1-xe29.google.com (mail-vs1-xe29.google.com [IPv6:2607:f8b0:4864:20::e29]) by sourceware.org (Postfix) with ESMTPS id 3C0D13858D28; Wed, 27 Apr 2022 23:57:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3C0D13858D28 Received: by mail-vs1-xe29.google.com with SMTP id c62so3154878vsc.10; Wed, 27 Apr 2022 16:57:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WK1UyPz2YtVu2f1CI6JySwZL6+t4whXtyLyXJvl/V6M=; b=jifYY+7rv10i+nwfqPnGzudOOKIhzblEn8AdXs+8zRHqwR85BlNf7k7XKn8ilwkFUX VH7HPgbD0wokD4qcDNQbn7rjEUrwXFndIwfuNPZB/hIdb8LGfsDdYA/jZ4LDbiZKZQsK zA+PCmrzj08/biD8+q0WUJB9mJwCLo9VfF9EHgO8V3wjEd1w1k0czDhZcb4fMWo0h2Dw 4bACid9Ci/4m6POIGmHcOaATtfTLS9jocaPr5HH4tIlfe7oYx97xCiYA3mUKoCfkYIhu rF1hPIZVppLSKVtT2G4OjdIqpFrpSHKTaUGhhD5+kS+a0BO2zMJz9d63Azc46Az+6E2/ w4qQ== X-Gm-Message-State: AOAM530F3JzF72ZldzcBGRRwqaD/ArriHyOIIfhF21masrRKDGFTIqlm EXM+MPkP1RU0NNUyYLHDV4yRO2z2U/fwe01lLZ8KwE/OY4o= X-Google-Smtp-Source: ABdhPJzUHYdqgjgRLw0qw1Dru88i0G9g9MQJ4DZ0L2AN4tH/QjyE0v4hG9ucPzXuN48i10qVO93fRMFsYHifZfRGgkI= X-Received: by 2002:a05:6102:3fa7:b0:32c:deed:f5a0 with SMTP id o39-20020a0561023fa700b0032cdeedf5a0mr4845580vsv.47.1651103830531; Wed, 27 Apr 2022 16:57:10 -0700 (PDT) MIME-Version: 1.0 References: <20210430182442.3612464-1-hjl.tools@gmail.com> In-Reply-To: From: Sunil Pandey Date: Wed, 27 Apr 2022 16:56:34 -0700 Message-ID: Subject: Re: [PATCH v2] x86: Set rep_movsb_threshold to 2112 on processors with FSRM To: Noah Goldstein , libc-stable@sourceware.org Cc: "H.J. Lu" , GNU C Library Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, HK_RANDOM_ENVFROM, HK_RANDOM_FROM, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no 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: Wed, 27 Apr 2022 23:57:13 -0000 On Sat, May 1, 2021 at 12:47 PM Noah Goldstein via Libc-alpha wrote: > > On Sat, May 1, 2021 at 10:09 AM H.J. Lu wrote: > > > > On Fri, Apr 30, 2021 at 6:26 PM H.J. Lu wrote: > > > > > > On Fri, Apr 30, 2021 at 5:17 PM Noah Goldstein wrote: > > > > > > > > On Fri, Apr 30, 2021 at 4:51 PM H.J. Lu wrote: > > > > > > > > > > On Fri, Apr 30, 2021 at 3:59 PM Noah Goldstein wrote: > > > > > > > > > > > > On Fri, Apr 30, 2021 at 4:43 PM H.J. Lu via Libc-alpha > > > > > > wrote: > > > > > > > > > > > > > > The glibc memcpy benchmark on Intel Core i7-1065G7 (Ice Lake) showed > > > > > > > that REP MOVSB became faster after 2112 bytes: > > > > > > > > > > > > > > Vector + REP MOVSB REP MOVSB > > > > > > > length=2112, align1=0, align2=0: 24.20 24.40 > > > > > > > length=2112, align1=1, align2=0: 26.07 23.13 > > > > > > > length=2112, align1=0, align2=1: 27.18 28.13 > > > > > > > length=2112, align1=1, align2=1: 26.23 25.16 > > > > > > > length=2176, align1=0, align2=0: 23.18 22.52 > > > > > > > length=2176, align1=2, align2=0: 25.45 22.52 > > > > > > > length=2176, align1=0, align2=2: 27.14 27.82 > > > > > > > length=2176, align1=2, align2=2: 22.73 25.56 > > > > > > > length=2240, align1=0, align2=0: 24.62 24.25 > > > > > > > length=2240, align1=3, align2=0: 29.77 27.15 > > > > > > > length=2240, align1=0, align2=3: 35.55 29.93 > > > > > > > length=2240, align1=3, align2=3: 34.49 25.15 > > > > > > > length=2304, align1=0, align2=0: 34.75 26.64 > > > > > > > length=2304, align1=4, align2=0: 32.09 22.63 > > > > > > > length=2304, align1=0, align2=4: 28.43 31.24 > > > > > > > > > > > > > > > > > > > Do you know what is happening at: > > > > > > length=2304, align1=0, align2=4: 28.43 31.24 > > > > > > > > > > > > Seems align2 > align1 gets worse for larger sizes as well. > > > > > > > > > > > > I.e from my Icelake (1 run): > > > > > > w/o > > > > > > Patch w/ Patch > > > > > > length=3648, align1=0, align2=25: 72.91 83.99 > > > > > > length=3712, align1=0, align2=26: 72.52 84.92 > > > > > > length=3776, align1=0, align2=27: 76.16 84.02 > > > > > > length=3840, align1=0, align2=28: 75.44 90.13 > > > > > > length=3904, align1=0, align2=29: 81.62 84.43 > > > > > > length=3968, align1=0, align2=30: 76.82 93.39 > > > > > > length=4032, align1=0, align2=31: 80.01 89.89 > > > > > > length=4096, align1=0, align2=32: 72.89 97.50 > > > > > > > > > > On Intel Core i7-1165G7 (Tiger Lake), I got > > > > > > > > Where the original numbers icl or tgl? But was just wondering > > > > > > Here are numbers on Core i7-1065G7 (Ice Lake): > > > > > > __memcpy_evex_unaligned_erms __memcpy_erms > > > length=2048, align1=0, align2=0: 21.51 22.52 > > > length=2048, align1=0, align2=0: 22.11 21.50 > > > length=2048, align1=0, align2=0: 21.96 22.10 > > > length=2048, align1=0, align2=0: 22.58 21.51 > > > length=2112, align1=0, align2=0: 24.20 24.40 > > > length=2112, align1=1, align2=0: 26.07 23.13 > > > length=2112, align1=0, align2=1: 27.18 28.13 > > > length=2112, align1=1, align2=1: 26.23 25.16 > > > length=2176, align1=0, align2=0: 23.18 22.52 > > > length=2176, align1=2, align2=0: 25.45 22.52 > > > length=2176, align1=0, align2=2: 27.14 35.82 > > > length=2176, align1=2, align2=2: 22.73 25.56 > > > length=2240, align1=0, align2=0: 24.62 24.25 > > > length=2240, align1=3, align2=0: 29.77 27.15 > > > length=2240, align1=0, align2=3: 35.55 29.93 > > > length=2240, align1=3, align2=3: 34.49 25.15 > > > length=2304, align1=0, align2=0: 34.75 26.64 > > > length=2304, align1=4, align2=0: 32.09 22.63 > > > length=2304, align1=0, align2=4: 28.43 31.24 > > > length=2304, align1=4, align2=4: 23.95 25.56 > > > length=2368, align1=0, align2=0: 25.57 24.34 > > > length=2368, align1=5, align2=0: 30.57 23.94 > > > length=2368, align1=0, align2=5: 31.29 31.24 > > > length=2368, align1=5, align2=5: 25.57 26.69 > > > length=2432, align1=0, align2=0: 25.16 23.77 > > > length=2432, align1=6, align2=0: 29.27 23.13 > > > length=2432, align1=0, align2=6: 30.40 33.77 > > > length=2432, align1=6, align2=6: 25.16 26.37 > > > length=2496, align1=0, align2=0: 26.85 24.34 > > > length=2496, align1=7, align2=0: 32.04 24.75 > > > length=2496, align1=0, align2=7: 32.70 33.06 > > > length=2496, align1=7, align2=7: 26.79 25.97 > > > length=2560, align1=0, align2=0: 61.84 23.53 > > > length=2560, align1=8, align2=0: 30.74 23.53 > > > length=2560, align1=0, align2=8: 33.35 35.44 > > > length=2560, align1=8, align2=8: 27.94 27.52 > > > length=2624, align1=0, align2=0: 27.60 24.75 > > > length=2624, align1=9, align2=0: 33.28 25.16 > > > length=2624, align1=0, align2=9: 34.14 34.48 > > > length=2624, align1=9, align2=9: 28.00 26.78 > > > length=2688, align1=0, align2=0: 38.94 24.61 > > > length=2688, align1=10, align2=0: 31.23 23.94 > > > length=2688, align1=0, align2=10: 33.89 37.11 > > > length=2688, align1=10, align2=10: 28.40 27.18 > > > length=2752, align1=0, align2=0: 36.17 25.56 > > > length=2752, align1=11, align2=0: 35.88 25.57 > > > length=2752, align1=0, align2=11: 35.40 36.11 > > > length=2752, align1=11, align2=11: 28.82 27.94 > > > length=2816, align1=0, align2=0: 33.78 24.54 > > > length=2816, align1=12, align2=0: 33.75 25.96 > > > length=2816, align1=0, align2=12: 34.24 37.73 > > > length=2816, align1=12, align2=12: 29.22 27.59 > > > length=2880, align1=0, align2=0: 39.76 25.97 > > > length=2880, align1=13, align2=0: 41.26 26.66 > > > length=2880, align1=0, align2=13: 40.72 37.73 > > > length=2880, align1=13, align2=13: 35.13 27.59 > > > length=2944, align1=0, align2=0: 32.09 24.75 > > > length=2944, align1=14, align2=0: 40.27 26.78 > > > length=2944, align1=0, align2=14: 45.59 39.55 > > > length=2944, align1=14, align2=14: 40.94 28.00 > > > length=3008, align1=0, align2=0: 42.17 25.97 > > > length=3008, align1=15, align2=0: 41.81 27.07 > > > length=3008, align1=0, align2=15: 42.67 39.35 > > > length=3008, align1=15, align2=15: 42.18 28.00 > > > length=3072, align1=0, align2=0: 34.71 25.16 > > > length=3072, align1=16, align2=0: 43.31 26.37 > > > length=3072, align1=0, align2=16: 43.41 40.98 > > > length=3072, align1=16, align2=16: 36.62 27.99 > > > length=3136, align1=0, align2=0: 45.75 26.78 > > > length=3136, align1=17, align2=0: 43.29 27.59 > > > length=3136, align1=0, align2=17: 44.44 41.16 > > > length=3136, align1=17, align2=17: 34.99 28.59 > > > length=3200, align1=0, align2=0: 43.12 25.16 > > > length=3200, align1=18, align2=0: 43.04 27.59 > > > length=3200, align1=0, align2=18: 45.08 42.59 > > > length=3200, align1=18, align2=18: 36.00 28.81 > > > length=3264, align1=0, align2=0: 43.01 27.48 > > > length=3264, align1=19, align2=0: 47.72 28.61 > > > length=3264, align1=0, align2=19: 47.00 42.60 > > > length=3264, align1=19, align2=19: 44.44 28.81 > > > length=3328, align1=0, align2=0: 35.50 25.75 > > > length=3328, align1=20, align2=0: 44.84 27.19 > > > length=3328, align1=0, align2=20: 46.38 44.41 > > > length=3328, align1=20, align2=20: 33.68 28.81 > > > length=3392, align1=0, align2=0: 43.82 27.18 > > > length=3392, align1=21, align2=0: 45.91 28.81 > > > length=3392, align1=0, align2=21: 47.61 43.06 > > > length=3392, align1=21, align2=21: 43.82 29.21 > > > length=3456, align1=0, align2=0: 43.83 26.64 > > > length=3456, align1=22, align2=0: 44.77 29.49 > > > length=3456, align1=0, align2=22: 47.57 46.01 > > > length=3456, align1=22, align2=22: 44.11 29.62 > > > length=3520, align1=0, align2=0: 45.04 27.99 > > > length=3520, align1=23, align2=0: 46.59 30.55 > > > length=3520, align1=0, align2=23: 50.58 44.80 > > > length=3520, align1=23, align2=23: 43.85 29.21 > > > length=3584, align1=0, align2=0: 45.04 26.88 > > > length=3584, align1=24, align2=0: 47.22 29.21 > > > length=3584, align1=0, align2=24: 50.12 47.47 > > > length=3584, align1=24, align2=24: 45.04 29.80 > > > length=3648, align1=0, align2=0: 47.13 28.40 > > > length=3648, align1=25, align2=0: 48.78 30.94 > > > length=3648, align1=0, align2=25: 49.25 61.42 > > > length=3648, align1=25, align2=25: 45.85 30.02 > > > length=3712, align1=0, align2=0: 47.24 27.19 > > > length=3712, align1=26, align2=0: 48.41 30.79 > > > length=3712, align1=0, align2=26: 49.65 51.57 > > > length=3712, align1=26, align2=26: 48.76 30.33 > > > length=3776, align1=0, align2=0: 47.35 34.61 > > > length=3776, align1=27, align2=0: 49.16 31.99 > > > length=3776, align1=0, align2=27: 52.06 49.38 > > > length=3776, align1=27, align2=27: 47.36 30.43 > > > length=3840, align1=0, align2=0: 49.70 28.35 > > > length=3840, align1=28, align2=0: 50.29 31.81 > > > length=3840, align1=0, align2=28: 51.15 50.71 > > > length=3840, align1=28, align2=28: 47.07 31.65 > > > length=3904, align1=0, align2=0: 48.28 29.21 > > > length=3904, align1=29, align2=0: 51.96 32.99 > > > length=3904, align1=0, align2=29: 53.24 50.71 > > > length=3904, align1=29, align2=29: 47.88 31.64 > > > length=3968, align1=0, align2=0: 47.89 29.19 > > > length=3968, align1=30, align2=0: 51.52 32.57 > > > length=3968, align1=0, align2=30: 54.03 52.33 > > > length=3968, align1=30, align2=30: 46.62 33.15 > > > length=4032, align1=0, align2=0: 49.77 29.62 > > > length=4032, align1=31, align2=0: 53.62 34.27 > > > length=4032, align1=0, align2=31: 56.44 52.33 > > > length=4032, align1=31, align2=31: 48.94 33.16 > > > length=4096, align1=0, align2=0: 49.37 29.21 > > > length=4096, align1=32, align2=0: 50.46 33.00 > > > length=4096, align1=0, align2=32: 49.31 55.14 > > > length=4096, align1=32, align2=32: 49.28 33.05 > > > > > > > if the align2 != 0, align1 = 0 case on Icelake warranted more investigation. > > > > That being said the change is a clear winner on Icelake as well > > > > for any other alignment schema. > > > > > > True, REP MOVSB is more efficient. > > > > > > > This is the v2 patch I am checking in next week. > > Sorry! LGTM. Change is a big net gain :) > > > > > Thanks. > > > > -- > > H.J. I would like to backport this patch to release branches. Any comments or objections? --Sunil