Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) client-ip=2620:137:e000::3:5;
MIME-Version: 1.0
References: <CAK7LNARd_pRWWso49C4MoahFAM9idyOFC+9ZFYdpS87CA4UTqQ@mail.gmail.com>
 <20230926124044.3522663-1-jbrennen@google.com>
In-Reply-To: <20230926124044.3522663-1-jbrennen@google.com>
From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Tue, 3 Oct 2023 20:35:28 +0900
Message-ID: <CAK7LNARbPoTVG83kuHzD1mkwWn5Rqth1iYhfXbnsrk2LOvyHYg@mail.gmail.com>
Subject: Re: [PATCH] modpost: Optimize symbol search from linear to binary search
To:     Jack Brennen <jbrennen@google.com>
Cc:     Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>, Tom Rix <trix@redhat.com>,
        linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
        llvm@lists.linux.dev, maskray@google.com, cleger@rivosinc.com,
        kernel-team@android.com, joe@perches.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Tue, Sep 26, 2023 at 9:40=E2=80=AFPM Jack Brennen <jbrennen@google.com> =
wrote:
>
> Modify modpost to use binary search for converting addresses back
> into symbol references.  Previously it used linear search.
>
> This change saves a few seconds of wall time for defconfig builds,
> but can save several minutes on allyesconfigs.
>
> Before:
> $ make LLVM=3D1 -j128 allyesconfig vmlinux -s KCFLAGS=3D"-Wno-error"
> $ time scripts/mod/modpost -M -m -a -N -o vmlinux.symvers vmlinux.o
> 198.38user 1.27system 3:19.71elapsed
>
> After:
> $ make LLVM=3D1 -j128 allyesconfig vmlinux -s KCFLAGS=3D"-Wno-error"
> $ time scripts/mod/modpost -M -m -a -N -o vmlinux.symvers vmlinux.o
> 11.91user 0.85system 0:12.78elapsed
>
> Signed-off-by: Jack Brennen <jbrennen@google.com>
> Tested-by: Nick Desaulniers <ndesaulniers@google.com>


Applied to linux-kbuild.
Thanks.


--=20
Best Regards
Masahiro Yamada