Date: Wed, 12 Feb 2020 09:26:08 -0800 From: Gleb Smirnoff <glebius@freebsd.org> To: Mateusz Guzik <mjg@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r357805 - head/sys/amd64/include Message-ID: <20200212172608.GD1253@FreeBSD.org> In-Reply-To: <202002121112.01CBCExs085630@repo.freebsd.org> References: <202002121112.01CBCExs085630@repo.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 12, 2020 at 11:12:14AM +0000, Mateusz Guzik wrote: M> Author: mjg M> Date: Wed Feb 12 11:12:13 2020 M> New Revision: 357805 M> URL: https://svnweb.freebsd.org/changeset/base/357805 M> M> Log: M> amd64: store per-cpu allocations subtracted by __pcpu M> M> This eliminates a runtime subtraction from counter_u64_add. M> M> before: M> mov 0x4f00ed(%rip),%rax # 0xffffffff80c01788 <numfullpathfail4> M> sub 0x808ff6(%rip),%rax # 0xffffffff80f1a698 <__pcpu> M> addq $0x1,%gs:(%rax) M> M> after: M> mov 0x4f02fd(%rip),%rax # 0xffffffff80c01788 <numfullpathfail4> M> addq $0x1,%gs:(%rax) M> M> Reviewed by: jeff M> Differential Revision: https://reviews.freebsd.org/D23570 Neat optimization! Thanks. Why didn't we do it back when created counter? -- Gleb Smirnoff
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20200212172608.GD1253>