From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincenzo Frascino Subject: Re: [PATCHv8 02/34] lib/vdso: make do_hres and do_coarse as __always_inline Date: Fri, 10 Jan 2020 11:47:43 +0000 Message-ID: References: <20191112012724.250792-1-dima@arista.com> <20191112012724.250792-3-dima@arista.com> <878smfa66i.fsf@nanos.tec.linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <878smfa66i.fsf-ecDvlHI5BZPZikZi3RtOZ1XZhhPuCNm+@public.gmane.org> Content-Language: en-US Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thomas Gleixner , Dmitry Safonov , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Dmitry Safonov <0x7f454c46-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Andrei Vagin , Adrian Reber , Andrei Vagin , Andy Lutomirski , Arnd Bergmann , Christian Brauner , Cyrill Gorcunov , "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jeff Dike , Oleg Nesterov , Pavel Emelyanov , Shuah Khan , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, criu-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org List-Id: linux-api@vger.kernel.org On 1/10/20 11:42 AM, Thomas Gleixner wrote: > Vincenzo Frascino writes: >> On 11/12/19 1:26 AM, Dmitry Safonov wrote: >>> +» » vd·=·&vd[CS_HRES_COARSE]; >>> +out_hres: >>> +» » return·do_hres(vd,·clock,·ts); >>> » }·else·if·(msk·&·VDSO_COARSE)·{ >>> » » do_coarse(&vd[CS_HRES_COARSE],·clock,·ts); >>> » » return·0; >>> » }·else·if·(msk·&·VDSO_RAW)·{ >>> -» » return·do_hres(&vd[CS_RAW],·clock,·ts); >>> +» » vd·=·&vd[CS_RAW]; >>> +» » /*·goto·allows·to·avoid·extra·inlining·of·do_hres.·*/ >>> +» » goto·out_hres; >> >> What is the performance impact of "goto out_hres"? > > On x86 it's invisible at least in my limited testing. On arm64 as well based on mine as well. Shall we keep the code more readable here (without goto)? > > Thanks, > > tglx > -- Regards, Vincenzo