Date: Fri, 6 Jul 2018 14:32:19 -0700 From: John Baldwin <jhb@FreeBSD.org> To: Matt Macy <mmacy@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r336020 - in head/sys: amd64/include arm/include arm64/include i386/include kern mips/include powerpc/include riscv/include sparc64/include sys vm x86/acpica Message-ID: <2c818e79-bcce-670c-9521-c4d171c3f5b1@FreeBSD.org> In-Reply-To: <201807060206.w662636M035282@repo.freebsd.org> References: <201807060206.w662636M035282@repo.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On 7/5/18 7:06 PM, Matt Macy wrote: > Author: mmacy > Date: Fri Jul 6 02:06:03 2018 > New Revision: 336020 > URL: https://svnweb.freebsd.org/changeset/base/336020 > > Log: > Back pcpu zone with domain correct pages > > - Change pcpu zone consumers to use a stride size of PAGE_SIZE. > (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) > > - Allocate page from the correct domain for a given cpu. > > - Don't initialize pc_domain to non-zero value if NUMA is not defined > There are some misconceptions surrounding this field. It is the > _VM_ NUMA domain and should only ever correspond to valid domain > values as understood by the VM. > > The former slab size of sizeof(struct pcpu) was somewhat arbitrary. > The new value is PAGE_SIZE because that's the smallest granularity > which the VM can allocate a slab for a given domain. If you have > fewer than PAGE_SIZE/8 counters on your system there will be some > memory wasted, but this is obviously something where you want the > cache line to be coming from the correct domain. > > Reviewed by: jeff > Sponsored by: Limelight Networks > Differential Revision: https://reviews.freebsd.org/D15933 So one thing about this change that confused me abit is why any of srat.c is being run at all in a non-NUMA kernel. When we reworked the NUMA options in HEAD to merge DEVICE_NUMA and VM_NUMA_ALLOC or whatever it was called into a single NUMA, my impression is that srat.c should be 'optional numa' in sys/conf/files.*. Is it just oversight that that wasn't done earlier, and should we in fact do that now? -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?2c818e79-bcce-670c-9521-c4d171c3f5b1>