Date: Wed, 27 Jul 2011 08:45:39 -0400 From: John Baldwin <jhb@freebsd.org> To: Sergey Kandaurov <pluknet@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, Attilio Rao <attilio@freebsd.org>, Robert Watson <rwatson@freebsd.org>, Pan Tsu <inyaoo@gmail.com>, svn-src-head@freebsd.org, Sean Bruno <seanbru@yahoo-inc.com> Subject: Re: svn commit: r224217 - in head/sys: amd64/include ia64/include mips/conf sys Message-ID: <201107270845.39419.jhb@freebsd.org> In-Reply-To: <CAE-mSOLCoRR02pA5JDa=itZhtsDyBE5-sF7DjawPdg6zopn8fw@mail.gmail.com> References: <201107191300.p6JD0UU7073447@svn.freebsd.org> <201107210920.09604.jhb@freebsd.org> <CAE-mSOLCoRR02pA5JDa=itZhtsDyBE5-sF7DjawPdg6zopn8fw@mail.gmail.com>
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On Wednesday, July 27, 2011 2:24:21 am Sergey Kandaurov wrote: > On 21 July 2011 17:20, John Baldwin <jhb@freebsd.org> wrote: > > On Thursday, July 21, 2011 8:37:26 am Sergey Kandaurov wrote: > >> On 21 July 2011 14:14, Attilio Rao <attilio@freebsd.org> wrote: > >> > 2011/7/20 Pan Tsu <inyaoo@gmail.com>: > >> >> Attilio Rao <attilio@FreeBSD.org> writes: > >> >> > >> >>> Author: attilio > >> >>> Date: Tue Jul 19 13:00:30 2011 > >> >>> New Revision: 224217 > >> >>> URL: http://svn.freebsd.org/changeset/base/224217 > >> >>> > >> >>> Log: > >> >>> Bump MAXCPU for amd64, ia64 and XLP mips appropriately. > >> >>> From now on, default values for FreeBSD will be 64 maxiumum supported > >> >>> CPUs on amd64 and ia64 and 128 for XLP. All the other architectures > >> >>> seem already capped appropriately (with the exception of sparc64 which > >> >>> needs further support on jalapeno flavour). > >> >>> > >> >>> Bump __FreeBSD_version in order to reflect KBI/KPI brekage introduced > >> >>> during the infrastructure cleanup for supporting MAXCPU > 32. This > >> >>> covers cpumask_t retiral too. > >> >>> > >> >>> The switch is considered completed at the present time, so for > > whatever > >> >>> bug you may experience that is reconducible to that area, please > > report > >> >>> immediately. > >> >>> > >> >>> Requested by: marcel, jchandra > >> >>> Tested by: pluknet, sbruno > >> >>> Approved by: re (kib) > >> >>> > >> >>> Modified: > >> >>> head/sys/amd64/include/param.h > >> >>> head/sys/ia64/include/param.h > >> >>> head/sys/mips/conf/XLP > >> >>> head/sys/mips/conf/XLP64 > >> >>> head/sys/mips/conf/XLPN32 > >> >>> head/sys/sys/param.h > >> >>> > >> >>> Modified: head/sys/amd64/include/param.h > >> >>> > > ============================================================================== > >> >>> --- head/sys/amd64/include/param.h Tue Jul 19 12:41:57 2011 > > (r224216) > >> >>> +++ head/sys/amd64/include/param.h Tue Jul 19 13:00:30 2011 > > (r224217) > >> >>> @@ -65,7 +65,7 @@ > >> >>> > >> >>> #if defined(SMP) || defined(KLD_MODULE) > >> >>> #ifndef MAXCPU > >> >>> -#define MAXCPU 32 > >> >>> +#define MAXCPU 64 > >> >>> #endif > >> >>> #else > >> >>> #define MAXCPU 1 > >> >> > >> >> Do you plan to bump MEMSTAT_MAXCPU, too? > >> >> > >> >> $ vmstat -z > >> >> vmstat: memstat_sysctl_uma: Too many CPUs > >> >> $ vmstat -m > >> >> vmstat: memstat_sysctl_malloc: Too many CPUs > >> >> > >> >> $ sysctl kern. | grep smp.\*cpus > >> >> kern.smp.maxcpus: 64 > >> >> kern.smp.cpus: 2 > >> >> > >> > > >> > Jeeeez, we seriously need to fix this getting rid of the static values. > >> > > >> > Anyway, can you try the following patch?: > >> > http://www.freebsd.org/~attilio/memstat_maxcpu.diff > >> > > >> > It is going to add some memory overhead for i386 case. > >> > > >> > >> Something like this should work (vmstat -z, vmstat -m both work). > >> It gets rid of MEMSTAT_MAXCPU at the expense of malloc() at runtime. > >> http://plukky.net/~pluknet/patches/libmemstat_nomaxcpu.diff > >> > >> Probably it should work with maxid, instead of maxcpu to save some memory. > >> Though, using maxcpu is more safe. > > > > Actually, I would prefer that it use mp_maxid as that is the general variable > > things should use. mp_maxcpus is a concession for the few places that may > > need to know the MAXCPUS value (e.g. if using libkvm to access a structure in > > a crashdump or live kernel that has a member array with MAXCPU elements). > > Code that just wants to allocate memory to hold per-CPU data should use > > mp_maxid whenever possible. > > > > Hi, > > I changed the patch to use mp_maxid wherever possible. > http://plukky.net/~pluknet/patches/libmemstat_nomaxcpu.2.diff > > To summarize: > > 1) malloc stats > kern.malloc_stats uses internally MAXCPU, and we have to query MAXCPU > from kernel, too. See kern/kern_malloc.c:sysctl_kern_malloc_stats(): > 849 mtsh.mtsh_maxcpus = MAXCPU; > > 1a) memstat_sysctl_malloc() > left unchanged, sysctl kern.smp.maxcpus > 1b) memstat_kvm_malloc() > left unchanged, _mp_maxcpus symbol > > 2) uma stats > vm.zone_stats uses (mp_maxid + 1), vm/uma_core.c:sysctl_vm_zone_stats(): > 3247 ush.ush_maxcpus = (mp_maxid + 1); > > 2a) memstat_sysctl_uma() > Switched to query sysctl kern.smp.maxid > 2b) memstat_kvm_uma() > left unchanged, _mp_maxid symbol > > So, there's only one change in memstat_sysctl_uma(). > A bad side of things is that libmemstat() now knows these vm_zone > and malloc_stats internals. > As Robert suggested me on IRC to query maxcpu value from > uma_stream_header and malloc_type_stream_header structures > respectively to be independent from kernel details. Looks good to me, thanks! -- John Baldwin
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