I'm pretty sure that the "realmem" calculation is going to overflow on i386/PAE, where the number of bytes of physical memory is greater than the type long can represent.
On 11/27/2012 15:19, Andre Oppermann wrote: > Author: andre > Date: Tue Nov 27 21:19:58 2012 > New Revision: 243631 > URL: http://svnweb.freebsd.org/changeset/base/243631 > > Log: > Base the mbuf related limits on the available physical memory or > kernel memory, whichever is lower. The overall mbuf related memory > limit must be set so that mbufs (and clusters of various sizes) > can't exhaust physical RAM or KVM. > > The limit is set to half of the physical RAM or KVM (whichever is > lower) as the baseline. In any normal scenario we want to leave > at least half of the physmem/kvm for other kernel functions and > userspace to prevent it from swapping too easily. Via a tunable > kern.maxmbufmem the limit can be upped to at most 3/4 of physmem/kvm. > > At the same time divorce maxfiles from maxusers and set maxfiles to > physpages / 8 with a floor based on maxusers. This way busy servers > can make use of the significantly increased mbuf limits with a much > larger number of open sockets. > > Tidy up ordering in init_param2() and check up on some users of > those values calculated here. > > Out of the overall mbuf memory limit 2K clusters and 4K (page size) > clusters to get 1/4 each because these are the most heavily used mbuf > sizes. 2K clusters are used for MTU 1500 ethernet inbound packets. > 4K clusters are used whenever possible for sends on sockets and thus > outbound packets. The larger cluster sizes of 9K and 16K are limited > to 1/6 of the overall mbuf memory limit. When jumbo MTU's are used > these large clusters will end up only on the inbound path. They are > not used on outbound, there it's still 4K. Yes, that will stay that > way because otherwise we run into lots of complications in the > stack. And it really isn't a problem, so don't make a scene. > > Normal mbufs (256B) weren't limited at all previously. This was > problematic as there are certain places in the kernel that on > allocation failure of clusters try to piece together their packet > from smaller mbufs. > > The mbuf limit is the number of all other mbuf sizes together plus > some more to allow for standalone mbufs (ACK for example) and to > send off a copy of a cluster. Unfortunately there isn't a way to > set an overall limit for all mbuf memory together as UMA doesn't > support such a limiting. > > NB: Every cluster also has an mbuf associated with it. > > Two examples on the revised mbuf sizing limits: > > 1GB KVM: > 512MB limit for mbufs > 419,430 mbufs > 65,536 2K mbuf clusters > 32,768 4K mbuf clusters > 9,709 9K mbuf clusters > 5,461 16K mbuf clusters > > 16GB RAM: > 8GB limit for mbufs > 33,554,432 mbufs > 1,048,576 2K mbuf clusters > 524,288 4K mbuf clusters > 155,344 9K mbuf clusters > 87,381 16K mbuf clusters > > These defaults should be sufficient for even the most demanding > network loads. > > MFC after: 1 month > > Modified: > head/sys/kern/kern_mbuf.c > head/sys/kern/subr_param.c > head/sys/kern/uipc_socket.c > head/sys/sys/eventhandler.h > head/sys/sys/mbuf.h > > Modified: head/sys/kern/kern_mbuf.c > ============================================================================== > --- head/sys/kern/kern_mbuf.c Tue Nov 27 20:22:36 2012 (r243630) > +++ head/sys/kern/kern_mbuf.c Tue Nov 27 21:19:58 2012 (r243631) > @@ -96,6 +96,7 @@ __FBSDID("$FreeBSD$"); > * > */ > > +int nmbufs; /* limits number of mbufs */ > int nmbclusters; /* limits number of mbuf clusters */ > int nmbjumbop; /* limits number of page size jumbo > clusters */ > int nmbjumbo9; /* limits number of 9k jumbo clusters */ > @@ -147,9 +148,11 @@ sysctl_nmbclusters(SYSCTL_HANDLER_ARGS) > newnmbclusters = nmbclusters; > error = sysctl_handle_int(oidp, &newnmbclusters, 0, req); > if (error == 0 && req->newptr) { > - if (newnmbclusters > nmbclusters) { > + if (newnmbclusters > nmbclusters && > + nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) > { > nmbclusters = newnmbclusters; > uma_zone_set_max(zone_clust, nmbclusters); > + nmbclusters = uma_zone_get_max(zone_clust); > EVENTHANDLER_INVOKE(nmbclusters_change); > } else > error = EINVAL; > @@ -168,9 +171,11 @@ sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS) > newnmbjumbop = nmbjumbop; > error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req); > if (error == 0 && req->newptr) { > - if (newnmbjumbop> nmbjumbop) { > + if (newnmbjumbop > nmbjumbop && > + nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) > { > nmbjumbop = newnmbjumbop; > uma_zone_set_max(zone_jumbop, nmbjumbop); > + nmbjumbop = uma_zone_get_max(zone_jumbop); > } else > error = EINVAL; > } > @@ -189,9 +194,11 @@ sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS) > newnmbjumbo9 = nmbjumbo9; > error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req); > if (error == 0 && req->newptr) { > - if (newnmbjumbo9> nmbjumbo9) { > + if (newnmbjumbo9 > nmbjumbo9&& > + nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) > { > nmbjumbo9 = newnmbjumbo9; > uma_zone_set_max(zone_jumbo9, nmbjumbo9); > + nmbjumbo9 = uma_zone_get_max(zone_jumbo9); > } else > error = EINVAL; > } > @@ -209,9 +216,11 @@ sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS) > newnmbjumbo16 = nmbjumbo16; > error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req); > if (error == 0 && req->newptr) { > - if (newnmbjumbo16> nmbjumbo16) { > + if (newnmbjumbo16 > nmbjumbo16 && > + nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) > { > nmbjumbo16 = newnmbjumbo16; > uma_zone_set_max(zone_jumbo16, nmbjumbo16); > + nmbjumbo16 = uma_zone_get_max(zone_jumbo16); > } else > error = EINVAL; > } > @@ -221,6 +230,27 @@ SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumb > &nmbjumbo16, 0, sysctl_nmbjumbo16, "IU", > "Maximum number of mbuf 16k jumbo clusters allowed"); > > +static int > +sysctl_nmbufs(SYSCTL_HANDLER_ARGS) > +{ > + int error, newnmbufs; > + > + newnmbufs = nmbufs; > + error = sysctl_handle_int(oidp, &newnmbufs, 0, req); > + if (error == 0 && req->newptr) { > + if (newnmbufs > nmbufs) { > + nmbufs = newnmbufs; > + uma_zone_set_max(zone_mbuf, nmbufs); > + nmbclusters = uma_zone_get_max(zone_mbuf); > + EVENTHANDLER_INVOKE(nmbufs_change); > + } else > + error = EINVAL; > + } > + return (error); > +} > +SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbuf, CTLTYPE_INT|CTLFLAG_RW, > +&nmbufs, 0, sysctl_nmbufs, "IU", > + "Maximum number of mbufs allowed"); > > > SYSCTL_STRUCT(_kern_ipc, OID_AUTO, mbstat, CTLFLAG_RD, &mbstat, mbstat, > @@ -275,6 +305,10 @@ mbuf_init(void *dummy) > NULL, NULL, > #endif > MSIZE - 1, UMA_ZONE_MAXBUCKET); > + if (nmbufs > 0) { > + uma_zone_set_max(zone_mbuf, nmbufs); > + nmbufs = uma_zone_get_max(zone_mbuf); > + } > > zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES, > mb_ctor_clust, mb_dtor_clust, > @@ -284,8 +318,10 @@ mbuf_init(void *dummy) > NULL, NULL, > #endif > UMA_ALIGN_PTR, UMA_ZONE_REFCNT); > - if (nmbclusters > 0) > + if (nmbclusters > 0) { > uma_zone_set_max(zone_clust, nmbclusters); > + nmbclusters = uma_zone_get_max(zone_clust); > + } > > zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack, > mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf); > @@ -299,8 +335,10 @@ mbuf_init(void *dummy) > NULL, NULL, > #endif > UMA_ALIGN_PTR, UMA_ZONE_REFCNT); > - if (nmbjumbop > 0) > + if (nmbjumbop > 0) { > uma_zone_set_max(zone_jumbop, nmbjumbop); > + nmbjumbop = uma_zone_get_max(zone_jumbop); > + } > > zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES, > mb_ctor_clust, mb_dtor_clust, > @@ -310,9 +348,11 @@ mbuf_init(void *dummy) > NULL, NULL, > #endif > UMA_ALIGN_PTR, UMA_ZONE_REFCNT); > - if (nmbjumbo9 > 0) > - uma_zone_set_max(zone_jumbo9, nmbjumbo9); > uma_zone_set_allocf(zone_jumbo9, mbuf_jumbo_alloc); > + if (nmbjumbo9 > 0) { > + uma_zone_set_max(zone_jumbo9, nmbjumbo9); > + nmbjumbo9 = uma_zone_get_max(zone_jumbo9); > + } > > zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES, > mb_ctor_clust, mb_dtor_clust, > @@ -322,9 +362,11 @@ mbuf_init(void *dummy) > NULL, NULL, > #endif > UMA_ALIGN_PTR, UMA_ZONE_REFCNT); > - if (nmbjumbo16 > 0) > - uma_zone_set_max(zone_jumbo16, nmbjumbo16); > uma_zone_set_allocf(zone_jumbo16, mbuf_jumbo_alloc); > + if (nmbjumbo16 > 0) { > + uma_zone_set_max(zone_jumbo16, nmbjumbo16); > + nmbjumbo16 = uma_zone_get_max(zone_jumbo16); > + } > > zone_ext_refcnt = uma_zcreate(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), > NULL, NULL, > > Modified: head/sys/kern/subr_param.c > ============================================================================== > --- head/sys/kern/subr_param.c Tue Nov 27 20:22:36 2012 > (r243630) > +++ head/sys/kern/subr_param.c Tue Nov 27 21:19:58 2012 > (r243631) > @@ -93,6 +93,7 @@ int ncallout; /* maximum # of timer ev > int nbuf; > int ngroups_max; /* max # groups per process */ > int nswbuf; > +long maxmbufmem; /* max mbuf memory */ > pid_t pid_max = PID_MAX; > long maxswzone; /* max swmeta KVA storage */ > long maxbcache; /* max buffer cache KVA storage */ > @@ -270,6 +271,7 @@ init_param1(void) > void > init_param2(long physpages) > { > + long realmem; > > /* Base parameters */ > maxusers = MAXUSERS; > @@ -293,19 +295,25 @@ init_param2(long physpages) > /* > * The following can be overridden after boot via sysctl. Note: > * unless overriden, these macros are ultimately based on maxusers. > - */ > - maxproc = NPROC; > - TUNABLE_INT_FETCH("kern.maxproc", &maxproc); > - /* > * Limit maxproc so that kmap entries cannot be exhausted by > * processes. > */ > + maxproc = NPROC; > + TUNABLE_INT_FETCH("kern.maxproc", &maxproc); > if (maxproc > (physpages / 12)) > maxproc = physpages / 12; > - maxfiles = MAXFILES; > - TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); > maxprocperuid = (maxproc * 9) / 10; > - maxfilesperproc = (maxfiles * 9) / 10; > + > + /* > + * The default limit for maxfiles is 1/12 of the number of > + * physical page but not less than 16 times maxusers. > + * At most it can be 1/6 the number of physical pages. > + */ > + maxfiles = imax(MAXFILES, physpages / 8); > + TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); > + if (maxfiles > (physpages / 4)) > + maxfiles = physpages / 4; > + maxfilesperproc = (maxfiles / 10) * 9; > > /* > * Cannot be changed after boot. > @@ -313,20 +321,35 @@ init_param2(long physpages) > nbuf = NBUF; > TUNABLE_INT_FETCH("kern.nbuf", &nbuf); > > + /* > + * XXX: Does the callout wheel have to be so big? > + */ > ncallout = 16 + maxproc + maxfiles; > TUNABLE_INT_FETCH("kern.ncallout", &ncallout); > > /* > + * The default limit for all mbuf related memory is 1/2 of all > + * available kernel memory (physical or kmem). > + * At most it can be 3/4 of available kernel memory. > + */ > + realmem = lmin(physpages * PAGE_SIZE, > + VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS); > + maxmbufmem = realmem / 2; > + TUNABLE_LONG_FETCH("kern.maxmbufmem", &maxmbufmem); > + if (maxmbufmem > (realmem / 4) * 3) > + maxmbufmem = (realmem / 4) * 3; > + > + /* > * The default for maxpipekva is min(1/64 of the kernel address space, > * max(1/64 of main memory, 512KB)). See sys_pipe.c for more details. > */ > maxpipekva = (physpages / 64) * PAGE_SIZE; > + TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); > if (maxpipekva < 512 * 1024) > maxpipekva = 512 * 1024; > if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64) > maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / > 64; > - TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva); > } > > /* > > Modified: head/sys/kern/uipc_socket.c > ============================================================================== > --- head/sys/kern/uipc_socket.c Tue Nov 27 20:22:36 2012 > (r243630) > +++ head/sys/kern/uipc_socket.c Tue Nov 27 21:19:58 2012 > (r243631) > @@ -290,7 +290,7 @@ init_maxsockets(void *ignored) > { > > TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets); > - maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters)); > + maxsockets = imax(maxsockets, maxfiles); > } > SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL); > > @@ -306,12 +306,9 @@ sysctl_maxsockets(SYSCTL_HANDLER_ARGS) > newmaxsockets = maxsockets; > error = sysctl_handle_int(oidp, &newmaxsockets, 0, req); > if (error == 0 && req->newptr) { > - if (newmaxsockets > maxsockets) { > + if (newmaxsockets > maxsockets && > + newmaxsockets <= maxfiles) { > maxsockets = newmaxsockets; > - if (maxsockets > ((maxfiles / 4) * 3)) { > - maxfiles = (maxsockets * 5) / 4; > - maxfilesperproc = (maxfiles * 9) / 10; > - } > EVENTHANDLER_INVOKE(maxsockets_change); > } else > error = EINVAL; > > Modified: head/sys/sys/eventhandler.h > ============================================================================== > --- head/sys/sys/eventhandler.h Tue Nov 27 20:22:36 2012 > (r243630) > +++ head/sys/sys/eventhandler.h Tue Nov 27 21:19:58 2012 > (r243631) > @@ -253,6 +253,7 @@ EVENTHANDLER_DECLARE(thread_fini, thread > > typedef void (*uma_zone_chfn)(void *); > EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn); > +EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn); > EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn); > > #endif /* SYS_EVENTHANDLER_H */ > > Modified: head/sys/sys/mbuf.h > ============================================================================== > --- head/sys/sys/mbuf.h Tue Nov 27 20:22:36 2012 (r243630) > +++ head/sys/sys/mbuf.h Tue Nov 27 21:19:58 2012 (r243631) > @@ -395,7 +395,7 @@ struct mbstat { > * > * The rest of it is defined in kern/kern_mbuf.c > */ > - > +extern long maxmbufmem; > extern uma_zone_t zone_mbuf; > extern uma_zone_t zone_clust; > extern uma_zone_t zone_pack; > _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
