Date: Mon, 20 Aug 2001 01:55:34 -0700 From: Peter Wemm <peter@wemm.org> To: Matt Dillon <dillon@earth.backplane.com> Cc: murray@FreeBSD.ORG, jkh@FreeBSD.ORG, hackers@FreeBSD.ORG, Leo Bicknell <bicknell@ufp.org> Subject: Re: Proposed patch (-stable) for minor KVM adjustments for the release Message-ID: <20010820085534.271B93905@overcee.netplex.com.au> In-Reply-To: <200108192046.f7JKkkA46377@earth.backplane.com>
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Murray/jkh, please do not approve this for MFC until the problems have been
fixed. For starters, it breaks all platforms other than the i386.
Matt Dillon wrote:
> Here is my proposed patch. It adds to options (overrides) to the kernel
> config, two boot-time tunables for same, and sets reasonable defaults.
> I also changed the default auto-sizing calculation for swap-meta from
> 32x physical pages to 16x physical pages on top of it being capped.
> I only made a small change there since we cannot really afford to run
> out of swap-meta structures (the system will probably lockup if we do).
>
> This patch is against -stable. I will commit it to -current today and
> await the release-engineers permission to MFC it to -stable for the
> release. I did some simple testing under -stable, including bumping up
> maxusers and NMBCLUSTERS.
>
> -Matt
>
> Index: conf/options
> ===================================================================
> RCS file: /home/ncvs/src/sys/conf/options,v
> retrieving revision 1.191.2.35
> diff -u -r1.191.2.35 options
> --- conf/options 2001/08/03 00:47:27 1.191.2.35
> +++ conf/options 2001/08/19 20:00:29
> @@ -163,6 +163,8 @@
> NBUF opt_param.h
> NMBCLUSTERS opt_param.h
> NSFBUFS opt_param.h
> +VM_BCACHE_SIZE_MAX opt_param.h
> +VM_SWZONE_SIZE_MAX opt_param.h
> MAXUSERS
>
> # Generic SCSI options.
> Index: i386/conf/LINT
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/conf/Attic/LINT,v
> retrieving revision 1.749.2.77
> diff -u -r1.749.2.77 LINT
> --- i386/conf/LINT 2001/08/15 01:23:49 1.749.2.77
> +++ i386/conf/LINT 2001/08/19 20:27:02
> @@ -2315,7 +2315,44 @@
> #
> options NSFBUFS=1024
>
> +# Set the size of the buffer cache KVM reservation, in buffers. This is
> +# scaled by approximately 16384 bytes. The system will auto-size the buffer
> +# cache if this option is not specified or set to 0.
> #
> +options NBUF=512
> +
> +# Set the size of the mbuf KVM reservation, in clusters. This is scaled
> +# by approximately 2048 bytes. The system will auto-size the mbuf area
> +# if this options is not specified or set to 0.
> +#
> +options NMBCLUSTERS=1024
> +
> +# Tune the kernel malloc area parameters. VM_KMEM_SIZE represents the
> +# minimum, in bytes, and is typically (12*1024*1024) (12MB).
> +# VM_KMEM_SIZE_MAX represents the maximum, typically 200 megabytes.
> +# VM_KMEM_SIZE_SCALE can be set to adjust the auto-tuning factor, which
> +# typically defaults to 4 (kernel malloc area size is physical memory
> +# divided by the scale factor).
> +#
> +options VM_KMEM_SIZE="(10*1024*1024)"
> +options VM_KMEM_SIZE_MAX="(100*1024*1024)"
> +options VM_KMEM_SIZE_SCALE="4"
> +
> +# Tune the buffer cache maximum KVA reservation, in bytes. The maximum is
> +# usually capped at 200 MB, effecting machines with > 1GB of ram. Note
> +# that the buffer cache only really governs write buffering and disk block
> +# translations. The VM page cache is our primary disk cache and is not
> +# effected by the size of the buffer cache.
> +#
> +options VM_BCACHE_SIZE_MAX="(100*1024*1024)"
> +
> +# Tune the swap zone KVA reservation, in bytes. The default is typically
> +# 70 MB, giving the system the ability to manage a maximum of 28GB worth
> +# of swapped out data.
> +#
> +options VM_SWZONE_SIZE_MAX="(50*1024*1024)"
> +
> +#
> # Enable extra debugging code for locks. This stores the filename and
> # line of whatever acquired the lock in the lock itself, and change a
> # number of function calls to pass around the relevant data. This is
> @@ -2500,9 +2537,7 @@
> options KEY
> options LOCKF_DEBUG
> options LOUTB
> -options NBUF=512
> options NETATALKDEBUG
> -options NMBCLUSTERS=1024
> #options OLTR_NO_BULLSEYE_MAC
> #options OLTR_NO_HAWKEYE_MAC
> #options OLTR_NO_TMS_MAC
> @@ -2521,7 +2556,5 @@
> options SPX_HACK
> options TIMER_FREQ="((14318182+6)/12)"
> options VFS_BIO_DEBUG
> -options VM_KMEM_SIZE
> -options VM_KMEM_SIZE_MAX
> -options VM_KMEM_SIZE_SCALE
> options XBONEHACK
> +
> Index: i386/i386/machdep.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/i386/machdep.c,v
> retrieving revision 1.385.2.15
> diff -u -r1.385.2.15 machdep.c
> --- i386/i386/machdep.c 2001/07/30 23:27:59 1.385.2.15
> +++ i386/i386/machdep.c 2001/08/19 20:36:19
> @@ -320,7 +320,9 @@
> * The nominal buffer size (and minimum KVA allocation) is BKVASIZE.
> * For the first 64MB of ram nominally allocate sufficient buffers to
> * cover 1/4 of our ram. Beyond the first 64MB allocate additional
> - * buffers to cover 1/20 of our ram over 64MB.
> + * buffers to cover 1/20 of our ram over 64MB. When auto-sizing
> + * the buffer cache we limit the eventual kva reservation to
> + * maxbcache bytes.
> *
> * factor represents the 1/4 x ram conversion.
> */
> @@ -332,6 +334,8 @@
> nbuf += min((physmem - 1024) / factor, 16384 / factor);
> if (physmem > 16384)
> nbuf += (physmem - 16384) * 2 / (factor * 5);
> + if (maxbcache && nbuf > maxbcache / BKVASIZE)
> + nbuf = maxbcache / BKVASIZE;
> }
>
> /*
> Index: i386/include/param.h
> ===================================================================
> RCS file: /home/ncvs/src/sys/i386/include/param.h,v
> retrieving revision 1.54.2.4
> diff -u -r1.54.2.4 param.h
> --- i386/include/param.h 2000/12/29 10:59:18 1.54.2.4
> +++ i386/include/param.h 2001/08/19 20:07:08
> @@ -113,6 +113,22 @@
> #define UPAGES 2 /* pages of u-area */
>
> /*
> + * Ceiling on amount of swblock kva space.
> + */
> +#ifndef VM_SWZONE_SIZE_MAX
> +#define VM_SWZONE_SIZE_MAX (70 * 1024 * 1024)
> +#endif
> +
> +/*
> + * Ceiling on size of buffer cache (really only effects write queueing,
> + * the VM page cache is not effected).
> + */
> +#ifndef VM_BCACHE_SIZE_MAX
> +#define VM_BCACHE_SIZE_MAX (200 * 1024 * 1024)
> +#endif
> +
> +
> +/*
> * Constants related to network buffer management.
> * MCLBYTES must be no larger than CLBYTES (the software page size), and,
> * on machines that exchange pages of input or output buffers with mbuf
> Index: kern/subr_param.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/kern/subr_param.c,v
> retrieving revision 1.42.2.1
> diff -u -r1.42.2.1 subr_param.c
> --- kern/subr_param.c 2001/07/30 23:28:00 1.42.2.1
> +++ kern/subr_param.c 2001/08/19 20:04:05
> @@ -76,6 +76,8 @@
> int mbuf_wait = 32; /* mbuf sleep time in ticks */
> int nbuf;
> int nswbuf;
> +int maxswzone; /* max swmeta KVA storage */
> +int maxbcache; /* max buffer cache KVA storage */
>
> /* maximum # of sf_bufs (sendfile(2) zero-copy virtual buffers) */
> int nsfbufs;
> @@ -115,6 +117,10 @@
> TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
> nbuf = NBUF;
> TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
> + maxswzone = VM_SWZONE_SIZE_MAX;
> + TUNABLE_INT_FETCH("kern.maxswzone", &maxswzone);
> + maxbcache = VM_BCACHE_SIZE_MAX;
> + TUNABLE_INT_FETCH("kern.maxbcache", &maxbcache);
> ncallout = 16 + maxproc + maxfiles;
> TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
> }
> Index: sys/buf.h
> ===================================================================
> RCS file: /home/ncvs/src/sys/sys/buf.h,v
> retrieving revision 1.88.2.4
> diff -u -r1.88.2.4 buf.h
> --- sys/buf.h 2001/06/03 05:00:10 1.88.2.4
> +++ sys/buf.h 2001/08/19 19:54:02
> @@ -455,6 +455,8 @@
>
> #ifdef _KERNEL
> extern int nbuf; /* The number of buffer headers */
> +extern int maxswzone; /* Max KVA for swap structures */
> +extern int maxbcache; /* Max KVA for buffer cache */
> extern int runningbufspace;
> extern int buf_maxio; /* nominal maximum I/O for buffer */
> extern struct buf *buf; /* The buffer headers. */
> Index: vm/swap_pager.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/vm/swap_pager.c,v
> retrieving revision 1.130.2.8
> diff -u -r1.130.2.8 swap_pager.c
> --- vm/swap_pager.c 2001/03/24 20:28:24 1.130.2.8
> +++ vm/swap_pager.c 2001/08/19 19:47:19
> @@ -300,10 +300,12 @@
> /*
> * Initialize our zone. Right now I'm just guessing on the number
> * we need based on the number of pages in the system. Each swblock
> - * can hold 16 pages, so this is probably overkill.
> + * can hold 16 pages, so this is probably overkill. This reservation
> + * is typically limited to around 70MB by default.
> */
> -
> - n = cnt.v_page_count * 2;
> + n = cnt.v_page_count;
> + if (maxswzone && n > maxswzone / sizeof(struct swblock))
> + n = maxswzone / sizeof(struct swblock);
>
> swap_zone = zinit(
> "SWAPMETA",
>
>
Cheers,
-Peter
--
Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au
"All of this is for nothing if we don't go to the stars" - JMS/B5
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