Re: SCHED_ULE should not be the default

From: Jeremy Chadwick <freebsd_at_jdc.parodius.com>
Date: Mon, 12 Dec 2011 23:36:15 -0800
On Mon, Dec 12, 2011 at 02:47:57PM +0100, O. Hartmann wrote:
> > Not fully right, boinc defaults to run on idprio 31 so this isn't an
> > issue. And yes, there are cases where SCHED_ULE shows much better
> > performance then SCHED_4BSD.  [...]
> 
> Do we have any proof at hand for such cases where SCHED_ULE performs
> much better than SCHED_4BSD? Whenever the subject comes up, it is
> mentioned, that SCHED_ULE has better performance on boxes with a ncpu >
> 2. But in the end I see here contradictionary statements. People
> complain about poor performance (especially in scientific environments),
> and other give contra not being the case.
> 
> Within our department, we developed a highly scalable code for planetary
> science purposes on imagery. It utilizes present GPUs via OpenCL if
> present. Otherwise it grabs as many cores as it can.
> By the end of this year I'll get a new desktop box based on Intels new
> Sandy Bridge-E architecture with plenty of memory. If the colleague who
> developed the code is willing performing some benchmarks on the same
> hardware platform, we'll benchmark bot FreeBSD 9.0/10.0 and the most
> recent Suse. For FreeBSD I intent also to look for performance with both
> different schedulers available.

This is in no way shape or form the same kind of benchmark as what
you're planning to do, but I thought I'd throw it out there for folks to
take in as they see fit.

I know folks were focused mainly on buildworld.

I personally would find it interesting if someone with a higher-end
system (e.g. 2 physical CPUs, with 6 or 8 cores per CPU) was to do the
same test (changing -jX to -j{numofcores} of course).

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                   Mountain View, CA, US |
| Making life hard for others since 1977.               PGP 4BD6C0CB |


sched_ule
===========
- time make -j2 buildworld
  1689.831u 229.328s 18:46.20 170.4% 6566+2051k 432+4264io 4565pf+0w
- time make -j2 buildkernel
  640.542u 87.737s 9:01.38 134.5% 6490+1920k 134+5968io 0pf+0w


sched_4bsd
============
- time make -j2 buildworld
  1662.793u 206.908s 17:12.02 181.1% 6578+2054k 23750+4271io 6451pf+0w
- time make -j2 buildkernel
  638.717u 76.146s 8:34.90 138.8% 6530+1927k 6415+5903io 0pf+0w


software
==========
* sched_ule test:  FreeBSD 8.2-STABLE, Thu Dec  1 04:37:29 PST 2011
* sched_4bsd test: FreeBSD 8.2-STABLE, Mon Dec 12 22:42:54 PST 2011


hardware
==========
* Intel Core 2 Duo E8400, 3GHz
* Supermicro X7SBA
* 8GB ECC RAM (4x2GB), DDR2-800
* Intel 320-series SSD, 80GB: /, swap, /var, /tmp, /usr


tuning adjustments / etc.
===========================
* Before each scheduler test, system was rebooted to ensure I/O cache
  and other whatnots were empty
* All filesystems stock UFS2 + SU (root is non-SU)
* All filesystems had tunefs -t enable applied to them
* powerd(8) in use, with two rc.conf variables (per CPU spec):

performance_cx_lowest="C2"
economy_cx_lowest="C2"

* loader.conf

kern.maxdsiz="2560M"
kern.dfldsiz="2560M"
kern.maxssiz="256M"
ahci_load="yes"
hint.p4tcc.0.disabled="1"
hint.acpi_throttle.0.disabled="1"
vfs.zfs.arc_max="5120M"

* make.conf

CPUTYPE?=core2

* src.conf

WITHOUT_INET6=true
WITHOUT_IPFILTER=true
WITHOUT_LIB32=true
WITHOUT_KERBEROS=true
WITHOUT_PAM_SUPPORT=true
WITHOUT_PROFILE=true
WITHOUT_SENDMAIL=true

* kernel configuration
  - note: between kernel builds, config was changed to either use
    SCHED_4BSD or SCHED_ULE respectively.

cpu             HAMMER
ident           GENERIC

makeoptions     DEBUG=-g                # Build kernel with gdb(1) debug symbols

options         SCHED_4BSD              # Classic BSD scheduler
#options        SCHED_ULE               # ULE scheduler
options         PREEMPTION              # Enable kernel thread preemption
options         INET                    # InterNETworking
options         FFS                     # Berkeley Fast Filesystem
options         SOFTUPDATES             # Enable FFS soft updates support
options         UFS_ACL                 # Support for access control lists
options         UFS_DIRHASH             # Improve performance on big directories
options         UFS_GJOURNAL            # Enable gjournal-based UFS journaling
options         MD_ROOT                 # MD is a potential root device
options         NFSCLIENT               # Network Filesystem Client
options         NFSSERVER               # Network Filesystem Server
options         NFSLOCKD                # Network Lock Manager
options         NFS_ROOT                # NFS usable as /, requires NFSCLIENT
options         MSDOSFS                 # MSDOS Filesystem
options         CD9660                  # ISO 9660 Filesystem
options         PROCFS                  # Process filesystem (requires PSEUDOFS)
options         PSEUDOFS                # Pseudo-filesystem framework
options         GEOM_PART_GPT           # GUID Partition Tables.
options         GEOM_LABEL              # Provides labelization
options         COMPAT_43TTY            # BSD 4.3 TTY compat (sgtty)
options         SCSI_DELAY=5000         # Delay (in ms) before probing SCSI
options         KTRACE                  # ktrace(1) support
options         STACK                   # stack(9) support
options         SYSVSHM                 # SYSV-style shared memory
options         SYSVMSG                 # SYSV-style message queues
options         SYSVSEM                 # SYSV-style semaphores
options         P1003_1B_SEMAPHORES     # POSIX-style semaphores
options         _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
options         PRINTF_BUFR_SIZE=128    # Prevent printf output being interspersed.
options         KBD_INSTALL_CDEV        # install a CDEV entry in /dev
options         HWPMC_HOOKS             # Necessary kernel hooks for hwpmc(4)
options         AUDIT                   # Security event auditing
options         MAC                     # TrustedBSD MAC Framework
options         FLOWTABLE               # per-cpu routing cache
#options        KDTRACE_FRAME           # Ensure frames are compiled in
#options        KDTRACE_HOOKS           # Kernel DTrace hooks
options         INCLUDE_CONFIG_FILE     # Include this file in kernel

# Make an SMP-capable kernel by default
options         SMP                     # Symmetric MultiProcessor Kernel

# Debugging options
options         BREAK_TO_DEBUGGER       # Sending a serial BREAK drops to DDB
options         ALT_BREAK_TO_DEBUGGER   # Permit <CR>~<Ctrl-b> to drop to DDB
options         KDB                     # Enable kernel debugger support
options         KDB_TRACE               # Print stack trace automatically on panic
options         DDB                     # Support DDB
options         DDB_NUMSYM              # Print numeric value of symbols
options         GDB                     # Support remote GDB

# CPU frequency control
device          cpufreq

# Bus support.
device          acpi
device          pci

# Floppy drives
device          fdc

# ATA and ATAPI devices
# NOTE: "device ata" is missing because we use the Modular ATA core
# to only include the ATA-related drivers we need (e.g. AHCI).
device          atadisk         # ATA disk drives
device          ataraid         # ATA RAID drives
device          atapicd         # ATAPI CDROM drives
options         ATA_STATIC_ID   # Static device numbering

# Modular ATA
device          atacore         # Core ATA functionality
device          ataisa          # ISA bus support
device          atapci          # PCI bus support; only generic chipset support
device          ataahci         # AHCI SATA
device          ataintel        # Intel

# SCSI peripherals
device          scbus           # SCSI bus (required for SCSI)
device          da              # Direct Access (disks)
device          cd              # CD
device          pass            # Passthrough device (direct SCSI access)
device          ses             # SCSI Environmental Services (and SAF-TE)
options         CAMDEBUG        # CAM debugging (camcontrol debug)

# atkbdc0 controls both the keyboard and the PS/2 mouse
device          atkbdc          # AT keyboard controller
device          atkbd           # AT keyboard
device          psm             # PS/2 mouse

device          kbdmux          # keyboard multiplexer

device          vga             # VGA video card driver

device          splash          # Splash screen and screen saver support

# syscons is the default console driver, resembling an SCO console
device          sc

device          agp             # support several AGP chipsets

# Serial (COM) ports
device          uart            # Generic UART driver

# PCI Ethernet NICs.
device          em              # Intel PRO/1000 Gigabit Ethernet Family

# Wireless NIC cards
device          wlan            # 802.11 support
options         IEEE80211_DEBUG # enable debug msgs
options         IEEE80211_AMPDU_AGE     # age frames in AMPDU reorder q's
device          wlan_wep        # 802.11 WEP support
device          wlan_ccmp       # 802.11 CCMP support
device          wlan_tkip       # 802.11 TKIP support
device          wlan_amrr       # AMRR transmit rate control algorithm
device          wlan_acl        # MAC Access Control List support

# Pseudo devices.
device          loop            # Network loopback
device          random          # Entropy device
device          ether           # Ethernet support
device          pty             # BSD-style compatibility pseudo ttys
device          md              # Memory "disks"
device          gif             # IPv6 and IPv4 tunneling
device          faith           # IPv6-to-IPv4 relaying (translation)
device          firmware        # firmware assist module

# The `bpf' device enables the Berkeley Packet Filter.
# Be aware of the administrative consequences of enabling this!
# Note that 'bpf' is required for DHCP.
device          bpf             # Berkeley packet filter

# USB support
device          uhci            # UHCI PCI->USB interface
device          ohci            # OHCI PCI->USB interface
device          ehci            # EHCI PCI->USB interface (USB 2.0)
device          usb             # USB Bus (required)
#device         udbp            # USB Double Bulk Pipe devices
device          uhid            # "Human Interface Devices"
device          ukbd            # Keyboard
device          umass           # Disks/Mass storage - Requires scbus and da
device          ums             # Mouse

# Intel Core/Core2Duo CPU temperature monitoring driver
device          coretemp

# SMBus support, needed for bsdhwmon
device          smbus
device          smb
device          ichsmb

# Intel ICH hardware watchdog support
device          ichwd

# pf ALTQ support
options         ALTQ
options         ALTQ_CBQ        # Class Bases Queueing
options         ALTQ_RED        # Random Early Detection
options         ALTQ_RIO        # RED In/Out
options         ALTQ_HFSC       # Hierarchical Packet Scheduler
options         ALTQ_CDNR       # Traffic conditioner
options         ALTQ_PRIQ       # Priority Queueing
options         ALTQ_NOPCC      # Required for SMP build
Received on Tue Dec 13 2011 - 06:36:18 UTC

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