From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753950Ab0CYK2A (ORCPT ); Thu, 25 Mar 2010 06:28:00 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:62570 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753258Ab0CYK15 (ORCPT ); Thu, 25 Mar 2010 06:27:57 -0400 From: Arnd Bergmann To: Andrew Morton Subject: Re: [GIT, RFC] Killing the Big Kernel Lock Date: Thu, 25 Mar 2010 11:26:56 +0100 User-Agent: KMail/1.12.2 (Linux/2.6.31-19-generic; KDE/4.3.2; x86_64; ; ) Cc: Frederic Weisbecker , linux-kernel@vger.kernel.org, Matthew Wilcox , Thomas Gleixner , jblunck@suse.de, Alan Cox , Ingo Molnar References: <201003242240.54907.arnd@arndb.de> <20100324170704.7ef8b9c1.akpm@linux-foundation.org> In-Reply-To: <20100324170704.7ef8b9c1.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201003251126.56640.arnd@arndb.de> X-Provags-ID: V01U2FsdGVkX19FMOtn7oWlKktIsfxdgYdlBPDUQlMK+ltCxvN Lg1RYXSm4HWvQqKAGI5ixGLFXLQPYIR6PnPXU/EvutbFat6KF+ 9Pv3AmzVS8/QHBSHv/gBw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 24 March 2010, Andrew Morton wrote: > On Wed, 24 Mar 2010 22:40:54 +0100 Arnd Bergmann wrote: > > > I've spent some time continuing the work of the people on Cc and many others > > to remove the big kernel lock from Linux > > > > Seems that there might be a few tricksy bits in here. Please do push > at least the non-obvious parts out to the relevant people. Sure, that is certainly the plan. Regarding the ptrace bits, this is one of a handful of places where the BKL was put in by someone a really long time ago but with the rest of the series applied, it becomes evident that there is nothing whatsoever that it serializes with, so removing the BKL here does not make the situation worse. It could still be a bug that needs to be fixed by adding a new serialization method no matter if the BKL is there or not. > It'd be interesting to see the overall diffstat? Let me give you three separate diffstats. One is for the trivial pushdown of the BKL into all the ioctl and llseek functions as well as marking all remaining users as 'depends on BKL' in Kconfig, the second one is for the TTY layer conversion to the Big TTY Mutex and the third one is all the rest. Arnd --- Big TTY Mutex conversion: drivers/char/Makefile | 2 + drivers/char/amiserial.c | 16 ++-- drivers/char/cyclades.c | 20 ++-- drivers/char/epca.c | 4 +- drivers/char/isicom.c | 10 +- drivers/char/istallion.c | 20 ++-- drivers/char/mxser.c | 10 +- drivers/char/n_hdlc.c | 16 ++-- drivers/char/n_r3964.c | 10 +- drivers/char/pty.c | 8 +- drivers/char/riscom8.c | 8 +- drivers/char/rocket.c | 8 +- drivers/char/serial167.c | 4 +- drivers/char/specialix.c | 10 +- drivers/char/stallion.c | 12 ++-- drivers/char/sx.c | 12 ++-- drivers/char/synclink.c | 10 ++- drivers/char/synclink_gt.c | 8 +- drivers/char/synclinkmp.c | 12 ++-- drivers/char/tty_buffer.c | 2 +- drivers/char/tty_io.c | 123 +++++++++++++++------------ drivers/char/tty_ioctl.c | 36 ++++---- drivers/char/tty_ldisc.c | 53 +++++++----- drivers/char/tty_lock.c | 100 ++++++++++++++++++++++ drivers/char/tty_port.c | 6 +- drivers/char/vc_screen.c | 4 +- drivers/char/vt.c | 4 +- drivers/char/vt_ioctl.c | 12 ++-- drivers/isdn/i4l/isdn_common.c | 20 ++-- drivers/isdn/i4l/isdn_tty.c | 8 +- drivers/net/irda/irtty-sir.c | 5 +- drivers/net/ppp_generic.c | 29 +++--- drivers/serial/68360serial.c | 4 +- drivers/serial/crisv10.c | 8 +- drivers/serial/serial_core.c | 42 +++++----- drivers/staging/strip/strip.c | 2 +- drivers/usb/class/cdc-acm.c | 2 +- drivers/usb/serial/usb-serial.c | 18 ++-- drivers/video/console/vgacon.c | 4 +- include/linux/init_task.h | 1 + include/linux/sched.h | 1 + include/linux/tty.h | 180 +++++++++++++++++++++++++++++++++++++++ kernel/fork.c | 1 + ioctl/llseek pushdown, Kconfig: 43 files changed, 590 insertions(+), 275 deletions(-) Documentation/DocBook/kernel-hacking.tmpl | 2 +- Documentation/filesystems/vfs.txt | 3 +- arch/arm/kernel/etm.c | 1 - arch/cris/arch-v10/drivers/ds1302.c | 3 - arch/cris/arch-v10/drivers/gpio.c | 2 - arch/cris/arch-v10/drivers/i2c.c | 2 - arch/cris/arch-v10/drivers/pcf8563.c | 3 - arch/cris/arch-v10/drivers/sync_serial.c | 4 +- arch/cris/arch-v32/drivers/cryptocop.c | 4 +- arch/cris/arch-v32/drivers/i2c.c | 2 - arch/cris/arch-v32/drivers/mach-a3/gpio.c | 2 - arch/cris/arch-v32/drivers/mach-fs/gpio.c | 2 - arch/cris/arch-v32/drivers/pcf8563.c | 5 +- arch/cris/arch-v32/drivers/sync_serial.c | 4 +- arch/ia64/kernel/perfmon.c | 2 - arch/ia64/sn/kernel/sn2/sn_hwperf.c | 2 - arch/m68k/bvme6000/rtc.c | 2 - arch/m68k/mvme16x/rtc.c | 2 - arch/powerpc/platforms/iseries/Kconfig | 1 - arch/s390/Kconfig | 1 - arch/um/drivers/harddog_kern.c | 2 - arch/um/drivers/hostaudio_kern.c | 3 - arch/um/drivers/mmapper_kern.c | 3 - arch/x86/Kconfig | 3 +- arch/x86/kvm/Kconfig | 1 - drivers/block/DAC960.c | 3 +- drivers/block/Kconfig | 6 +- drivers/block/paride/pg.c | 2 - drivers/block/paride/pt.c | 2 - drivers/block/pktcdvd.c | 3 - drivers/char/Kconfig | 25 +- drivers/char/apm-emulation.c | 2 - drivers/char/applicom.c | 2 - drivers/char/ds1302.c | 1 - drivers/char/ds1620.c | 2 - drivers/char/dtlk.c | 2 - drivers/char/generic_nvram.c | 2 - drivers/char/genrtc.c | 2 - drivers/char/i8k.c | 2 - drivers/char/ip2/ip2main.c | 1 - drivers/char/ipmi/Kconfig | 2 - drivers/char/ipmi/ipmi_devintf.c | 2 - drivers/char/ipmi/ipmi_watchdog.c | 2 - drivers/char/istallion.c | 1 - drivers/char/lp.c | 1 - drivers/char/mmtimer.c | 1 - drivers/char/nwflash.c | 1 - drivers/char/pcmcia/Kconfig | 4 +- drivers/char/raw.c | 4 - drivers/char/rio/rio_linux.c | 1 - drivers/char/stallion.c | 1 - drivers/char/sx.c | 1 - drivers/char/uv_mmtimer.c | 1 - drivers/char/viotape.c | 1 - drivers/crypto/Kconfig | 2 +- drivers/firewire/Kconfig | 1 - drivers/firewire/core-cdev.c | 2 - drivers/gpu/drm/Kconfig | 5 +- drivers/gpu/drm/i810/i810_dma.c | 2 - drivers/gpu/drm/i830/i830_dma.c | 2 - drivers/hid/Kconfig | 2 +- drivers/hid/usbhid/Kconfig | 2 +- drivers/hid/usbhid/hiddev.c | 3 +- drivers/hwmon/Kconfig | 2 +- drivers/hwmon/fschmd.c | 2 - drivers/ide/Kconfig | 1 - drivers/ide/ide-tape.c | 1 - drivers/ieee1394/Kconfig | 6 +- drivers/ieee1394/dv1394.c | 2 - drivers/ieee1394/raw1394.c | 2 - drivers/ieee1394/video1394.c | 4 +- drivers/infiniband/Kconfig | 6 +- drivers/infiniband/core/ucm.c | 2 - drivers/infiniband/core/ucma.c | 2 - drivers/infiniband/core/user_mad.c | 3 - drivers/infiniband/core/uverbs_main.c | 11 +- drivers/input/joystick/Kconfig | 2 +- drivers/input/misc/Kconfig | 13 +- drivers/input/misc/hp_sdc_rtc.c | 2 - drivers/input/misc/uinput.c | 1 - drivers/input/mouse/Kconfig | 4 +- drivers/input/serio/Kconfig | 1 - drivers/input/tablet/Kconfig | 8 +- drivers/input/touchscreen/Kconfig | 2 +- drivers/isdn/Kconfig | 2 - drivers/isdn/capi/Kconfig | 2 +- drivers/isdn/capi/capi.c | 1 - drivers/isdn/divert/divert_procfs.c | 2 - drivers/isdn/hardware/eicon/Kconfig | 2 +- drivers/isdn/hysdn/Kconfig | 2 +- drivers/isdn/i4l/Kconfig | 1 - drivers/isdn/i4l/isdn_common.c | 1 - drivers/isdn/mISDN/Kconfig | 1 - drivers/isdn/mISDN/timerdev.c | 3 - drivers/macintosh/Kconfig | 7 +- drivers/macintosh/ans-lcd.c | 2 - drivers/macintosh/nvram.c | 2 - drivers/macintosh/via-pmu.c | 2 - drivers/media/Kconfig | 5 +- drivers/media/dvb/bt8xx/Kconfig | 2 +- drivers/media/dvb/bt8xx/dst_ca.c | 1 - drivers/media/dvb/dvb-core/dmxdev.c | 3 - drivers/media/dvb/dvb-core/dvb_ca_en50221.c | 3 - drivers/media/dvb/dvb-core/dvb_frontend.c | 5 +- drivers/media/dvb/dvb-core/dvb_net.c | 3 - drivers/media/dvb/firewire/Kconfig | 2 +- drivers/media/dvb/firewire/firedtv-ci.c | 3 - drivers/media/dvb/ttpci/Kconfig | 2 +- drivers/media/dvb/ttpci/av7110.c | 3 - drivers/media/dvb/ttpci/av7110_av.c | 5 - drivers/media/dvb/ttpci/av7110_ca.c | 3 - drivers/media/video/Kconfig | 13 +- drivers/media/video/cpia.c | 2 - drivers/media/video/v4l2-dev.c | 2 - drivers/message/fusion/Kconfig | 2 +- drivers/message/i2o/Kconfig | 2 +- drivers/misc/Kconfig | 2 +- drivers/mtd/Kconfig | 1 - drivers/mtd/mtdchar.c | 1 - drivers/mtd/ubi/Kconfig | 2 +- drivers/mtd/ubi/cdev.c | 2 - drivers/net/Kconfig | 1 - drivers/net/appletalk/Kconfig | 1 - drivers/net/ppp_generic.c | 4 +- drivers/net/wan/Kconfig | 2 +- drivers/net/wireless/Kconfig | 4 +- drivers/net/wireless/airo.c | 9 - drivers/net/wireless/ray_cs.c | 3 - drivers/pci/hotplug/Kconfig | 2 +- drivers/pcmcia/Kconfig | 3 +- drivers/platform/x86/Kconfig | 1 - drivers/pnp/isapnp/Kconfig | 2 +- drivers/rtc/Kconfig | 1 - drivers/rtc/rtc-m41t80.c | 1 - drivers/s390/block/Kconfig | 2 +- drivers/s390/char/Kconfig | 2 +- drivers/s390/char/fs3270.c | 1 - drivers/s390/char/tape_char.c | 2 +- drivers/s390/cio/chsc_sch.c | 2 - drivers/s390/crypto/zcrypt_api.c | 1 - drivers/s390/scsi/zfcp_cfdc.c | 2 - drivers/sbus/char/envctrl.c | 1 - drivers/sbus/char/openprom.c | 1 - drivers/scsi/3w-9xxx.c | 2 - drivers/scsi/3w-sas.c | 2 - drivers/scsi/3w-xxxx.c | 2 - drivers/scsi/Kconfig | 28 +- drivers/scsi/aacraid/linit.c | 1 - drivers/scsi/dpt_i2o.c | 2 - drivers/scsi/gdth.c | 2 - drivers/scsi/megaraid.c | 2 - drivers/scsi/megaraid/Kconfig.megaraid | 6 +- drivers/scsi/megaraid/megaraid_mm.c | 2 - drivers/scsi/megaraid/megaraid_sas.c | 1 - drivers/scsi/mpt2sas/Kconfig | 2 +- drivers/scsi/mpt2sas/mpt2sas_ctl.c | 1 - drivers/scsi/osd/Kconfig | 2 +- drivers/scsi/osd/osd_uld.c | 2 - drivers/scsi/osst.c | 2 - drivers/scsi/pmcraid.c | 2 - drivers/scsi/st.c | 1 - drivers/spi/spidev.c | 2 - drivers/staging/comedi/comedi_fops.c | 2 - drivers/staging/dream/pmem.c | 3 - drivers/staging/dream/qdsp5/audio_aac.c | 2 - drivers/staging/dream/qdsp5/audio_mp3.c | 2 - drivers/staging/poch/poch.c | 3 - drivers/staging/sep/sep_driver.c | 2 - drivers/staging/vme/devices/vme_user.c | 2 - drivers/telephony/Kconfig | 2 +- drivers/telephony/ixj.c | 1 - drivers/usb/Kconfig | 2 +- drivers/usb/class/Kconfig | 1 - drivers/usb/class/usblp.c | 2 - drivers/usb/gadget/Kconfig | 2 - drivers/usb/gadget/printer.c | 1 - drivers/usb/host/Kconfig | 2 +- drivers/usb/misc/Kconfig | 8 +- drivers/usb/misc/idmouse.c | 2 - drivers/usb/misc/iowarrior.c | 1 - drivers/usb/misc/rio500.c | 1 - drivers/usb/misc/sisusbvga/Kconfig | 2 +- fs/adfs/Kconfig | 1 - fs/afs/Kconfig | 1 - fs/autofs/Kconfig | 1 - fs/autofs/root.c | 1 - fs/autofs4/Kconfig | 1 - fs/autofs4/dev-ioctl.c | 2 - fs/btrfs/super.c | 1 - fs/coda/Kconfig | 1 - fs/coda/pioctl.c | 3 - fs/coda/psdev.c | 2 - fs/ecryptfs/Kconfig | 1 - fs/ecryptfs/file.c | 2 - fs/ecryptfs/miscdev.c | 2 - fs/fat/Kconfig | 3 - fs/freevxfs/Kconfig | 1 - fs/hfsplus/Kconfig | 1 - fs/hfsplus/dir.c | 2 - fs/hfsplus/inode.c | 2 - fs/hpfs/Kconfig | 1 - fs/ioctl.c | 11 +- fs/isofs/Kconfig | 1 - fs/jffs2/Kconfig | 1 - fs/ncpfs/Kconfig | 1 - fs/ncpfs/dir.c | 2 - fs/ncpfs/file.c | 1 - fs/nfs/Kconfig | 2 +- fs/nfsd/Kconfig | 1 - fs/ocfs2/Kconfig | 1 - fs/qnx4/Kconfig | 1 - fs/read_write.c | 34 + fs/reiserfs/Kconfig | 1 - fs/smbfs/Kconfig | 1 - fs/smbfs/dir.c | 2 - fs/smbfs/file.c | 1 - fs/squashfs/Kconfig | 1 - fs/udf/Kconfig | 1 - fs/udf/dir.c | 2 - fs/udf/file.c | 1 - fs/ufs/Kconfig | 2 +- include/linux/fs.h | 5 + kernel/power/Kconfig | 2 +- lib/Kconfig.debug | 2 +- lib/kernel_lock.c | 37 +- net/bluetooth/hidp/Kconfig | 1 - net/ipx/Kconfig | 1 - net/irda/Kconfig | 2 +- net/irda/irnet/Kconfig | 2 +- net/socket.c | 1 - net/sunrpc/Kconfig | 4 +- net/wanrouter/Kconfig | 2 +- net/x25/Kconfig | 2 +- sound/Kconfig | 2 +- sound/core/control.c | 2 - sound/core/oss/pcm_oss.c | 2 - sound/core/pcm_native.c | 2 - sound/core/seq/seq_clientmgr.c | 2 - sound/oss/au1550_ac97.c | 30 +- sound/oss/dmasound/dmasound_core.c | 2 - sound/oss/msnd_pinnacle.c | 2 - sound/oss/sh_dac_audio.c | 3 - sound/oss/swarm_cs4297a.c | 3 - sound/oss/vwsnd.c | 2 - sound/soc/soc-core.c | 2 - virt/kvm/kvm_main.c | 1 - 248 files changed, 190 insertions(+), 516 deletions(-) The rest: arch/arm/lib/uaccess_with_memcpy.c | 1 + arch/x86/configs/x86_64_defconfig | 29 +- arch/x86/kernel/microcode_core.c | 6 +- block/bsg.c | 2 - block/compat_ioctl.c | 8 +- block/ioctl.c | 24 +- drivers/block/DAC960.c | 4 +- drivers/block/aoe/aoechr.c | 6 +- drivers/block/cciss.c | 4 +- drivers/block/paride/pg.c | 4 +- drivers/block/paride/pt.c | 16 +- drivers/char/briq_panel.c | 1 + drivers/char/dsp56k.c | 1 + drivers/char/hpet.c | 96 +++-- drivers/char/mwave/mwavedd.c | 1 + drivers/char/nvram.c | 7 +- drivers/char/pcmcia/cm4000_cs.c | 1 + drivers/char/pcmcia/cm4040_cs.c | 1 + drivers/char/random.c | 2 + drivers/char/snsc.c | 1 + drivers/char/tlclk.c | 1 + drivers/char/toshiba.c | 1 + drivers/char/xilinx_hwicap/xilinx_hwicap.c | 1 + drivers/gpu/vga/vgaarb.c | 4 +- drivers/hid/hidraw.c | 1 + drivers/input/serio/serio_raw.c | 1 + drivers/isdn/capi/capifs.c | 10 +- drivers/md/dm-ioctl.c | 2 + drivers/media/dvb/dvb-core/dvbdev.c | 1 + drivers/misc/phantom.c | 1 + drivers/pci/proc.c | 4 +- drivers/pcmcia/pcmcia_ioctl.c | 23 +- drivers/sbus/char/display7seg.c | 1 + drivers/sbus/char/jsflash.c | 20 +- drivers/scsi/aacraid/linit.c | 1 + drivers/scsi/ch.c | 1 + drivers/scsi/sg.c | 22 +- drivers/usb/core/file.c | 1 + drivers/usb/core/inode.c | 5 + drivers/usb/gadget/inode.c | 12 +- drivers/usb/misc/usblcd.c | 1 + drivers/usb/mon/mon_bin.c | 14 +- drivers/watchdog/cpwd.c | 1 + fs/adfs/super.c | 8 +- fs/affs/super.c | 14 +- fs/afs/super.c | 5 + fs/autofs/root.c | 67 +++- fs/autofs4/root.c | 69 +++- fs/bad_inode.c | 4 + fs/bfs/inode.c | 7 +- fs/block_dev.c | 20 +- fs/cifs/cifsfs.c | 9 +- fs/coda/inode.c | 8 +- fs/compat_ioctl.c | 43 +-- fs/ecryptfs/main.c | 4 + fs/exec.c | 6 - fs/exofs/super.c | 1 - fs/ext2/inode.c | 5 +- fs/ext2/super.c | 58 ++- fs/ext3/super.c | 12 - fs/ext4/super.c | 11 - fs/fat/dir.c | 11 +- fs/fat/fat.h | 2 +- fs/fat/file.c | 33 ++- fs/fat/namei_msdos.c | 7 +- fs/fat/namei_vfat.c | 7 +- fs/freevxfs/vxfs_lookup.c | 1 + fs/freevxfs/vxfs_super.c | 7 +- fs/hfs/super.c | 6 +- fs/hfsplus/super.c | 5 - fs/hpfs/super.c | 8 +- fs/hppfs/hppfs.c | 2 +- fs/ioctl.c | 2 + fs/isofs/dir.c | 1 + fs/isofs/inode.c | 8 +- fs/jffs2/super.c | 11 +- fs/jfs/super.c | 22 +- fs/locks.c | 110 +++-- fs/namespace.c | 2 - fs/ncpfs/inode.c | 8 +- fs/nfs/super.c | 24 + fs/nilfs2/ioctl.c | 1 - fs/nilfs2/super.c | 10 - fs/ntfs/super.c | 24 +- fs/ocfs2/stack_user.c | 1 + fs/ocfs2/super.c | 5 + fs/proc/base.c | 10 +- fs/proc/inode.c | 8 +- fs/qnx4/dir.c | 1 + fs/qnx4/inode.c | 8 +- fs/read_write.c | 8 + fs/reiserfs/super.c | 4 + fs/smbfs/inode.c | 5 + fs/squashfs/super.c | 6 + fs/super.c | 3 - fs/udf/super.c | 8 +- fs/ufs/super.c | 5 + include/linux/auto_fs.h | 1 + include/linux/blkdev.h | 6 + include/linux/ext2_fs_sb.h | 6 + include/linux/fs.h | 2 + include/linux/sched.h | 2 + include/linux/smp_lock.h | 57 ++- init/main.c | 5 - kernel/cgroup.c | 4 - kernel/perf_event.c | 2 + kernel/ptrace.c | 10 - kernel/sched.c | 17 + kernel/trace/blktrace.c | 14 +- kernel/trace/trace.c | 8 - lib/Kconfig.debug | 17 + lib/Makefile | 4 + lib/kernel_lock.c | 104 +----- lib/kernel_lock_core.c | 307 +++++++++++++ net/sunrpc/cache.c | 30 +- net/sunrpc/rpc_pipe.c | 9 +- sound/core/timer.c | 5 +- sound/sound_core.c | 1 + virt/kvm/kvm_main.c | 6 + 120 files changed, 1156 insertions(+), 540 deletions(-)