summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2010-08-10perf ui: Move ui_helpline routines to separate file in util/ui/Arnaldo Carvalho de Melo
LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-10perf ui: Shorten ui_browser member namesArnaldo Carvalho de Melo
LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-10block: make sure that REQ_* types are seen even with CONFIG_BLOCK=nJens Axboe
These form the basis of the basic WRITE etc primitives, so we need them to be always visible. Otherwise we see errors like: mm/filemap.c:2164: error: 'REQ_WRITE' undeclared fs/read_write.c:362: error: 'REQ_WRITE' undeclared fs/splice.c:1108: error: 'REQ_WRITE' undeclared fs/aio.c:1496: error: 'REQ_WRITE' undeclared Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-10Merge branch 'next' into for-linusDmitry Torokhov
2010-08-10Input: xpad - add USB-ID for PL-3601 Xbox 360 padChristoph Fritz
This patch adds USB Vendor and Product ID for Pelican PL-3601 'TSZ' Wired Xbox 360 Controller to the device table. Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-10Input: cy8ctmg100_ts - signedness bugDan Carpenter
"ret" should be signed here or the error handling doesn't work. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-10ASoC: add AD1980 obsolete informationSonic Zhang
This codec has been obsoleted by ADI, so add appropriate warnings to the source tree to dissuade people from using in new designs based on driver support. Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-08-10ASoC: register cache should be 1 byte aligned for 1 byte long registerCliff Cai
Signed-off-by: Cliff Cai <cliff.cai@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: stable@kernel.org
2010-08-10NFS: allow close-to-open cache semantics to apply to root of NFS filesystemNeil Brown
To obey NFS cache semantics, the client must verify the cached attributes when a file is opened. In most cases this is done by a call to d_validate as one of the last steps in path_walk. However for the root of a filesystem, d_validate is only ever called on the mounted-on filesystem (except when the path ends '.' or '..'). So NFS has no chance to validate the attributes. So, in nfs_opendir, we revalidate the attributes if the opened directory is the mountpoint. This may cause double-validation for "." and ".." lookups, but that is better than missing regular /path/name lookups completely. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-08-10SUNRPC: fix NFS client over TCP hangs due to packet loss (Bug 16494)Andy Chittenden
When reusing a TCP connection, ensure that it's aborted if a previous shutdown attempt has been made on that connection so that the RPC over TCP recovery mechanism succeeds. Signed-off-by: Andy Chittenden <andyc.bluearc@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-08-10Bluetooth: Use 3-DH5 payload size for default ERTM max PDU sizeMat Martineau
The previous value of 672 for L2CAP_DEFAULT_MAX_PDU_SIZE is based on the default L2CAP MTU. That default MTU is calculated from the size of two DH5 packets, minus ACL and L2CAP b-frame header overhead. ERTM is used with newer basebands that typically support larger 3-DH5 packets, and i-frames and s-frames have more header overhead. With clean RF conditions, basebands will typically attempt to use 1021-byte 3-DH5 packets for maximum throughput. Adjusting for 2 bytes of ACL headers plus 10 bytes of worst-case L2CAP headers yields 1009 bytes of payload. This PDU size imposes less overhead for header bytes and gives the baseband the option to choose 3-DH5 packets, but is small enough for ERTM traffic to interleave well with other L2CAP or SCO data. 672-byte payloads do not allow the most efficient over-the-air packet choice, and cannot achieve maximum throughput over BR/EDR. Signed-off-by: Mat Martineau <mathewm@codeaurora.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2010-08-10Bluetooth: Fix incorrect setting of remote_tx_win for L2CAP ERTMMat Martineau
remote_tx_win is intended to be set on receipt of an L2CAP configuration request. The value is used to determine the size of the transmit window on the remote side of an ERTM connection, so L2CAP can stop sending frames when that remote window is full. An incorrect remote_tx_win value will cause the stack to not fully utilize the tx window (performance impact), or to overfill the remote tx window (causing dropped frames or a disconnect). This patch removes an extra setting of remote_tx_win when a configuration response is received. The transmit window has a different meaning in a response - it is an informational value less than or equal to the local tx_win. Signed-off-by: Mat Martineau <mathewm@codeaurora.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2010-08-10Bluetooth: Change default L2CAP ERTM retransmit timeoutMat Martineau
The L2CAP specification requires that the ERTM retransmit timeout be at least 2 seconds for BR/EDR connections. Signed-off-by: Mat Martineau <mathewm@codeaurora.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2010-08-10Bluetooth: Fix endianness issue with L2CAP MPS configurationMat Martineau
Incoming configuration values must be converted to native CPU order before use. This fixes a bug where a little-endian MPS value is compared to a native CPU value. On big-endian processors, this can cause ERTM and streaming mode segmentation to produce PDUs that are larger than the remote stack is expecting, or that would produce fragmented skbs that the current FCS code cannot handle. Signed-off-by: Mat Martineau <mathewm@codeaurora.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2010-08-10Fix CONFIG_CROSS_COMPILE issue in .configYegor Yefremov
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-08-10intel_mid_battery: Fix battery scalingAlan Cox
There are 3600 seconds per not 3600 hours per second. Correcting this along with the previous fix gives sensible numbers. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
2010-08-10intel_mid_battery: Fix the argument order to intel_scu_ipc_commandArjan van de Ven
The arguments to intel_scu_ipc_command are "command, subcommand" the battery driver got this the wrong way around. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
2010-08-10net: Use NET_XMIT_SUCCESS where possible.Ben Greear
This is based on work originally done by Patric McHardy. Signed-off-by: Ben Greear <greearb@candelatech.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10isdn: mISDN: call pci_disable_device() if pci_probe() failedKulikov Vasiliy
Driver should call pci_disable_device() if it returns from pci_probe() with error. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10isdn: avm: call pci_disable_device() if pci_probe() failedKulikov Vasiliy
Driver should call pci_disable_device() if it returns from pci_probe() with error. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10isdn: avm: call pci_disable_device() if pci_probe() failedKulikov Vasiliy
Driver should call pci_disable_device() if it returns from pci_probe() with error. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10usbnet: rx_submit() should return an error code.David S. Miller
This patch makes rx_submit() return an error code, and makes some call sites that care check the return value. This is important because it lets us properly handle cases where the device isn't ready to handle URB submissions (e.g., when it is autosuspended under some drivers); previously, we would attempt and fail to submit URBs and reschedule ourselves to try and fail again. This patch is against Linus's 2.6 repo commit 45d7f32c7a43cbb9592886d38190e379e2eb2226. Signed-Off-By: Elizabeth Jones <ellyjones@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10ALSA: hda - Adding support for new IDT 92HD87XX codecsCharles Chin
Added the entries for 92HD87B1/3 and 92HD87B2/4 codecs. These are compatible with existing 83xxx codecs. Signed-off-by: Charles Chin <Charles.Chin@idt.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-08-10ASoC: Fix inverted mute controls for WM8580Mark Brown
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Cc: stable@kernel.org
2010-08-10pkt_sched: Add some basic qdisc class ops verification. Was: [PATCH] sfq: ↵Jarek Poplawski
add dummy bind/unbind handles Verify in register_qdisc() some basic qdisc class handlers are present. Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10pkt_sched: sch_sfq: Add dummy unbind_tcf and put handles. Was: [PATCH] sfq: ↵Jarek Poplawski
add dummy bind/unbind handles Add dummy .unbind_tcf and .put qdisc class ops for easier verification. (All other schedulers have it like this.) Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10qlcnic: using too much stackDan Carpenter
qlcnic_pci_info structs are 128 bytes so an array of 8 uses 1024 bytes. That's a lot if you run with 4K stacks. I allocated them with kcalloc() instead. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10qlcnic: clean up qlcnic_init_pci_info()Dan Carpenter
In the original code we allocated memory conditionally and freed it in the error handling unconditionally. It turns out that this function is only called during initialization and "adapter->npars" and "adapter->eswitch" are always NULL at the start of the function. I removed those checks. Also since I was cleaning things, I changed the error handling for qlcnic_get_pci_info() and pulled everything in an indent level. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10ALSA: HDA: Use model=auto for LG R510David Henningsson
Two users report model=auto is needed to make the internal mic work properly. BugLink: https://bugs.launchpad.net/bugs/495134 Signed-off-by: David Henningsson <david.henningsson@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-08-10ALSA: hda - Update model entries in HD-Audio-Models.txtTakashi Iwai
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-08-10phy.c: fix kernel-doc warningsRandy Dunlap
Fix phy.c kernel-doc notation: Warning(drivers/net/phy/phy.c:313): No description found for parameter 'ifr' Warning(drivers/net/phy/phy.c:313): Excess function parameter 'mii_data' description in 'phy_mii_ioctl' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10net/sock.h: add missing kernel-doc notationRandy Dunlap
Add missing kernel-doc notation to struct sock: Warning(include/net/sock.h:324): No description found for parameter 'sk_peer_pid' Warning(include/net/sock.h:324): No description found for parameter 'sk_peer_cred' Warning(include/net/sock.h:324): No description found for parameter 'sk_classid' Warning(include/net/sock.h:324): Excess struct/union/enum/typedef member 'sk_peercred' description in 'sock' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10etherdevice.h: fix kernel-doc typoRandy Dunlap
Fix etherdevice.h parameter name typo in kernel-doc: Warning(include/linux/etherdevice.h:138): No description found for parameter 'hwaddr' Warning(include/linux/etherdevice.h:138): Excess function parameter 'addr' description in 'dev_hw_addr_random' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10farsync: Fix compile warnings.David S. Miller
drivers/net/wan/farsync.c: In function 'fst_intr_rx': drivers/net/wan/farsync.c:1312: warning: cast to pointer from integer of different size drivers/net/wan/farsync.c: In function 'do_bottom_half_tx': drivers/net/wan/farsync.c:1407: warning: cast to pointer from integer of different size The "skb" and "mem" arguments being passed here are DMA addresses being programmed into the hardware registers, so pass them as the type that they actually are. And use the correct printf formatting in debug logging statements for these things to match the type change. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-10ALSA: hda: document VIA modelsClemens Ladisch
Add documentation about the autodetection of the VIA codec models to avoid the false impression that they are not supported. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-08-10ALSA: hda - patch_nvhdmi.c: Add missing codec IDs, unify namesStephen Warren
* Add missing codec IDs. * Modify some existing codec names for discrete GPUs to match newly added IDs. Note: existing names were a mixture of marketing and engineering GPU names. Equally, there's no reason that codec IDs have to be specific to a particular GPU or board, so identify codecs in a less marketing-oriented fashion. * Reformat codec ID table so it's easier to read, for me at least. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (59 commits) igbvf.txt: Add igbvf Documentation igb.txt: Add igb documentation e100/e1000*/igb*/ixgb*: Add missing read memory barrier ixgbe: fix build error with FCOE_CONFIG without DCB_CONFIG netxen: protect tx timeout recovery by rtnl lock isdn: gigaset: use after free isdn: gigaset: add missing unlock solos-pci: Fix race condition in tasklet RX handling pkt_sched: Fix sch_sfq vs tcf_bind_filter oops net: disable preemption before call smp_processor_id() tcp: no md5sig option size check bug iwlwifi: fix locking assertions iwlwifi: fix TX tracer isdn: fix information leak net: Fix napi_gro_frags vs netpoll path usbnet: remove noisy and hardly useful printk rtl8180: avoid potential NULL deref in rtl8180_beacon_work ath9k: Remove myself from the MAINTAINERS list libertas: scan before assocation if no BSSID was given libertas: fix association with some APs by using extended rates ...
2010-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6: tx493xide: use min_t() macro instead of min() drivers/ide: Use memdup_user via82cxxx: fix typo for VT6415 PCIE PATA IDE Host Controller support. ide-cd: Do not access completed requests in the irq handler
2010-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Update defconfig. sparc: Kill user copy check code. sparc64: Fix perf_arch_get_caller_regs(). sparc64: Add missing ID to parport probing code.
2010-08-09Merge branch 'rs485fix' of git://www.jni.nu/crisLinus Torvalds
* 'rs485fix' of git://www.jni.nu/cris: CRIS: ioctl for getting RS485 information
2010-08-09Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: fix build with make 3.82 Revert "Input: appletouch - fix integer overflow issue" memblock: Fix memblock_is_region_reserved() to return a boolean powerpc: Trim defconfigs powerpc: fix i8042 module build error sound/soc: mpc5200_psc_ac97: Use gpio pins for cold reset powerpc/5200: add mpc5200_psc_ac97_gpio_reset
2010-08-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (32 commits) Blackfin: gpio: add a debounce stub Blackfin: update defconfigs Blackfin: remove CONFIG_MEM_GENERIC_BOARD Blackfin: dpmc: punt unnecessary RTC_ISTAT clearing Blackfin: unify rotary encoder bitmasks Blackfin: unify SDH/RSI bitmasks Blackfin: BF54x: tweak DMAC MMR naming to match other ports Blackfin: TWI: clean up the MMR names Blackfin: add EVT_OVERRIDE/IPRIO core MMR helpers Blackfin: add support for dynamic ftrace Blackfin: add support for LZO compressed kernels Blackfin: portmux: fix peripheral map overflow when requesting pins Blackfin: document SPI CS limitations with CPHA=0 Blackfin: remove useless and outdated documentation Blackfin: BF51x/BF52x: support GPIO Hysteresis/Schmitt Trigger options Blackfin: gpio/portmux: clean up whitespace corruption Blackfin: make sure mmiowb inserts a write barrier with SSYNC Blackfin: fix DMA/cache bug when resuming from suspend to RAM Blackfin: BF51x: fix handling of PH8 (the "internal" SPI0SEL4 pin) Blackfin: add a GPIO_DEFAULT_BOOT_SPI_CS ...
2010-08-09Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (30 commits) DMAENGINE: at_hdmac: locking fixlet DMAENGINE: pch_dma: kill another usage of __raw_{read|write}l dma: dmatest: fix potential sign bug ioat2: catch and recover from broken vtd configurations v6 DMAENGINE: add runtime slave control to COH 901 318 v3 DMAENGINE: add runtime slave config to DMA40 v3 DMAENGINE: generic slave channel control v3 dmaengine: Driver for Topcliff PCH DMA controller intel_mid: Add Mrst & Mfld DMA Drivers drivers/dma: Eliminate a NULL pointer dereference dma/timb_dma: compile warning on 32 bit DMAENGINE: ste_dma40: support older silicon DMAENGINE: ste_dma40: support disabling physical channels DMAENGINE: ste_dma40: no disabled phy channels on ux500 DMAENGINE: ste_dma40: fix suspend bug DMAENGINE: ste_dma40: add DB8500 memcpy channels DMAENGINE: ste_dma40: no flow control on memcpy DMAENGINE: ste_dma40: arch updates for LCLA and LCPA DMAENGINE: ste_dma40: allocate LCLA dynamically DMAENGINE: ste_dma40: no premature stop ... Fix up trivial conflicts in arch/arm/mach-ux500/devices-db8500.c
2010-08-09drivers/char/vt.c:vc_do_resize(): local var `end' should be unsigned longqiaochong
According include/linux/console_struct.h,vc_scr_end is unsigned long. struct vc_data { unsigned short vc_num; /* Console number */ unsigned int vc_cols; /* [#] Console size */ unsigned int vc_rows; unsigned int vc_size_row; /* Bytes per row */ unsigned int vc_scan_lines; /* # of scan lines */ unsigned long vc_origin; /* [!] Start of real screen */ unsigned long vc_scr_end; /* [!] End of real screen */ unsigned long vc_visible_origin; /* [!] Top of visible window */ unsigned int vc_top, vc_bottom; /* Scrolling region */ const struct consw *vc_sw; unsigned short *vc_screenbuf; ... } Signed-off-by: qiaochong <qiaochong@loongson.cn> Cc: Greg KH <greg@kroah.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09drivers/char/vt.c: fix vc->vc_origin on take_over_console()qiaochong
kernel will die on some platform when switch from vga mode to framebuffer mode. The reason of this bug is that bind_con_driver reset vc->vc_origin to (unsigned long)vc->vc_screenbuf. On vgacon vc->vc_origin is not releated to vc->vc_screenbuf,if set vc->vc_origin to vc->vc_screenbuf,kernel will die on vc_do_resize. static int vc_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, struct vc_data *vc, unsigned int cols, unsigned int lines) { unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0; unsigned int old_cols, old_rows, old_row_size, old_screen_size; unsigned int new_cols, new_rows, new_row_size, new_screen_size; unsigned int end, user; ... end = (old_rows > new_rows) ? old_origin + (old_row_size * new_rows) : vc->vc_scr_end; ... /* here for a test from vgacon to framebuffer: old_origin=0x810814a0,end=0xb00b8fa0,vc->vc_origin=0x810814a0 the code bellow will copy memory from 0x810814a0 to 0xb00b8fa0, this will cover kernel code,kernel died here. */ while (old_origin < end) { scr_memcpyw((unsigned short *) new_origin, (unsigned short *) old_origin, rlth); if (rrem) scr_memsetw((void *)(new_origin + rlth), vc->vc_video_erase_char, rrem); old_origin += old_row_size; new_origin += new_row_size; } ... } [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: qiaochong <qiaochong@loongson.cn> Cc: Greg KH <greg@kroah.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rwsem: smaller wrappers around rwsem_down_failed_commonMichel Lespinasse
More code can be pushed from rwsem_down_read_failed and rwsem_down_write_failed into rwsem_down_failed_common. Following change adding down_read_critical infrastructure support also enjoys having flags available in a register rather than having to fish it out in the struct rwsem_waiter... Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rwsem: wake queued readers when writer blocks on active read lockMichel Lespinasse
This change addresses the following situation: - Thread A acquires the rwsem for read - Thread B tries to acquire the rwsem for write, notices there is already an active owner for the rwsem. - Thread C tries to acquire the rwsem for read, notices that thread B already tried to acquire it. - Thread C grabs the spinlock and queues itself on the wait queue. - Thread B grabs the spinlock and queues itself behind C. At this point A is the only remaining active owner on the rwsem. In this situation thread B could notice that it was the last active writer on the rwsem, and decide to wake C to let it proceed in parallel with A since they both only want the rwsem for read. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rwsem: let RWSEM_WAITING_BIAS represent any number of waiting threadsMichel Lespinasse
Previously each waiting thread added a bias of RWSEM_WAITING_BIAS. With this change, the bias is added only once to indicate that the wait list is non-empty. This has a few nice properties which will be used in following changes: - when the spinlock is held and the waiter list is known to be non-empty, count < RWSEM_WAITING_BIAS <=> there is an active writer on that sem - count == RWSEM_WAITING_BIAS <=> there are waiting threads and no active readers/writers on that sem Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rwsem: lighter active count checks when waking up readersMichel Lespinasse
In __rwsem_do_wake(), we can skip the active count check unless we come there from up_xxxx(). Also when checking the active count, it is not actually necessary to increment it; this allows us to get rid of the read side undo code and simplify the calculation of the final rwsem count adjustment once we've counted the reader threads to wake. The basic observation is the following. When there are waiter threads on a rwsem and the spinlock is held, other threads can only increment the active count by trying to grab the rwsem in down_xxxx(). However down_xxxx() will notice there are waiter threads and take the down_failed path, blocking to acquire the spinlock on the way there. Therefore, a thread observing an active count of zero with waiters queued and the spinlock held, is protected against other threads acquiring the rwsem until it wakes the last waiter or releases the spinlock. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09rwsem: fully separate code paths to wake writers vs readersMichel Lespinasse
This is in preparation for later changes in the series. In __rwsem_do_wake(), the first queued waiter is checked first in order to determine whether it's a writer or a reader. The code paths diverge at this point. The code that checks and increments the rwsem active count is duplicated on both sides - the point is that later changes in the series will be able to independently modify both sides. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Mike Waychison <mikew@google.com> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Ying Han <yinghan@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit (git 2.34.1) at 2025-09-19 09:53:46 +0000