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2012-07-24CIFS: Move is_path_accessible to ops structPavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Move informational tcon calls to ops structPavel Shilovsky
and rename variables in cifs_mount. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Move getting dfs referalls to ops structPavel Shilovsky
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Process reconnects for SMB2 sharesPavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add tree connect/disconnect capability for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add session setup/logoff capability for SMB2Pavel Shilovsky
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add capability to send SMB2 negotiate messagePavel Shilovsky
and add negotiate request type to let set_credits know that we are only on negotiate stage and no need to make a decision about disabling echos and oplocks. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Respect SMB2 header/max header sizePavel Shilovsky
Use SMB2 header size values for allocation and memset because they are bigger and suitable for both CIFS and SMB2. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Make demultiplex_thread work with SMB2 codePavel Shilovsky
Now we can process SMB2 messages: check message, get message id and wakeup awaiting routines. Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Fix a wrong pointer in atomic_openPavel Shilovsky
Commit 30d904947459cca2beb69e0110716f5248b31f2a caused a regression in cifs open codepath. Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking changes from David S Miller: 1) Remove the ipv4 routing cache. Now lookups go directly into the FIB trie and use prebuilt routes cached there. No more garbage collection, no more rDOS attacks on the routing cache. Instead we now get predictable and consistent performance, no matter what the pattern of traffic we service. This has been almost 2 years in the making. Special thanks to Julian Anastasov, Eric Dumazet, Steffen Klassert, and others who have helped along the way. I'm sure that with a change of this magnitude there will be some kind of fallout, but such things ought the be simple to fix at this point. Luckily I'm not European so I'll be around all of August to fix things :-) The major stages of this work here are each fronted by a forced merge commit whose commit message contains a top-level description of the motivations and implementation issues. 2) Pre-demux of established ipv4 TCP sockets, saves a route demux on input. 3) TCP SYN/ACK performance tweaks from Eric Dumazet. 4) Add namespace support for netfilter L4 conntrack helpers, from Gao Feng. 5) Add config mechanism for Energy Efficient Ethernet to ethtool, from Yuval Mintz. 6) Remove quadratic behavior from /proc/net/unix, from Eric Dumazet. 7) Support for connection tracker helpers in userspace, from Pablo Neira Ayuso. 8) Allow userspace driven TX load balancing functions in TEAM driver, from Jiri Pirko. 9) Kill off NLMSG_PUT and RTA_PUT macros, more gross stuff with embedded gotos. 10) TCP Small Queues, essentially minimize the amount of TCP data queued up in the packet scheduler layer. Whereas the existing BQL (Byte Queue Limits) limits the pkt_sched --> netdevice queuing levels, this controls the TCP --> pkt_sched queueing levels. From Eric Dumazet. 11) Reduce the number of get_page/put_page ops done on SKB fragments, from Alexander Duyck. 12) Implement protection against blind resets in TCP (RFC 5961), from Eric Dumazet. 13) Support the client side of TCP Fast Open, basically the ability to send data in the SYN exchange, from Yuchung Cheng. Basically, the sender queues up data with a sendmsg() call using MSG_FASTOPEN, then they do the connect() which emits the queued up fastopen data. 14) Avoid all the problems we get into in TCP when timers or PMTU events hit a locked socket. The TCP Small Queues changes added a tcp_release_cb() that allows us to queue work up to the release_sock() caller, and that's what we use here too. From Eric Dumazet. 15) Zero copy on TX support for TUN driver, from Michael S. Tsirkin. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1870 commits) genetlink: define lockdep_genl_is_held() when CONFIG_LOCKDEP r8169: revert "add byte queue limit support". ipv4: Change rt->rt_iif encoding. net: Make skb->skb_iif always track skb->dev ipv4: Prepare for change of rt->rt_iif encoding. ipv4: Remove all RTCF_DIRECTSRC handliing. ipv4: Really ignore ICMP address requests/replies. decnet: Don't set RTCF_DIRECTSRC. net/ipv4/ip_vti.c: Fix __rcu warnings detected by sparse. ipv4: Remove redundant assignment rds: set correct msg_namelen openvswitch: potential NULL deref in sample() tcp: dont drop MTU reduction indications bnx2x: Add new 57840 device IDs tcp: avoid oops in tcp_metrics and reset tcpm_stamp niu: Change niu_rbr_fill() to use unlikely() to check niu_rbr_add_page() return value niu: Fix to check for dma mapping errors. net: Fix references to out-of-scope variables in put_cmsg_compat() net: ethernet: davinci_emac: add pm_runtime support net: ethernet: davinci_emac: Remove unnecessary #include ...
2012-07-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 changes from Martin Schwidefsky: "No new functions, a few changes to make the code more robust, some cleanups and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits) s390/vtimer: rework virtual timer interface s390/dis: Add the servc instruction to the disassembler. s390/comments: unify copyright messages and remove file names s390/lgr: Add init check to lgr_info_log() s390/cpu init: use __get_cpu_var instead of per_cpu s390/idle: reduce size of s390_idle_data structure s390/idle: fix sequence handling vs cpu hotplug s390/ap: resend enable adapter interrupt request. s390/hypfs: Add missing get_next_ino() s390/dasd: add shutdown action s390/ipl: Fix ipib handling for "dumpreipl" shutdown action s390/smp: make absolute lowcore / cpu restart parameter accesses more robust s390/vmlogrdr: cleanup driver attribute usage s390/vmlogrdr: cleanup device attribute usage s390/ccwgroup: remove unused ccwgroup_device member s390/cio/chp: cleanup attribute usage s390/sigp: use sigp order code defines in assembly code s390/smp: use sigp cpu status definitions s390/smp/kvm: unifiy sigp definitions s390/smp: remove redundant check ...
2012-07-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lliubbo/blackfin Pull blackfin changes from Bob Liu: "The big changes are adding PM and HDMI support for bf60x, other patches are various bug fix and code cleanup." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lliubbo/blackfin: (48 commits) bf60x: fix build warning PM: add BF60x flash suspend and resume support blackfin: twi: read twi mmr via bfin_read macro dpm: deepsleep: reserve stack bf60x: cpufreq: fix anomaly 05000273 bf609: add adv7511 display support blackfin: cplb-nompu: fix ROM cplb size for bf609-ezkit bf60x: Add double fault, hardware error and NMI SEC handler bf60x: update anomaly id in serial and twi driver headers. bf60x: vs6624 pin update bf60x: add default anomaly setting. bf60x: update bf60x anomaly list. bf60x: sec: Enable sec interrupt source priority configuration. bf60x: sec: Clean up interrupt initialization code for SEC. bf609: reuse bf5xx-i2s-pcm.c as i2s pcm driver bf561: add capabilities in adv7183_inputs bf609: convert vs6624 blank_clocks to black_pixels blackfin: fix musb macro name cleanup: sec and linkport only built on bf60x bfin: pint: add pint suspend and resume ...
2012-07-24Merge tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreamingLinus Torvalds
Pull C6X changes from Mark Salter: - remove use of legacy irqs which really wasn't needed - add support for C66x SoC on EVMC6678 board - clean up compiler warning * tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: C6X: clean up compiler warning C6X: add basic support for TMS320C6678 SoC C6X: remove dependence on legacy IRQs C6X: remove megamod-pic requirement on direct-mapped core pic
2012-07-24CIFS: Add SMB2 credits supportPavel Shilovsky
For SMB2 protocol we can add more than one credit for one received request: it depends on CreditRequest field in SMB2 response header. Also we divide all requests by type: echoes, oplocks and others. Each type uses its own slot pull. Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Make transport routines work with SMB2Pavel Shilovsky
Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Map SMB2 status codes to POSIX errorsSteve French
Add mapping table for 32 bit SMB2 status codes to linux errors. Note that SMB2 does not use DOS/OS2 errors (ever) so mapping to DOS/OS2 errors as a common network subset (as we do for cifs) doesn't help. And note that the set of status codes is much more complete here. Signed-off-by: Steve French <sfrench@us.ibm.com> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Add SMB2 status codesPavel Shilovsky
Reviewed-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Rename 7 error codes to NT_ stylePavel Shilovsky
and consider such codes as CIFS errors. Reviewed-by: Jeff Layton <jlayton@samba.org> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Rename Get/FreeXid and make them work with unsigned intPavel Shilovsky
Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Move protocol specific tcon/tdis code to ops structPavel Shilovsky
and rename variables around the code changes. Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24CIFS: Move protocol specific session setup/logoff code to ops structPavel Shilovsky
Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24i2c-omap: Add support for I2C_M_STOP message flagLaurent Pinchart
Generate a stop condition after each message marked with I2C_M_STOP. [JD: Add I2C_FUNC_PROTOCOL_MANGLING.] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c: Fall back to emulated SMBus if the operation isn't supported nativelyLaurent Pinchart
Adapter drivers might support only a subset of the SMBus operations natively. Those drivers currently have to manually emulate unsupported operations using I2C. Make the i2c_smbus_xfer() function fall back to i2c_smbus_xfer_emulated() when the adapter's .smbus_xfer() operation returns -EOPNOTSUPP, like it already does when the .smbus_xfer() operation isn't available at all. [JD: Minor optimization.] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c: Add SCCB supportLaurent Pinchart
SCCB is a serial communication bus developed by Omnivision. Its 2-wire mode is very similar to SMBus byte data transactions, but requires the controller to ignore the ACK bit and to insert a stop condition after each message. Add a device SCCB flag and a message stop flag to be passed to controller drivers. [JD: Kill rogue definition in go7007 driver.] Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-tiny-usb: Add support for the Robofuzz OSIF USB/I2C converterEmmanuel Deloget
Robofuzz OSIF is a generic USB/iIC interface that embeds an ATMega8A AVR-RISC microcontroler. The device is based upon Till Harbaum's i2c-tiny-usb and although it enhances the original design with further functionnalities it still maintain compatibility with it with respect to the USB/I2C interface. Signed-off-by: Emmanuel Deloget <logout@free.fr> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Enable IRQ for byte_by_byte transactionsDaniel Kurtz
Byte-by-byte transactions are used primarily for accessing I2C devices with an SMBus controller. For these transactions, for each byte that is read or written, the SMBus controller generates a BYTE_DONE IRQ. The isr reads/writes the next byte, and clears the IRQ flag to start the next byte. On the penultimate IRQ, the isr also sets the LAST_BYTE flag. There is no locking around the cmd/len/count/data variables, since the I2C adapter lock ensures there is never multiple simultaneous transactions for the same device, and the driver thread never accesses these variables while interrupts might be occurring. The end result is faster I2C block read and write transactions. Note: This patch has only been tested and verified by doing I2C read and write block transfers on Cougar Point 6 Series PCH, as well as I2C read block transfers on ICH5. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Enable interrupts on ICH5/7/8/9/10Jean Delvare
Enable interrupts on more devices. ICH5, ICH7(-M) and ICH10 have been tested to work OK. ICH8 and ICH9 are expected to work just fine as they are very close to ICH7 and ICH10. Ultimately we want to enable this feature on at least every device since the ICH5, but for now we limit the exposure. We'll enable it for other devices if we don't get negative feedback. As a bonus, let the user know when interrupts are used. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24i2c-i801: Enable IRQ for SMBus transactionsDaniel Kurtz
Add a new 'feature' to i2c-i801 to enable using PCI interrupts. When the feature is enabled, then an isr is installed for the device's PCI IRQ. An I2C/SMBus transaction is always terminated by one of the following interrupt sources: FAILED, BUS_ERR, DEV_ERR, or on success: INTR. When the isr fires for one of these cases, it sets the ->status variable and wakes up the waitq. The waitq then saves off the status code, and clears ->status (in preparation for some future transaction). The SMBus controller generates an INTR irq at the end of each transaction where INTREN was set in the HST_CNT register. No locking is needed around accesses to priv->status since all writes to it are serialized: it is only ever set once in the isr at the end of a transaction, and cleared while no interrupts can occur. In addition, the I2C adapter lock guarantees that entire I2C transactions for a single adapter are always serialized. For this patch, the INTREN bit is set only for SMBus block, byte and word transactions, but not for I2C reads or writes. The use of the DS (BYTE_DONE) interrupt with byte-by-byte I2C transactions is implemented in a subsequent patch. The interrupt feature has only been enabled for COUGARPOINT hardware. In addition, it is disabled if SMBus is using the SMI# interrupt. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Consolidate pollingJean Delvare
(Based on earlier work by Daniel Kurtz.) Come up with a consistent, driver-wide strategy for event polling. For intermediate steps of byte-by-byte block transactions, check for BYTE_DONE or any error flag being set. At the end of every transaction (regardless of PEC being used), check for both BUSY being cleared and INTR or any error flag being set. This ensures proper action for all transaction types. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Daniel Kurtz <djkurtz@chromium.org>
2012-07-24i2c-i801: Drop ENABLE_INT9Daniel Kurtz
Later patches enable interrupts. This preliminary patch removes the older unsupported ENABLE_INT9 flag. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Rename some SMBHSTCNT bit constantsDaniel Kurtz
Rename the SMBHSTCNT register bit access constants to match the style of other register bits. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Check and return errors during byte-by-byte transfersDaniel Kurtz
If an error is detected in the polling loop, abort the transaction and return an error code. * DEV_ERR is set if the device does not respond with an acknowledge, and the SMBus controller times out (minimum 25ms). * BUS_ERR is set if a bus arbitration collision is detected. In other words, when the SMBus controller tries to generate a START condition, but detects that the SMBDATA is being held low, usually by another SMBus/I2C master. * FAILED is only set if a transaction is stopped by software (using the SMBHSTCNT KILL bit). Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Clear only status bits in HST_STSDaniel Kurtz
Writing back the whole status register could clear unwanted bits. In particular, it could clear the "INUSE_STS" bit, which is a 'hardware semaphore', that might be useful to use some day. To prepare for this, let's ban writing back the whole status to register HST_STS, of which this is the only instance. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-i801: Refactor use of LAST_BYTE in i801_block_transaction_byte_by_byteDaniel Kurtz
As a slight optimization, pull some logic out of the polling loop during byte-by-byte transactions by just setting the I801_LAST_BYTE bit, as defined in the i801 (PCH) datasheet, when reading the last byte of a byte-by-byte I2C_SMBUS_READ. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-smbus: Use module_i2c_driver()Fabio Estevam
Using module_i2c_driver() makes the code smaller and cleaner. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c/writing-clients: Mention module_i2c_driver()Jean Delvare
Based on a previous patch from Peter Meerwald. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Peter Meerwald <p.meerwald@bct-electronic.com>
2012-07-24i2c-piix4: Support AMD auxiliary SMBus controllerAndrew Armenia
Some AMD chipsets, such as the SP5100, have an auxiliary SMBus controller with a second set of registers. This patch adds support for this auxiliary controller. Tested on ASUS KCMA-D8 motherboard. Signed-off-by: Andrew Armenia <andrew@asquaredlabs.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-piix4: Separate registration and probing codeAndrew Armenia
Some chipsets have multiple sets of SMBus registers each controlling a separate SMBus. Supporting these chipsets properly will require registering multiple I2C adapters for one piix4. The code to initialize and register the i2c_adapter structure has been separated from piix4_probe and allows registration of a piix4 adapter given its base address. Note that the i2c_adapter and i2c_piix4_adapdata structures are now dynamically allocated. Signed-off-by: Andrew Armenia <andrew@asquaredlabs.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c-piix4: Eliminate piix4_smba global variableAndrew Armenia
Some chipsets have multiple sets of piix4-compatible SMBus registers. Eliminating the global variable will allow these chipsets to be fully supported. Return value from piix4_setup and piix4_sb800_setup now returns the smba value detected. This is stored in a struct i2c_piix4_adapdata. Thus the global variable is eliminated. Signed-off-by: Andrew Armenia <andrew@asquaredlabs.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24i2c/busses: Use module_pci_driverAxel Lin
Convert the drivers in drivers/i2c/busses/* to usemodule_pci_driver() macro which makes the code smaller and a bit simpler. Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Olof Johansson <olof@lixom.net> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Tomoya MORINAGA <tomoya.rohm@gmail.com>
2012-07-24i2c: Update Guenter Roeck's e-mail addressGuenter Roeck
My old e-mail address won't be valid for much longer. Time to update it. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24sched: Fix race in task_group()Peter Zijlstra
Stefan reported a crash on a kernel before a3e5d1091c1 ("sched: Don't call task_group() too many times in set_task_rq()"), he found the reason to be that the multiple task_group() invocations in set_task_rq() returned different values. Looking at all that I found a lack of serialization and plain wrong comments. The below tries to fix it using an extra pointer which is updated under the appropriate scheduler locks. Its not pretty, but I can't really see another way given how all the cgroup stuff works. Reported-and-tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1340364965.18025.71.camel@twins Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24sched: Improve balance_cpu() to consider other cpus in its group as target ↵Srivatsa Vaddagiri
of (pinned) task Current load balance scheme requires only one cpu in a sched_group (balance_cpu) to look at other peer sched_groups for imbalance and pull tasks towards itself from a busy cpu. Tasks thus pulled by balance_cpu could later get picked up by cpus that are in the same sched_group as that of balance_cpu. This scheme however fails to pull tasks that are not allowed to run on balance_cpu (but are allowed to run on other cpus in its sched_group). That can affect fairness and in some worst case scenarios cause starvation. Consider a two core (2 threads/core) system running tasks as below: Core0 Core1 / \ / \ C0 C1 C2 C3 | | | | v v v v F0 T1 F1 [idle] T2 F0 = SCHED_FIFO task (pinned to C0) F1 = SCHED_FIFO task (pinned to C2) T1 = SCHED_OTHER task (pinned to C1) T2 = SCHED_OTHER task (pinned to C1 and C2) F1 could become a cpu hog, which will starve T2 unless C1 pulls it. Between C0 and C1 however, C0 is required to look for imbalance between cores, which will fail to pull T2 towards Core0. T2 will starve eternally in this case. The same scenario can arise in presence of non-rt tasks as well (say we replace F1 with high irq load). We tackle this problem by having balance_cpu move pinned tasks to one of its sibling cpus (where they can run). We first check if load balance goal can be met by ignoring pinned tasks, failing which we retry move_tasks() with a new env->dst_cpu. This patch modifies load balance semantics on who can move load towards a given cpu in a given sched_domain. Before this patch, a given_cpu or a ilb_cpu acting on behalf of an idle given_cpu is responsible for moving load to given_cpu. With this patch applied, balance_cpu can in addition decide on moving some load to a given_cpu. There is a remote possibility that excess load could get moved as a result of this (balance_cpu and given_cpu/ilb_cpu deciding *independently* and at *same* time to move some load to a given_cpu). However we should see less of such conflicting decisions in practice and moreover subsequent load balance cycles should correct the excess load moved to given_cpu. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4FE06CDB.2060605@linux.vnet.ibm.com [ minor edits ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24sched: Reset loop counters if all tasks are pinned and we need to redo load ↵Prashanth Nageshappa
balance While load balancing, if all tasks on the source runqueue are pinned, we retry after excluding the corresponding source cpu. However, loop counters env.loop and env.loop_break are not reset before retrying, which can lead to failure in moving the tasks. In this patch we reset env.loop and env.loop_break to their inital values before we retry. Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4FE06EEF.2090709@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24sched: Reorder 'struct lb_env' members to reduce its sizePrashanth Nageshappa
Members of 'struct lb_env' are not in appropriate order to reuse compiler added padding on 64bit architectures. In this patch we reorder those struct members and help reduce the size of the structure from 96 bytes to 80 bytes on 64 bit architectures. Suggested-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4FE06DDE.7000403@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24sched: Improve scalability via 'CPU buddies', which withstand random ↵Mike Galbraith
perturbations Traversing an entire package is not only expensive, it also leads to tasks bouncing all over a partially idle and possible quite large package. Fix that up by assigning a 'buddy' CPU to try to motivate. Each buddy may try to motivate that one other CPU, if it's busy, tough, it may then try its SMT sibling, but that's all this optimization is allowed to cost. Sibling cache buddies are cross-wired to prevent bouncing. 4 socket 40 core + SMT Westmere box, single 30 sec tbench runs, higher is better: clients 1 2 4 8 16 32 64 128 .......................................................................... pre 30 41 118 645 3769 6214 12233 14312 post 299 603 1211 2418 4697 6847 11606 14557 A nice increase in performance. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1339471112.7352.32.camel@marge.simpson.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24cpusets: Remove/update outdated commentsSrivatsa S. Bhat
cpuset_track_online_cpus() is no longer present. So remove the outdated comment and replace it with reference to cpuset_update_active_cpus() which is its equivalent. Also, we don't lack memory hot-unplug anymore. And David Rientjes pointed out how it is dealt with. So update that comment as well. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120524141700.3692.98192.stgit@srivatsabhat.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24cpusets, hotplug: Restructure functions that are invoked during hotplugSrivatsa S. Bhat
Separate out the cpuset related handling for CPU/Memory online/offline. This also helps us exploit the most obvious and basic level of optimization that any notification mechanism (CPU/Mem online/offline) has to offer us: "We *know* why we have been invoked. So stop pretending that we are lost, and do only the necessary amount of processing!". And while at it, rename scan_for_empty_cpusets() to scan_cpusets_upon_hotplug(), which is more appropriate considering how it is restructured. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120524141650.3692.48637.stgit@srivatsabhat.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-24cpusets, hotplug: Implement cpuset tree traversal in a helper functionSrivatsa S. Bhat
At present, the functions that deal with cpusets during CPU/Mem hotplug are quite messy, since a lot of the functionality is mixed up without clear separation. And this takes a toll on optimization as well. For example, the function cpuset_update_active_cpus() is called on both CPU offline and CPU online events; and it invokes scan_for_empty_cpusets(), which makes sense only for CPU offline events. And hence, the current code ends up unnecessarily traversing the cpuset tree during CPU online also. As a first step towards cleaning up those functions, encapsulate the cpuset tree traversal in a helper function, so as to facilitate upcoming changes. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120524141635.3692.893.stgit@srivatsabhat.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>