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* rps: tcp: fix rps_sock_flow_table table updatesEric Dumazet2010-06-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | I believe a moderate SYN flood attack can corrupt RFS flow table (rps_sock_flow_table), making RPS/RFS much less effective. Even in a normal situation, server handling short lived sessions suffer from bad steering for the first data packet of a session, if another SYN packet is received for another session. We do following action in tcp_v4_rcv() : sock_rps_save_rxhash(sk, skb->rxhash); We should _not_ do this if sk is a LISTEN socket, as about each packet received on a LISTEN socket has a different rxhash than previous one. -> RPS_NO_CPU markers are spread all over rps_sock_flow_table. Also, it makes sense to protect sk->rxhash field changes with socket lock (We currently can change it even if user thread owns the lock and might use rxhash) This patch moves sock_rps_save_rxhash() to a sock locked section, and only for non LISTEN sockets. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ppp_generic: fix multilink fragment sizesBen McKeegan2010-06-04
| | | | | | | | | Fix bug in multilink fragment size calculation introduced by commit 9c705260feea6ae329bc6b6d5f6d2ef0227eda0a "ppp: ppp_mp_explode() redesign" Signed-off-by: Ben McKeegan <ben@netservers.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* syncookies: remove Kconfig text line about disabled-by-defaultFlorian Westphal2010-06-04
| | | | | | | | | syncookies default to on since e994b7c901ded7200b525a707c6da71f2cf6d4bb (tcp: Don't make syn cookies initial setting depend on CONFIG_SYSCTL). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* ixgbe: only check pfc bits in hang logic if pfc is enabledJohn Fastabend2010-06-04
| | | | | | | | | | | Only check pfc bits in hang logic if PFC is enabled. Previously, if DCB was enabled but PFC was disabled the incorrect pause bits would be checked. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Don Skidmore <donald.c.skidmore@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: check for refcount if pop a stacked dst_entrySteffen Klassert2010-06-04
| | | | | | | | | | | | | xfrm triggers a warning if dst_pop() drops a refcount on a noref dst. This patch changes dst_pop() to skb_dst_pop(). skb_dst_pop() drops the refcnt only on a refcounted dst. Also we don't clone the child dst_entry, so it is not refcounted and we can use skb_dst_set_noref() in xfrm_output_one(). Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2010-06-03
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6
| * mac80211: fix dialog token allocatorJohannes Berg2010-06-01
| | | | | | | | | | | | | | | | | | The dialog token allocator has apparently been broken since b83f4e15 ("mac80211: fix deadlock in sta->lock") because it got moved out under the spinlock. Fix it. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
| * mac80211: fix blockack-req processingJohannes Berg2010-06-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel reported that the paged RX changes had broken blockack request frame processing due to using data that wasn't really part of the skb data. Fix this using skb_copy_bits() for the needed data. As a side effect, this adds a check on processing too short frames, which previously this code could do. Reported-by: Daniel Halperin <dhalperi@cs.washington.edu> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Daniel Halperin <dhalperi@cs.washington.edu> Signed-off-by: John W. Linville <linville@tuxdriver.com>
| * ath5k: wake queues on resetBruno Randolf2010-06-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We can wake all queues after a chip reset since everything should be set up and we are ready to transmit. If we don't do that we might end up starting up with stopped queues, not beeing able to transmit. (This started to happen after "ath5k: clean up queue manipulation" but since periodic calibration also stopped and started the queues this effect was hidden most of the time). This way we can also get rid of the superfluous ath5k_reset_wake() function. Signed-off-by: Bruno Randolf <br1@einfach.org> Acked-by: Nick Kossifidis <mickflemm@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
* | ixgbe: return IXGBE_ERR_RAR_INDEX when out of rangeJeff Kirsher2010-06-03
| | | | | | | | | | | | | | | | | | | | | | Based on original patch from Shirley Ma <xma@us.ibm.com> Return IXGBE_ERR_RAR_INDEX when RAR index is out of range, instead of returning IXGBE_SUCCESS. CC: Shirley Ma <xma@us.ibm.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Don Skidmore <donald.c.skidmore@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | act_pedit: access skb->data safelyChangli Gao2010-06-03
| | | | | | | | | | | | | | | | | | | | | | | | | | access skb->data safely we should use skb_header_pointer() and skb_store_bits() to access skb->data to handle small or non-linear skbs. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- net/sched/act_pedit.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
* | sfc: Store port number in net_device::dev_idBen Hutchings2010-06-03
| | | | | | | | | | | | | | This exposes the port number to userland through sysfs. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | epic100: Test __BIG_ENDIAN instead of (non-existent) CONFIG_BIG_ENDIANRoland Dreier2010-06-03
| | | | | | | | | | | | | | | | | | | | | | | | Probably no one has used this driver on big-endian systems, since it was setting up descriptor swapping if CONFIG_BIG_ENDIAN is set, which it never is, since that symbol is not mentioned anywhere else in the kernel source. Switch this test to a check for __BIG_ENDIAN so it has a chance at working. Signed-off-by: Roland Dreier <rolandd@cisco.com> Acked-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tehuti: return -EFAULT on copy_to_user errorsDan Carpenter2010-06-03
| | | | | | | | | | | | | | | | copy_to_user() returns the number of bytes remaining but we want to return a negative error code here. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | isdn/kcapi: return -EFAULT on copy_from_user errorsDan Carpenter2010-06-03
| | | | | | | | | | | | | | | | | | | | copy_from_user() returns the number of bytes remaining but we should return -EFAULT here. The error code gets returned to the user. Both old_capi_manufacturer() and capi20_manufacturer() had other places that already returned -EFAULT so this won't break anything. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | e1000e: change logical negate to bitwiseDan Carpenter2010-06-03
| | | | | | | | | | | | | | | | | | | | The bitwise negate is intended here. With the logical negate the condition is always false. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Bruce Allan <bruce.w.allan@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | sfc: Get port number from CS_PORT_NUM, not PCI function numberBen Hutchings2010-06-03
| | | | | | | | | | | | | | | | | | | | | | | | A single shared memory region used to communicate with firmware is mapped into both PCI PFs of the SFC9020 and SFL9021. Drivers must be able to identify which port they are addressing in order to use the correct sub-region. Currently we use the PCI function number, but the PCI address may be virtualised. Use the CS_PORT_NUM register field defined for just this purpose. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | cls_u32: use skb_header_pointer() to dereference data safelyChangli Gao2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | use skb_header_pointer() to dereference data safely the original skb->data dereference isn't safe, as there isn't any skb->len or skb_is_nonlinear() check. skb_header_pointer() is used instead in this patch. And when the skb isn't long enough, we terminate the function u32_classify() immediately with -1. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCP: tcp_hybla: Fix integer overflow in slow start incrementDaniele Lacamera2010-06-02
| | | | | | | | | | | | | | For large values of rtt, 2^rho operation may overflow u32. Clamp down the increment to 2^16. Signed-off-by: Daniele Lacamera <root@danielinux.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | act_nat: fix the wrong checksum when addr isn't in old_addr/maskChangli Gao2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | fix the wrong checksum when addr isn't in old_addr/mask For TCP and UDP packets, when addr isn't in old_addr/mask we don't do SNAT or DNAT, and we should not update layer 4 checksum. Signed-off-by: Changli Gao <xiaosuo@gmail.com> ---- net/sched/act_nat.c | 4 ++++ 1 file changed, 4 insertions(+) Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/fec: fix pm to survive to suspend/resumeEric Bénard2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | * in the actual driver, calling fec_stop and fec_enet_init doesn't allow to have a working network interface at resume (where a ifconfig down and up is required to recover the interface) * by using fec_enet_close and fec_enet_open, this patch solves this problem and handle the case where the link changed between suspend and resume * this patch also disable clock at suspend and reenable it at resume Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | korina: count RX DMA OVR as rx_fifo_errorPhil Sutter2010-06-02
| | | | | | | | | | | | | | | | | | This way, RX DMA overruns (actually being caused by overrun of the 512byte input FIFO) show up in ifconfig output. The rx_fifo_errors counter is unused otherwise. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
* | korina: use netdev_alloc_skb_ip_align() here, tooPhil Sutter2010-06-02
| | | | | | | | | | | | | | | | This patch completes commit 89d71a66c40d629e3b1285def543ab1425558cd5 which missed this spot, as it seems. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
* | korina: fix deadlock on RX FIFO overrunPhil Sutter2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By calling korina_restart(), the IRQ handler tries to disable the interrupt it's currently serving. This leads to a deadlock since disable_irq() waits for any running IRQ handlers to finish before returning. This patch addresses the issue by turning korina_restart() into a workqueue task, which is then scheduled when needed. Reproducing the deadlock is easily done using e.g. GNU netcat to send large amounts of UDP data to the host running this driver. Note that the same problem (and fix) applies to TX FIFO underruns, but apparently these are less easy to trigger. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: fix conflict between null_or_orig and null_or_bondJohn Fastabend2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a skb is received on an inactive bond that does not meet the special cases checked for by skb_bond_should_drop it should only be delivered to exact matches as the comment in netif_receive_skb() says. However because null_or_bond could also be null this is not always true. This patch renames null_or_bond to orig_or_bond and initializes it to orig_dev. This keeps the intent of null_or_bond to pass frames received on VLAN interfaces stacked on bonding interfaces without invalidating the statement for null_or_orig. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: init_vlan should not copy slave or master flagsJohn Fastabend2010-06-02
| | | | | | | | | | | | | | | | | | The vlan device should not copy the slave or master flags from the real device. It is not in the bond until added nor is it a master. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | enic: bug fix: make the set/get netlink VF_PORT support symmetricalScott Feldman2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | To make get/set netlink VF_PORT truly symmetrical, we need to keep track of what items are set and only return those items on get. Previously, the driver wasn't differentiating between a set of attr with a NULL string, for example, and not setting the attr at all. We only want to return the NULL string if the attr was actually set with a NULL string. Otherwise, don't return the attr. Signed-off-by: Scott Feldman <scofeldm@cisco.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | bnx2: Fix hang during rmmod bnx2.Michael Chan2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The regression is caused by: commit 4327ba435a56ada13eedf3eb332e583c7a0586a9 bnx2: Fix netpoll crash. If ->open() and ->close() are called multiple times, the same napi structs will be added to dev->napi_list multiple times, corrupting the dev->napi_list. This causes free_netdev() to hang during rmmod. We fix this by calling netif_napi_del() during ->close(). Also, bnx2_init_napi() must not be in the __devinit section since it is called by ->open(). Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Benjamin Li <benli@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | xfrm: force a dst reference in __xfrm_route_forward()Eric Dumazet2010-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | Packets going through __xfrm_route_forward() have a not refcounted dst entry, since we enabled a noref forwarding path. xfrm_lookup() might incorrectly release this dst entry. It's a bit late to make invasive changes in xfrm_lookup(), so lets force a refcount in this path. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | drivers/isdn/hardware/mISDN: Use GFP_ATOMIC when a lock is heldJulia Lawall2010-06-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function inittiger is only called from nj_init_card, where a lock is held. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @gfp exists@ identifier fn; position p; @@ fn(...) { ... when != spin_unlock_irqrestore when any GFP_KERNEL@p ... when any } @locked@ identifier gfp.fn; @@ spin_lock_irqsave(...) ... when != spin_unlock_irqrestore fn(...) @depends on locked@ position gfp.p; @@ - GFP_KERNEL@p + GFP_ATOMIC // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ksz884x: Add missing validate_addr hookDenis Kirjanov2010-06-01
| | | | | | | | | | | | | | Add missing validate_addr hook Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ksz884x: convert to netdev_tx_tDenis Kirjanov2010-06-01
| | | | | | | | | | | | | | Convert TX hook to netdev_tx_t type Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | virtio-net: pass gfp to add_bufMichael S. Tsirkin2010-06-01
| | | | | | | | | | | | | | | | | | | | | | | | virtio-net bounces buffer allocations off to a thread if it can't allocate buffers from the atomic pool. However, if posting buffers still requires atomic buffers, this is unlikely to succeed. Fix by passing in the proper gfp_t parameter. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* | be2net: convert hdr.timeout in be_cmd_loopback_test() to le32Sathya Perla2010-06-01
| | | | | | | | | | | | | | | | The current code fails on ppc as hdr.timeout is not being converted to le32. Signed-off-by: Sathya Perla <sathyap@serverengines.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | can: mpc5xxx_can.c: Fix build failureAnatolij Gustschin2010-06-01
| | | | | | | | | | | | | | | | | | | | Fixes build error caused by the OF device_node pointer being moved into struct device. Signed-off-by: Anatolij Gustschin <agust@denx.de> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/ipv4/tcp_input.c: fix compilation breakage when FASTRETRANS_DEBUG > 1Joe Perches2010-06-01
| | | | | | | | | | | | | | | | Commit: c720c7e8383aff1cb219bddf474ed89d850336e3 missed these. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge branch 'master' of ↵David S. Miller2010-06-01
|\ \ | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6
| * | netfilter: xtables: stackptr should be percpuEric Dumazet2010-05-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f3c5c1bfd4 (netfilter: xtables: make ip_tables reentrant) introduced a performance regression, because stackptr array is shared by all cpus, adding cache line ping pongs. (16 cpus share a 64 bytes cache line) Fix this using alloc_percpu() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-By: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
| * | netfilter: don't xt_jumpstack_alloc twice in xt_register_tableXiaotian Feng2010-05-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In xt_register_table, xt_jumpstack_alloc is called first, later xt_replace_table is used. But in xt_replace_table, xt_jumpstack_alloc will be used again. Then the memory allocated by previous xt_jumpstack_alloc will be leaked. We can simply remove the previous xt_jumpstack_alloc because there aren't any users of newinfo between xt_jumpstack_alloc and xt_replace_table. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Cc: Patrick McHardy <kaber@trash.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Alexey Dobriyan <adobriyan@gmail.com> Acked-By: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
* | | net: sock_queue_err_skb() dont mess with sk_forward_allocEric Dumazet2010-06-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct sk_forward_alloc handling for error_queue would need to use a backlog of frames that softirq handler could not deliver because socket is owned by user thread. Or extend backlog processing to be able to process normal and error packets. Another possibility is to not use mem charge for error queue, this is what I implemented in this patch. Note: this reverts commit 29030374 (net: fix sk_forward_alloc corruptions), since we dont need to lock socket anymore. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | greth: Fix build after OF device conversions.David S. Miller2010-05-31
| | | | | | | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller2010-05-31
|\| |
| * | Linux 2.6.35-rc1Linus Torvalds2010-05-30
| | | | | | | | | | | | .. and thus endeth the merge window.
| * | Merge branch 'slub/urgent' of ↵Linus Torvalds2010-05-30
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'slub/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: SLUB: Allow full duplication of kmalloc array for 390 slub: move kmem_cache_node into it's own cacheline
| | * | SLUB: Allow full duplication of kmalloc array for 390Christoph Lameter2010-05-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 756dee75872a2a764b478e18076360b8a4ec9045 ("SLUB: Get rid of dynamic DMA kmalloc cache allocation") makes S390 run out of kmalloc caches. Increase the number of kmalloc caches to a safe size. Cc: <stable@kernel.org> [ .33 and .34 ] Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| | * | slub: move kmem_cache_node into it's own cachelineAlexander Duyck2010-05-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is meant to improve the performance of SLUB by moving the local kmem_cache_node lock into it's own cacheline separate from kmem_cache. This is accomplished by simply removing the local_node when NUMA is enabled. On my system with 2 nodes I saw around a 5% performance increase w/ hackbench times dropping from 6.2 seconds to 5.9 seconds on average. I suspect the performance gain would increase as the number of nodes increases, but I do not have the data to currently back that up. Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713 Cc: <stable@kernel.org> Reported-by: Alex Shi <alex.shi@intel.com> Tested-by: Alex Shi <alex.shi@intel.com> Acked-by: Yanmin Zhang <yanmin_zhang@linux.intel.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
| * | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2010-05-30
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mutex: Fix optimistic spinning vs. BKL
| | * | | mutex: Fix optimistic spinning vs. BKLTony Breeds2010-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we can hit a nasty case with optimistic spinning on mutexes: CPU A tries to take a mutex, while holding the BKL CPU B tried to take the BLK while holding the mutex This looks like a AB-BA scenario but in practice, is allowed and happens due to the auto-release on schedule() nature of the BKL. In that case, the optimistic spinning code can get us into a situation where instead of going to sleep, A will spin waiting for B who is spinning waiting for A, and the only way out of that loop is the need_resched() test in mutex_spin_on_owner(). This patch fixes it by completely disabling spinning if we own the BKL. This adds one more detail to the extensive list of reasons why it's a bad idea for kernel code to be holding the BKL. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: <stable@kernel.org> LKML-Reference: <20100519054636.GC12389@ozlabs.org> [ added an unlikely() attribute to the branch ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2010-05-30
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tui: Fix last use_browser problem related to .perfconfig perf symbols: Add the build id cache to the vmlinux path perf tui: Reset use_browser if stdout is not a tty ring-buffer: Move zeroing out excess in page to ring buffer code ring-buffer: Reset "real_end" when page is filled
| | * \ \ \ Merge branch 'tip/perf/core' of ↵Ingo Molnar2010-05-29
| | |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
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