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2010-09-08RDS: Implement masked atomic operationsAndy Grover
Add two CMSGs for masked versions of cswp and fadd. args struct modified to use a union for different atomic op type's arguments. Change IB to do masked atomic ops. Atomic op type in rds_message similarly unionized. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08rds: fix rds_send_xmit() serializationZach Brown
rds_send_xmit() was changed to hold an interrupt masking spinlock instead of a mutex so that it could be called from the IB receive tasklet path. This broke the TCP transport because its xmit method can block and masks and unmasks interrupts. This patch serializes callers to rds_send_xmit() with a simple bit instead of the current spinlock or previous mutex. This enables rds_send_xmit() to be called from any context and to call functions which block. Getting rid of the c_send_lock exposes the bare c_lock acquisitions which are changed to block interrupts. A waitqueue is added so that rds_conn_shutdown() can wait for callers to leave rds_send_xmit() before tearing down partial send state. This lets us get rid of c_senders. rds_send_xmit() is changed to check the conn state after acquiring the RDS_IN_XMIT bit to resolve races with the shutdown path. Previously both worked with the conn state and then the lock in the same order, allowing them to race and execute the paths concurrently. rds_send_reset() isn't racing with rds_send_xmit() now that rds_conn_shutdown() properly ensures that rds_send_xmit() can't start once the conn state has been changed. We can remove its previous use of the spinlock. Finally, c_send_generation is redundant. Callers can race to test the c_flags bit by simply retrying instead of racing to test the c_send_generation atomic. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: remove unused rds_send_acked_before()Zach Brown
rds_send_acked_before() wasn't blocking interrupts when acquiring c_lock from user context but nothing calls it. Rather than fix its use of c_lock we just remove the function. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08RDS: introduce rds_conn_connect_if_down()Zach Brown
A few paths had the same block of code to queue a connection's connect work if it was in the right state. Let's move this in to a helper function. Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08rds: Fix reference counting on the for xmit_atomic and xmit_rdmaChris Mason
This makes sure we have the proper number of references in rds_ib_xmit_atomic and rds_ib_xmit_rdma. We also consistently drop references the same way for all message types as the IOs end. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: Fix RDMA message reference countingChris Mason
The RDS send_xmit code was trying to get fancy with message counting and was dropping the final reference on the RDMA messages too early. This resulted in memory corruption and oopsen. The fix here is to always add a ref as the parts of the message passes through rds_send_xmit, and always drop a ref as the parts of the message go through completion handling. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08rds: don't let RDS shutdown a connection while senders are presentChris Mason
This is the first in a long line of patches that tries to fix races between RDS connection shutdown and RDS traffic. Here we are maintaining a count of active senders to make sure the connection doesn't go away while they are using it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08RDS: Update comments in rds_send_xmit()Andy Grover
Update comments to reflect changes in previous commit. Keeping as separate commits due to different authorship. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Use a generation counter to avoid rds_send_xmit loopChris Mason
rds_send_xmit is required to loop around after it releases the lock because someone else could done a trylock, found someone working on the list and backed off. But, once we drop our lock, it is possible that someone else does come in and make progress on the list. We should detect this and not loop around if another process is actually working on the list. This patch adds a generation counter that is bumped every time we get the lock and do some send work. If the retry notices someone else has bumped the generation counter, it does not need to loop around and continue working. Signed-off-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Get pong working againAndy Grover
Call send_xmit() directly from pong() Set pongs as op_active Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Remove send_quota from send_xmit()Andy Grover
The purpose of the send quota was really to give fairness when different connections were all using the same workq thread to send backlogged msgs -- they could only send so many before another connection could make progress. Now that each connection is pushing the backlog from its completion handler, they are all guaranteed to make progress and the quota isn't needed any longer. A thread *will* have to send all previously queued data, as well as any further msgs placed on the queue while while c_send_lock was held. In a pathological case a single process can get roped into doing this for long periods while other threads get off free. But, since it can only do this until the transport reports full, this is a bounded scenario. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Fix locking in send on m_rs_lockAndy Grover
Do not nest m_rs_lock under c_lock Disable interrupts in {rdma,atomic}_send_complete Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Call rds_send_xmit() directly from sendmsg()Andy Grover
rds_sendmsg() is calling the send worker function to send the just-queued datagrams, presumably because it wants the behavior where anything not sent will re-call the send worker. We now ensure all queued datagrams are sent by retrying from the send completion handler, so this isn't needed any more. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: rds_send_xmit() locking/irq fixesAndy Grover
rds_message_put() cannot be called with irqs off, so move it after irqs are re-enabled. Spinlocks throughout the function do not to use _irqsave because the lock of c_send_lock at top already disabled irqs. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Change send lock from a mutex to a spinlockAndy Grover
This change allows us to call rds_send_xmit() from a tasklet, which is crucial to our new operating model. * Change c_send_lock to a spinlock * Update stats fields "sem_" to "_lock" * Remove unneeded rds_conn_is_sending() About locking between shutdown and send -- send checks if the connection is up. Shutdown puts the connection into DISCONNECTING. After this, all threads entering send will exit immediately. However, a thread could be *in* send_xmit(), so shutdown acquires the c_send_lock to ensure everyone is out before proceeding with connection shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Stop supporting old cong map sending methodAndy Grover
We now ask the transport to give us a rm for the congestion map, and then we handle it normally. Previously, the transport defined a function that we would call to send a congestion map. Convert TCP and loop transports to new cong map method. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Perform unmapping ops in stagesAndy Grover
Previously, RDS would wait until the final send WR had completed and then handle cleanup. With silent ops, we do not know if an atomic, rdma, or data op will be last. This patch handles any of these cases by keeping a pointer to the last op in the message in m_last_op. When the TX completion event fires, rds dispatches to per-op-type cleanup functions, and then does whole-message cleanup, if the last op equalled m_last_op. This patch also moves towards having op-specific functions take the op struct, instead of the overall rm struct. rds_ib_connection has a pointer to keep track of a a partially- completed data send operation. This patch changes it from an rds_message pointer to the narrower rm_data_op pointer, and modifies places that use this pointer as needed. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Make sure cmsgs aren't used in improper waysAndy Grover
It hasn't cropped up in the field, but this code ensures it is impossible to issue operations that pass an rdma cookie (DEST, MAP) in the same sendmsg call that's actually initiating rdma or atomic ops. Disallowing this perverse-but-technically-allowed usage makes silent RDMA heuristics slightly easier. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Add flag for silent ops. Do atomic op before RDMAAndy Grover
Add a flag to the API so users can indicate they want silent operations. This is needed because silent ops cannot be used with USE_ONCE MRs, so we can't just assume silent. Also, change send_xmit to do atomic op before rdma op if both are present, and centralize the hairy logic to determine if we want to attempt silent, or not. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: queue failure notifications for dropped atomic opsAndy Grover
When dropping ops in the send queue, we notify the client of failed rdma ops they asked for notifications on, but not atomic ops. It should be for both. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Do not set op_active in r_m_copy_from_user().Andy Grover
Do not allocate sgs for data for 0-length datagrams Set data.op_active in rds_sendmsg() instead of rds_message_copy_from_user(). Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Rewrite rds_send_xmitAndy Grover
Simplify rds_send_xmit(). Send a congestion map (via xmit_cong_map) without decrementing send_quota. Move resetting of conn xmit variables to end of loop. Update comments. Implement a special case to turn off sending an rds header when there is an atomic op and no other data. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Rename data op members prefix from m_ to op_Andy Grover
For consistency. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Remove struct rds_rdma_opAndy Grover
A big changeset, but it's all pretty dumb. struct rds_rdma_op was already embedded in struct rm_rdma_op. Remove rds_rdma_op and put its members in rm_rdma_op. Rename members with "op_" prefix instead of "r_", for consistency. Of course this breaks a lot, so fixup the code accordingly. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Implement silent atomicsAndy Grover
Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: WhitespaceAndy Grover
Tidy up some whitespace issues. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Implement atomic operationsAndy Grover
Implement a CMSG-based interface to do FADD and CSWP ops. Alter send routines to handle atomic ops. Add atomic counters to stats. Add xmit_atomic() to struct rds_transport Inline rds_ib_send_unmap_rdma into unmap_rm Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Clear up some confusing code in send_remove_from_sockAndy Grover
The previous code was correct, but made the assumption that if r_notifier was non-NULL then either r_recverr or r_notify was true. Valid, but fragile. Changed to explicitly check r_recverr (shows up in greps for recverr now, too.) Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: make m_rdma_op a member of rds_messageAndy Grover
This eliminates a separate memory alloc, although it is now necessary to add an "r_active" flag, since it is no longer to use the m_rdma_op pointer as an indicator of if an rdma op is present. rdma SGs allocated from rm sg pool. rds_rm_size also gets bigger. It's a little inefficient to run through CMSGs twice, but it makes later steps a lot smoother. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: fold rdma.h into rds.hAndy Grover
RDMA is now an intrinsic part of RDS, so it's easier to just have a single header. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Explicitly allocate rm in sendmsg()Andy Grover
r_m_copy_from_user used to allocate the rm as well as kernel buffers for the data, and then copy the data in. Now, sendmsg() allocates the rm, although the data buffer alloc still happens in r_m_copy_from_user. SGs are still allocated with rm, but now r_m_alloc_sgs() is used to reserve them. This allows multiple SG lists to be allocated from the one rm -- this is important once we also want to alloc our rdma sgl from this pool. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: break out rdma and data ops into nested structs in rds_messageAndy Grover
Clearly separate rdma-related variables in rm from data-related ones. This is in anticipation of adding atomic support. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: cleanup: remove "== NULL"s and "!= NULL"s in ptr comparisonsAndy Grover
Favor "if (foo)" style over "if (foo != NULL)". Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Fix locking in send on m_rs_lockAndy Grover
Do not nest m_rs_lock under c_lock Disable interrupts in {rdma,atomic}_send_complete Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08RDS: Rewrite rds_send_drop_to() for clarityAndy Grover
This function has been the source of numerous bugs; it's just too complicated. Simplified to nest spinlocks cleanly within the second loop body, and kick out early if there are no rms to drop. This will be a little slower because conn lock is grabbed for each entry instead of "caching" the lock across rms, but this should be entirely irrelevant to fastpath performance. Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-04-20net: sk_sleep() helperEric Dumazet
Define a new function to return the waitqueue of a "struct sock". static inline wait_queue_head_t *sk_sleep(struct sock *sk) { return sk->sk_sleep; } Change all read occurrences of sk_sleep by a call to this function. Needed for a future RCU conversion. sk_sleep wont be a field directly available. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/stmmac/stmmac_main.c drivers/net/wireless/wl12xx/wl1271_cmd.c drivers/net/wireless/wl12xx/wl1271_main.c drivers/net/wireless/wl12xx/wl1271_spi.c net/core/ethtool.c net/mac80211/scan.c
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-16RDS: Do not call set_page_dirty() with irqs offAndy Grover
set_page_dirty() unconditionally re-enables interrupts, so if we call it with irqs off, they will be on after the call, and that's bad. This patch moves the call after we've re-enabled interrupts in send_drop_to(), so it's safe. Also, add BUG_ONs to let us know if we ever do call set_page_dirty with interrupts off. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16RDS: only put sockets that have seen congestion on the poll_waitqAndy Grover
rds_poll_waitq's listeners will be awoken if we receive a congestion notification. Bad performance may result because *all* polled sockets contend for this single lock. However, it should not be necessary to wake pollers when a congestion update arrives if they have never experienced congestion, and not putting these on the waitq will hopefully greatly reduce contention. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16RDS: Fix locking in rds_send_drop_to()Tina Yang
It seems rds_send_drop_to() called __rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED) with only rds_sock lock, but not rds_message lock. It raced with other threads that is attempting to modify the rds_message as well, such as from within rds_rdma_send_complete(). Signed-off-by: Tina Yang <tina.yang@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16RDS: Fix send locking issueTina Yang
Fix a deadlock between rds_rdma_send_complete() and rds_send_remove_from_sock() when rds socket lock and rds message lock are acquired out-of-order. Signed-off-by: Tina Yang <Tina.Yang@oracle.com> Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16RDS: sendmsg() should check sndtimeo, not rcvtimeoAndy Grover
Most likely cut n paste error - sendmsg() was checking sock_rcvtimeo. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-29net: Move && and || to end of previous lineJoe Perches
Not including net/atm/ Compiled tested x86 allyesconfig only Added a > 80 column line or two, which I ignored. Existing checkpatch plaints willfully, cheerfully ignored. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23RDS: Export symbols from core RDSAndy Grover
Now that rdma and tcp transports will be modularized, we need to export a number of functions so they can call them. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-09RDS: Establish connection before parsing CMSGsAndy Grover
The first message to a remote node should prompt a new connection. Even an RDMA op via CMSG. Therefore move CMSG parsing to after connection establishment. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02RDS: Fix m_rs_lock deadlockAndy Grover
rs_send_drop_to() is called during socket close. If it takes m_rs_lock without disabling interrupts, then rds_send_remove_from_sock() can run from the rx completion handler and thus deadlock. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-26RDS: send.cAndy Grover
This is the code to send an RDS datagram. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>