Streamline the large uv_flush_send_and_wait() function by use of
a couple of helper functions.
And remove some excess comments.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004ay-IH@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the Broadcast Assist Unit driver use the BAU for TLB
shootdowns of cpu's on the local uvhub.
It was previously thought that IPI might be faster to the cpu's
on the local hub. But the IPI operation would have to follow
the completion of the BAU broadcast anyway. So we broadcast to
the local uvhub in all cases except when the current cpu was the
only local cpu in the mask.
This simplifies uv_flush_send_and_wait() in that it returns
either all shootdowns complete, or none.
Adjust the statistics to account for shootdowns on the local
uvhub.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004aq-G7@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove a faulty assumption that a long running BAU request has
encountered a hardware problem and will never finish.
Numalink congestion can make a request appear to have
encountered such a problem, but it is not safe to cancel the
request. If such a cancel is done but a reply is later received
we can miss a TLB shootdown.
We depend upon the max_bau_concurrent 'throttle' to prevent the
stay-busy case from happening.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004ad-BV@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move some structure definitions from the C code to the BAU
header file, and change the organization of that header file a
little.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004aI-54@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use a pointer from the per-cpu BAU control structure to the
per-cpu BAU statistics structure.
We nearly always know the first before needing the second.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004aB-2k@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The numalink network can become so congested that TLB shootdown
using the Broadcast Assist Unit becomes slower than using IPI's.
In that case, disable the use of the BAU for a period of time.
The period is tunable. When the period expires the use of the
BAU is re-enabled. A count of these actions is added to the
statistics file.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNy-0004a4-0a@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the Broadcast Assist Unit driver's nine tuning values variable by
making them accessible through a read/write debugfs file.
The file will normally be mounted as
/sys/kernel/debug/sgi_uv/bau_tunables. The tunables are kept in each
cpu's per-cpu BAU structure.
The patch also does a little name improvement, and corrects the reset of
two destination timeout counters.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNx-0004Zx-Uo@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Calculate the Broadcast Assist Unit's destination timeout period from the
values in the relevant MMR's.
Store it in each cpu's per-cpu BAU structure so that a destination
timeout can be differentiated from a 'plugged' situation in which all
software ack resources are already allocated and a timeout is pending.
That case returns an immediate destination error.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: gregkh@suse.de
LKML-Reference: <E1OJvNx-0004Zq-RK@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- increase performance of the interrupt handler
- release timed-out software acknowledge resources
- recover from continuous-busy status due to a hardware issue
- add a 'throttle' to keep a uvhub from sending more than a
specified number of broadcasts concurrently (work around the hardware issue)
- provide a 'nobau' boot command line option
- rename 'pnode' and 'node' to 'uvhub' (the 'node' terminology
is ambiguous)
- add some new statistics about the scope of broadcasts, retries, the
hardware issue and the 'throttle'
- split off new function uv_bau_retry_msg() from
uv_bau_process_message() per community coding style feedback.
- simplify the argument list to uv_bau_process_message(), per
community coding style feedback.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: linux-mm@kvack.org
Cc: Jack Steiner <steiner@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <E1O25Z4-0004Ur-PB@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The SGI UV Broadcast Assist Unit is used to send TLB shootdown
messages to remote nodes of the system. The header of the
message must contain the subnode id of the block in the
receiving hub that handles such messages. It should always be
0x10, the id of the "LB" block.
It had previously been documented as a "must be zero" field.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <E1Mc1x7-0005Ce-6t@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The UV tlb shootdown code has a serious initialization error.
An array of structures [32*8] is initialized as if it were [32].
The array is indexed by (cpu number on the blade)*8, so the short
initialization works for up to 4 cpus on a blade.
But above that, we provide an invalid opcode to the hub's
broadcast assist unit.
This patch changes the allocation of the array to use its symbolic
dimensions for better clarity. And initializes all 32*8 entries.
Shortened 'UV_ACTIVATION_DESCRIPTOR_SIZE' to 'UV_ADP_SIZE' per Ingo's
recommendation.
Tested on the UV simulator.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
LKML-Reference: <E1M6lZR-0007kV-Aq@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Make the following uv related cleanups.
* collect visible uv related definitions and interfaces into uv/uv.h
and use it. this cleans up the messy situation where on 64bit, uv
is defined properly, on 32bit generic it's dummy and on the rest
undefined. after this clean up, uv is defined on 64 and dummy on
32.
* update uv_flush_tlb_others() such that it takes cpumask of
to-be-flushed cpus as argument, instead of that minus self, and
returns yet-to-be-flushed cpumask, instead of modifying the passed
in parameter. this interface change will ease dummy implementation
of uv_flush_tlb_others() and makes uv tlb flush related stuff
defined in tlb_uv proper.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: reduce stack usage, use new cpumask API.
This is made a little more tricky by uv_flush_tlb_others which
actually alters its argument, for an IPI to be sent to the remaining
cpus in the mask.
I solve this by allocating a cpumask_var_t for this case and falling back
to IPI should this fail.
To eliminate temporaries in the caller, all flush_tlb_others implementations
now do the this-cpu-elimination step themselves.
Note also the curious "cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask)"
which has been there since pre-git and yet f->flush_cpumask is always zero
at this point.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Drop double underscores from header guards in arch/x86/include. They
are used inconsistently, and are not necessary.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:
a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
