- 29 Jul, 2020 3 commits
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Nicholas Piggin authored
KVM supports msgsndp in guests by trapping and emulating the instruction, so it was decided to always use XIVE for IPIs if it is available. However on PowerVM systems, msgsndp can be used and gives better performance. On large systems, high XIVE interrupt rates can have sub-linear scaling, and using msgsndp can reduce the load on the interrupt controller. So switch to using core local doorbells even if XIVE is available. This reduces performance for KVM guests with an SMT topology by about 50% for ping-pong context switching between SMT vCPUs. An option vector (or dt-cpu-ftrs) could be defined to disable msgsndp to get KVM performance back. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Tested-by:
Cédric Le Goater <clg@kaod.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-3-npiggin@gmail.com
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Nicholas Piggin authored
These are only called in one place for a given platform, so inline them for performance. Signed-off-by:
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Athira Rajeev authored
Commit 9908c826 ("powerpc/perf: Add Power10 PMU feature to DT CPU features") defines MMCRA_BHRB_DISABLE as `0x2000000000UL`. Binutils version less than 2.28 doesn't support UL suffix. arch/powerpc/kernel/cpu_setup_power.S: Assembler messages: arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: junk at end of line, first unrecognized character is `L' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: junk at end of line, first unrecognized character is `L' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: found 'L', expected: ')' arch/powerpc/kernel/cpu_setup_power.S:250: Error: operand out of range (0x0000002000000000 is not between 0xffffffffffff8000 and 0x000000000000ffff) Fix this by wrapping it with the `_UL` macro. Fixes: 9908c826 ("Add Power10 PMU feature to DT CPU features") Suggested-by:
Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reviewed-by:
Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by:
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- 27 Jul, 2020 1 commit
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Michael Ellerman authored
skiroot_defconfig fails: arch/powerpc/kernel/fadump.c:48:17: error: ‘cpus_in_fadump’ defined but not used 48 | static atomic_t cpus_in_fadump; Fix it by moving the definition into the #ifdef where it's used. Fixes: ba608c4f ("powerpc/fadump: fix race between pstore write and fadump crash trigger") Signed-off-by:
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- 26 Jul, 2020 36 commits
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Randy Dunlap authored
Drop the repeated word "for". Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "a". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "in". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "the". Signed-off-by:
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Randy Dunlap authored
Drop the repeated words "file" and "the". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "use". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "per". Signed-off-by:
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Randy Dunlap authored
Drop the repeated word "below". Signed-off-by:
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Li RongQing authored
Align it with other architectures and none of the callers has been interested its return Signed-off-by:
Li RongQing <lirongqing@baidu.com> Signed-off-by:
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Christophe Leroy authored
In note_page(), the pg_state is updated the same way in two places. Add note_page_update_state() to do it. Also include the display of boundary markers there as it is missing "no level" leg, leading to a mismatch when the first two markers are at the same address and the first displayed area uses that address. Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
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Christophe Leroy authored
st->last_pa is always updated in note_page() so it can be done outside the if/elseif/else block. Signed-off-by:
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Christophe Leroy authored
When STRICT_KERNEL_RWX is set, we want to set NX bit on vmalloc segments. But modules require exec. Use a dedicated segment for modules. There is not much space above kernel, and we don't waste vmalloc space to do alignment. Therefore, we take the segment before PAGE_OFFSET for modules. Signed-off-by:
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Christophe Leroy authored
Kernel space starts at TASK_SIZE. Select kernel page table when address is over TASK_SIZE. Signed-off-by:
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Christophe Leroy authored
User space stops at TASK_SIZE. At the moment, kernel space starts at PAGE_OFFSET. In order to use space between TASK_SIZE and PAGE_OFFSET for modules, make TASK_SIZE the limit between user and kernel space. Note that fault.c already considers TASK_SIZE as the boundary between user and kernel space. Signed-off-by:
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Christophe Leroy authored
Instead of leaving NX unset on all segments above the start of vmalloc space, only leave NX unset on segments used for modules. Signed-off-by:
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Christophe Leroy authored
In order to allow allocation of modules outside of vmalloc space, use MODULES_VADDR and MODULES_END when MODULES_VADDR is defined. Redefine module_alloc() when MODULES_VADDR defined. Unmap corresponding KASAN shadow memory. Signed-off-by:
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Christophe Leroy authored
Use is_vmalloc_or_module_addr() instead of is_vmalloc_addr() Signed-off-by:
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Wei Yongjun authored
The sparse tool complains as follows: arch/powerpc/platforms/pseries/papr_scm.c:97:1: warning: symbol 'papr_nd_regions' was not declared. Should it be static? arch/powerpc/platforms/pseries/papr_scm.c:98:1: warning: symbol 'papr_ndr_lock' was not declared. Should it be static? Those variables are not used outside of papr_scm.c, so this commit marks them static. Fixes: 85343a8d ("powerpc/papr/scm: Add bad memory ranges to nvdimm bad ranges") Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by:
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Bill Wendling authored
Clang's objdump emits slightly different output from GNU's objdump, causing a list of warnings to be emitted during relocatable builds. E.g., clang's objdump emits this: c000000000000004: 2c 00 00 48 b 0xc000000000000030 ... c000000000005c6c: 10 00 82 40 bf 2, 0xc000000000005c7c while GNU objdump emits: c000000000000004: 2c 00 00 48 b c000000000000030 <__start+0x30> ... c000000000005c6c: 10 00 82 40 bne c000000000005c7c <masked_interrupt+0x3c> Adjust llvm-objdump's output to remove the extraneous '0x' and convert 'bf' and 'bt' to 'bne' and 'beq' resp. to more closely match GNU objdump's output. Note that clang's objdump doesn't yet output the relocation symbols on PPC. Signed-off-by:
Bill Wendling <morbo@google.com> Signed-off-by:
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Nicholas Piggin authored
This implements smp_cond_load_relaxed() with the slowpath busy loop using the preferred SMT priority pattern. Signed-off-by:
Waiman Long <longman@redhat.com> [mpe: Make it 64-bit only to fix build errors on 32-bit] Signed-off-by:
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Nicholas Piggin authored
This brings the behaviour of the uncontended fast path back to roughly equivalent to simple spinlocks -- a single atomic op with lock hint. Signed-off-by:
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Nicholas Piggin authored
This implements the generic paravirt qspinlocks using H_PROD and H_CONFER to kick and wait. This uses an un-directed yield to any CPU rather than the directed yield to a pre-empted lock holder that paravirtualised simple spinlocks use, that requires no kick hcall. This is something that could be investigated and improved in future. Performance results can be found in the commit which added queued spinlocks. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
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Nicholas Piggin authored
These have shown significantly improved performance and fairness when spinlock contention is moderate to high on very large systems. With this series including subsequent patches, on a 16 socket 1536 thread POWER9, a stress test such as same-file open/close from all CPUs gets big speedups, 11620op/s aggregate with simple spinlocks vs 384158op/s (33x faster), where the difference in throughput between the fastest and slowest thread goes from 7x to 1.4x. Thanks to the fast path being identical in terms of atomics and barriers (after a subsequent optimisation patch), single threaded performance is not changed (no measurable difference). On smaller systems, performance and fairness seems to be generally improved. Using dbench on tmpfs as a test (that starts to run into kernel spinlock contention), a 2-socket OpenPOWER POWER9 system was tested with bare metal and KVM guest configurations. Results can be found here: https://github.com/linuxppc/issues/issues/305#issuecomment-663487453 Observations are: - Queued spinlocks are equal when contention is insignificant, as expected and as measured with microbenchmarks. - When there is contention, on bare metal queued spinlocks have better throughput and max latency at all points. - When virtualised, queued spinlocks are slightly worse approaching peak throughput, but significantly better throughput and max latency at all points beyond peak, until queued spinlock maximum latency rises when clients are 2x vCPUs. The regressions haven't been analysed very well yet, there are a lot of things that can be tuned, particularly the paravirtualised locking, but the numbers already look like a good net win even on relatively small systems. Signed-off-by:
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Nicholas Piggin authored
To prepare for queued spinlocks. This is a simple rename except to update preprocessor guard name and a file reference. Signed-off-by:
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Nicholas Piggin authored
These functions will be used by the queued spinlock implementation, and may be useful elsewhere too, so move them out of spinlock.h. Signed-off-by:
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Srikar Dronamraju authored
MAX_NUMNODES is a theoretical maximum number of nodes thats is supported by the kernel. Device tree properties exposes the number of possible nodes on the current platform. The kernel would detected this and would use it for most of its resource allocations. If the platform now increases the nodes to over what was already exposed, then it may lead to inconsistencies. Hence limit it to the already exposed nodes. Suggested-by:
Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by:
Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by:
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Finn Thain authored
The function prototype correctly specifies the 'static' storage class. Let the function definition match the declaration for better readability. Signed-off-by:
Finn Thain <fthain@telegraphics.com.au> Signed-off-by:
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Finn Thain authored
The adb_request struct can be stored on the stack because the request is synchronous and is completed before the function returns. Signed-off-by:
Stan Johnson <userm57@yahoo.com> Signed-off-by:
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Finn Thain authored
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Finn Thain authored
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Finn Thain authored
Userspace applications may use /dev/adb to send Talk requests. Such requests always have req->reply_expected == 1. The same is true of Talk requests sent by the kernel, except for poll requests queued internally by the via-macii driver. Those requests have req->reply_expected == 0. Consequently, poll reply packets get treated like autopoll reply packets. (It doesn't make sense to try to distinguish them.) Always enter 'reading' state after a poll request, so that the reply gets collected and passed to adb_input(), and none go missing. All Talk replies passed to adb_input() come from polling or autopolling, so call adb_input() with the autopoll parameter set to 1. Fixes: d95fd5fc ("m68k: Mac II ADB fixes") # v5.0+ Signed-off-by:
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Finn Thain authored
The driver state machine may enter the 'read_done' state when leaving the 'idle' or 'reading' state. This transition is pointless, as is the extra interrupt it requires. The interrupt is produced by the transceiver (even when it has no data to send) because an extra EVEN/ODD toggle was signalled by the driver. Drop the extra state to simplify the code. Fixes: 1da177e4 ("Linux-2.6.12-rc2") # v5.0+ Signed-off-by:
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Finn Thain authored
I'm told that the /CTLR_IRQ signal from the ADB transceiver gets interpreted by MacOS to mean SRQ, bus timeout or end-of-packet depending on the circumstances, and that Linux's via-macii driver does not correctly interpret this signal. Instead, the via-macii driver interprets certain received byte values (0x00 and 0xFF) as signalling end of packet and bus timeout (respectively). Problem is, those values can also appear under other circumstances. This patch changes the bus timeout, end of packet and SRQ detection logic to bring it closer to the logic that MacOS reportedly uses. Fixes: 1da177e4 ("Linux-2.6.12-rc2") # v5.0+ Reported-by:
Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Signed-off-by:
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Finn Thain authored
Poll the most recently polled device by default, rather than the lowest device address that happens to be enabled in autopoll_devs. This improves input latency. Re-use macii_queue_poll() rather than duplicate that logic. This eliminates a static struct and function. Fixes: d95fd5fc ("m68k: Mac II ADB fixes") # v5.0+ Signed-off-by:
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Finn Thain authored
The interrupt handler should be excluded when accessing the autopoll_devs variable. Fixes: d95fd5fc ("m68k: Mac II ADB fixes") # v5.0+ Signed-off-by:
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