- 24 Apr, 2024 1 commit
-
-
Vincent Guittot authored
sg_overloaded is used instead of sg_overutilized to update rd->sg_overutilized. Fixes: 4475cd8b ("sched/balancing: Simplify the sg_status bitmask and use separate ->overloaded and ->overutilized flags") Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240404155738.2866102-1-vincent.guittot@linaro.org
-
- 17 Apr, 2024 5 commits
-
-
Alexander Gordeev authored
There is no architecture-specific code or data left that generic <linux/vtime.h> needs to know about. Thus, avoid the inclusion of <asm/vtime.h> header. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/f7cd245668b9ae61a55184871aec494ec9199c4a.1712760275.git.agordeev@linux.ibm.com
-
Alexander Gordeev authored
update_timer_sys() and update_timer_mcck() are inlines used for CPU time accounting from the interrupt and machine-check handlers. These routines are specific to s390 architecture, but included via <linux/vtime.h> header implicitly. Avoid the extra loop and include <asm/vtime.h> header directly. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/3fb696637c0eb7e9d6ffd6cbf9e647d7c5986b3d.1712760275.git.agordeev@linux.ibm.com
-
Alexander Gordeev authored
__ARCH_HAS_VTIME_TASK_SWITCH macro is not used anymore. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/b1055852eab0ffea33ad16c92d6a825c83037c3e.1712760275.git.agordeev@linux.ibm.com
-
Alexander Gordeev authored
The generic vtime_task_switch() implementation gets built only if __ARCH_HAS_VTIME_TASK_SWITCH is not defined, but requires an architecture to implement arch_vtime_task_switch() callback at the same time, which is confusing. Further, arch_vtime_task_switch() is implemented for 32-bit PowerPC architecture only and vtime_task_switch() generic variant is rather superfluous. Simplify the whole vtime_task_switch() wiring by moving the existing generic implementation to PowerPC. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2cb6e3caada93623f6d4f78ad938ac6cd0e2fda8.1712760275.git.agordeev@linux.ibm.com
-
Alexander Gordeev authored
Callback arch_vtime_task_switch() is only defined when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is selected. Yet, the function prototype forward declaration is present for CONFIG_VIRT_CPU_ACCOUNTING_GEN variant. Remove it. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/783d7c611864f82b0fb9edf01890b9396f3a549a.1712760275.git.agordeev@linux.ibm.com
-
- 29 Mar, 2024 1 commit
-
-
Ingo Molnar authored
sched/balancing: Simplify the sg_status bitmask and use separate ->overloaded and ->overutilized flags SG_OVERLOADED and SG_OVERUTILIZED flags plus the sg_status bitmask are an unnecessary complication that only make the code harder to read and slower. We only ever set them separately: thule:~/tip> git grep SG_OVER kernel/sched/ kernel/sched/fair.c: set_rd_overutilized_status(rq->rd, SG_OVERUTILIZED); kernel/sched/fair.c: *sg_status |= SG_OVERLOADED; kernel/sched/fair.c: *sg_status |= SG_OVERUTILIZED; kernel/sched/fair.c: *sg_status |= SG_OVERLOADED; kernel/sched/fair.c: set_rd_overloaded(env->dst_rq->rd, sg_status & SG_OVERLOADED); kernel/sched/fair.c: sg_status & SG_OVERUTILIZED); kernel/sched/fair.c: } else if (sg_status & SG_OVERUTILIZED) { kernel/sched/fair.c: set_rd_overutilized_status(env->dst_rq->rd, SG_OVERUTILIZED); kernel/sched/sched.h:#define SG_OVERLOADED 0x1 /* More than one runnable task on a CPU. */ kernel/sched/sched.h:#define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ kernel/sched/sched.h: set_rd_overloaded(rq->rd, SG_OVERLOADED); And use them separately, which results in suboptimal code: /* update overload indicator if we are at root domain */ set_rd_overloaded(env->dst_rq->rd, sg_status & SG_OVERLOADED); /* Update over-utilization (tipping point, U >= 0) indicator */ set_rd_overutilized_status(env->dst_rq->rd, Introduce separate sg_overloaded and sg_overutilized flags in update_sd_lb_stats() and its lower level functions, and change all of them to 'bool'. Remove the now unused SG_OVERLOADED and SG_OVERUTILIZED flags. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Shrikanth Hegde <sshegde@linux.ibm.com> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Qais Yousef <qyousef@layalina.io> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/ZgVPhODZ8/nbsqbP@gmail.com
-
- 28 Mar, 2024 7 commits
-
-
Ingo Molnar authored
The _status() postfix has no real meaning, simplify the naming and harmonize it with set_rd_overloaded(). Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Qais Yousef <qyousef@layalina.io> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/ZgVHq65XKsOZpfgK@gmail.com
-
Ingo Molnar authored
Follow the rename of the root_domain::overloaded flag. Note that this also matches the SG_OVERUTILIZED flag better. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Qais Yousef <qyousef@layalina.io> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/ZgVHq65XKsOZpfgK@gmail.com
-
Ingo Molnar authored
Follow the rename of the root_domain::overloaded flag. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Qais Yousef <qyousef@layalina.io> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/ZgVHq65XKsOZpfgK@gmail.com
-
Ingo Molnar authored
It is silly to use an ambiguous noun instead of a clear adjective when naming such a flag ... Note how root_domain::overutilized already used a proper adjective. rd->overloaded is now set to 1 when the root domain is overloaded. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Qais Yousef <qyousef@layalina.io> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/ZgVHq65XKsOZpfgK@gmail.com
-
Shrikanth Hegde authored
Introduce two helper functions to access & set the root_domain::overload flag: get_rd_overload() set_rd_overload() To make sure code is always following READ_ONCE()/WRITE_ONCE() access methods. No change in functionality intended. [ mingo: Renamed the accessors to get_/set_rd_overload(), tidied up the changelog. ] Suggested-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240325054505.201995-3-sshegde@linux.ibm.com
-
Shrikanth Hegde authored
The root_domain::overload flag is 1 when there's any rq in the root domain that has 2 or more running tasks. (Ie. it's overloaded.) The root_domain structure itself is a global structure per cpuset island. The ::overload flag is maintained the following way: - Set when adding a second task to the runqueue. - It is cleared in update_sd_lb_stats() during load balance, if none of the rqs have 2 or more running tasks. This flag is used during newidle balance to see if its worth doing a full load balance pass, which can be an expensive operation. If it is set, then newidle balance will try to aggressively pull a task. Since commit: 630246a0 ("sched/fair: Clean-up update_sg_lb_stats parameters") ::overload is being written unconditionally, even if it has the same value. The change in value of this depends on the workload, but on typical workloads, it doesn't change all that often: a system is either dominantly overloaded for substantial amounts of time, or not. Extra writes to this semi-global structure cause unnecessary overhead, extra bus traffic, etc. - so avoid it as much as possible. Perf probe stats show that it's worth making this change (numbers are with patch applied): 1M probe:sched_balance_newidle_L38 139 probe:update_sd_lb_stats_L53 <====== 1->0 writes 129K probe:add_nr_running_L12 74 probe:add_nr_running_L13 <====== 0->1 writes 54K probe:update_sd_lb_stats_L50 <====== reads These numbers prove that actual change in the ::overload value is (much) less frequent: L50 is much larger at ~54,000 accesses vs L53+L13 of 139+74. [ mingo: Rewrote the changelog. ] Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Cc: Mel Gorman <mgorman@suse.de> Link: https://lore.kernel.org/r/20240325054505.201995-2-sshegde@linux.ibm.com
-
Shrikanth Hegde authored
Access to root_domainoverutilized is always used with sched_energy_enabled in the pattern: if (sched_energy_enabled && !overutilized) do something So modify the helper function to utilize this pattern. This is more readable code as it would say, do something when root domain is not overutilized. This function always return true when EAS is disabled. No change in functionality intended. Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240326152616.380999-1-sshegde@linux.ibm.com
-
- 26 Mar, 2024 3 commits
-
-
Shrikanth Hegde authored
newidle(CPU_NEWLY_IDLE) balancing doesn't stop the load-balancing if the continue_balancing flag is reset, but the other two balancing (IDLE, BUSY) cases do that. newidle balance stops the load balancing if rq has a task or there is wakeup pending. The same checks are present in should_we_balance for newidle. Hence use the return value and simplify continue_balancing mechanism for newidle. Update the comment surrounding it as well. No change in functionality intended. Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20240325153926.274284-1-sshegde@linux.ibm.com
-
Shrikanth Hegde authored
The root_domain::overutilized field is READ_ONCE() accessed in multiple places, which could be simplified with a helper function. This might also make it more apparent that it needs to be used only in case of EAS. No change in functionality intended. Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240307085725.444486-3-sshegde@linux.ibm.com
-
Shrikanth Hegde authored
root_domain::overutilized is only used for EAS(energy aware scheduler) to decide whether to do load balance or not. It is not used if EAS not possible. Currently enqueue_task_fair and task_tick_fair accesses, sometime updates this field. In update_sd_lb_stats it is updated often. This causes cache contention due to true sharing and burns a lot of cycles. ::overload and ::overutilized are part of the same cacheline. Updating it often invalidates the cacheline. That causes access to ::overload to slow down due to false sharing. Hence add EAS check before accessing/updating this field. EAS check is optimized at compile time or it is a static branch. Hence it shouldn't cost much. With the patch, both enqueue_task_fair and newidle_balance don't show up as hot routines in perf profile. 6.8-rc4: 7.18% swapper [kernel.vmlinux] [k] enqueue_task_fair 6.78% s [kernel.vmlinux] [k] newidle_balance +patch: 0.14% swapper [kernel.vmlinux] [k] enqueue_task_fair 0.00% swapper [kernel.vmlinux] [k] newidle_balance While at it: trace_sched_overutilized_tp expect that second argument to be bool. So do a int to bool conversion for that. Fixes: 2802bf3c ("sched/fair: Add over-utilization/tipping point indicator") Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Qais Yousef <qyousef@layalina.io> Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240307085725.444486-2-sshegde@linux.ibm.com
-
- 25 Mar, 2024 5 commits
-
-
Qais Yousef authored
It is not necessarily an indication of the system being busy and requires a backoff of the load balancer activities. But pushing it high could mean generally delaying other misfit activities or other type of imbalances. Also don't pollute nr_balance_failed because of misfit failures. The value is used for enabling cache hot migration and in migrate_util/load types. None of which should be impacted (skewed) by misfit failures. Signed-off-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240324004552.999936-5-qyousef@layalina.io
-
Qais Yousef authored
The value is no longer used as we now keep track of max_allowed_capacity for each task instead. Signed-off-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240324004552.999936-4-qyousef@layalina.io
-
Qais Yousef authored
If a misfit task is affined to a subset of the possible CPUs, we need to verify that one of these CPUs can fit it. Otherwise the load balancer code will continuously trigger needlessly leading the balance_interval to increase in return and eventually end up with a situation where real imbalances take a long time to address because of this impossible imbalance situation. This can happen in Android world where it's common for background tasks to be restricted to little cores. Similarly if we can't fit the biggest core, triggering misfit is pointless as it is the best we can ever get on this system. To be able to detect that; we use asym_cap_list to iterate through capacities in the system to see if the task is able to run at a higher capacity level based on its p->cpus_ptr. We do that when the affinity change, a fair task is forked, or when a task switched to fair policy. We store the max_allowed_capacity in task_struct to allow for cheap comparison in the fast path. Improve check_misfit_status() function by removing redundant checks. misfit_task_load will be 0 if the task can't move to a bigger CPU. And nohz_balancer_kick() already checks for cpu_check_capacity() before calling check_misfit_status(). Test: ===== Add trace_printk("balance_interval = %lu\n", interval) in get_sd_balance_interval(). run if [ "$MASK" != "0" ]; then adb shell "taskset -a $MASK cat /dev/zero > /dev/null" fi sleep 10 // parse ftrace buffer counting the occurrence of each valaue Where MASK is either: * 0: no busy task running * 1: busy task is pinned to 1 cpu; handled today to not cause misfit * f: busy task pinned to little cores, simulates busy background task, demonstrates the problem to be fixed Results: ======== Note how occurrence of balance_interval = 128 overshoots for MASK = f. BEFORE ------ MASK=0 1 balance_interval = 175 120 balance_interval = 128 846 balance_interval = 64 55 balance_interval = 63 215 balance_interval = 32 2 balance_interval = 31 2 balance_interval = 16 4 balance_interval = 8 1870 balance_interval = 4 65 balance_interval = 2 MASK=1 27 balance_interval = 175 37 balance_interval = 127 840 balance_interval = 64 167 balance_interval = 63 449 balance_interval = 32 84 balance_interval = 31 304 balance_interval = 16 1156 balance_interval = 8 2781 balance_interval = 4 428 balance_interval = 2 MASK=f 1 balance_interval = 175 1328 balance_interval = 128 44 balance_interval = 64 101 balance_interval = 63 25 balance_interval = 32 5 balance_interval = 31 23 balance_interval = 16 23 balance_interval = 8 4306 balance_interval = 4 177 balance_interval = 2 AFTER ----- Note how the high values almost disappear for all MASK values. The system has background tasks that could trigger the problem without simulate it even with MASK=0. MASK=0 103 balance_interval = 63 19 balance_interval = 31 194 balance_interval = 8 4827 balance_interval = 4 179 balance_interval = 2 MASK=1 131 balance_interval = 63 1 balance_interval = 31 87 balance_interval = 8 3600 balance_interval = 4 7 balance_interval = 2 MASK=f 8 balance_interval = 127 182 balance_interval = 63 3 balance_interval = 31 9 balance_interval = 16 415 balance_interval = 8 3415 balance_interval = 4 21 balance_interval = 2 Signed-off-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240324004552.999936-3-qyousef@layalina.io
-
Qais Yousef authored
So that we can use it to iterate through available capacities in the system. Sort asym_cap_list in descending order as expected users are likely to be interested on the highest capacity first. Make the list RCU protected to allow for cheap access in hot paths. Signed-off-by: Qais Yousef <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20240324004552.999936-2-qyousef@layalina.io
-
Ingo Molnar authored
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-
- 24 Mar, 2024 13 commits
-
-
Linus Torvalds authored
-
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efiLinus Torvalds authored
Pull EFI fixes from Ard Biesheuvel: - Fix logic that is supposed to prevent placement of the kernel image below LOAD_PHYSICAL_ADDR - Use the firmware stack in the EFI stub when running in mixed mode - Clear BSS only once when using mixed mode - Check efi.get_variable() function pointer for NULL before trying to call it * tag 'efi-fixes-for-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: fix panic in kdump kernel x86/efistub: Don't clear BSS twice in mixed mode x86/efistub: Call mixed mode boot services on the firmware's stack efi/libstub: fix efi_random_alloc() to allocate memory at alloc_min or higher address
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Thomas Gleixner: - Ensure that the encryption mask at boot is properly propagated on 5-level page tables, otherwise the PGD entry is incorrectly set to non-encrypted, which causes system crashes during boot. - Undo the deferred 5-level page table setup as it cannot work with memory encryption enabled. - Prevent inconsistent XFD state on CPU hotplug, where the MSR is reset to the default value but the cached variable is not, so subsequent comparisons might yield the wrong result and as a consequence the result prevents updating the MSR. - Register the local APIC address only once in the MPPARSE enumeration to prevent triggering the related WARN_ONs() in the APIC and topology code. - Handle the case where no APIC is found gracefully by registering a fake APIC in the topology code. That makes all related topology functions work correctly and does not affect the actual APIC driver code at all. - Don't evaluate logical IDs during early boot as the local APIC IDs are not yet enumerated and the invoked function returns an error code. Nothing requires the logical IDs before the final CPUID enumeration takes place, which happens after the enumeration. - Cure the fallout of the per CPU rework on UP which misplaced the copying of boot_cpu_data to per CPU data so that the final update to boot_cpu_data got lost which caused inconsistent state and boot crashes. - Use copy_from_kernel_nofault() in the kprobes setup as there is no guarantee that the address can be safely accessed. - Reorder struct members in struct saved_context to work around another kmemleak false positive - Remove the buggy code which tries to update the E820 kexec table for setup_data as that is never passed to the kexec kernel. - Update the resource control documentation to use the proper units. - Fix a Kconfig warning observed with tinyconfig * tag 'x86-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot/64: Move 5-level paging global variable assignments back x86/boot/64: Apply encryption mask to 5-level pagetable update x86/cpu: Add model number for another Intel Arrow Lake mobile processor x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD Documentation/x86: Document that resctrl bandwidth control units are MiB x86/mpparse: Register APIC address only once x86/topology: Handle the !APIC case gracefully x86/topology: Don't evaluate logical IDs during early boot x86/cpu: Ensure that CPU info updates are propagated on UP kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address x86/pm: Work around false positive kmemleak report in msr_build_context() x86/kexec: Do not update E820 kexec table for setup_data x86/config: Fix warning for 'make ARCH=x86_64 tinyconfig'
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler doc clarification from Thomas Gleixner: "A single update for the documentation of the base_slice_ns tunable to clarify that any value which is less than the tick slice has no effect because the scheduler tick is not guaranteed to happen within the set time slice" * tag 'sched-urgent-2024-03-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/doc: Update documentation for base_slice_ns and CONFIG_HZ relation
-
git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping fixes from Christoph Hellwig: "This has a set of swiotlb alignment fixes for sometimes very long standing bugs from Will. We've been discussion them for a while and they should be solid now" * tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE iommu/dma: Force swiotlb_max_mapping_size on an untrusted device swiotlb: Fix alignment checks when both allocation and DMA masks are present swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc() swiotlb: Enforce page alignment in swiotlb_alloc() swiotlb: Fix double-allocation of slots due to broken alignment handling
-
Oleksandr Tymoshenko authored
Check if get_next_variable() is actually valid pointer before calling it. In kdump kernel this method is set to NULL that causes panic during the kexec-ed kernel boot. Tested with QEMU and OVMF firmware. Fixes: bad267f9 ("efi: verify that variable services are supported") Signed-off-by: Oleksandr Tymoshenko <ovt@google.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-
Ard Biesheuvel authored
Clearing BSS should only be done once, at the very beginning. efi_pe_entry() is the entrypoint from the firmware, which may not clear BSS and so it is done explicitly. However, efi_pe_entry() is also used as an entrypoint by the mixed mode startup code, in which case BSS will already have been cleared, and doing it again at this point will corrupt global variables holding the firmware's GDT/IDT and segment selectors. So make the memset() conditional on whether the EFI stub is running in native mode. Fixes: b3810c5a ("x86/efistub: Clear decompressor BSS in native EFI entrypoint") Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-
Ard Biesheuvel authored
Normally, the EFI stub calls into the EFI boot services using the stack that was live when the stub was entered. According to the UEFI spec, this stack needs to be at least 128k in size - this might seem large but all asynchronous processing and event handling in EFI runs from the same stack and so quite a lot of space may be used in practice. In mixed mode, the situation is a bit different: the bootloader calls the 32-bit EFI stub entry point, which calls the decompressor's 32-bit entry point, where the boot stack is set up, using a fixed allocation of 16k. This stack is still in use when the EFI stub is started in 64-bit mode, and so all calls back into the EFI firmware will be using the decompressor's limited boot stack. Due to the placement of the boot stack right after the boot heap, any stack overruns have gone unnoticed. However, commit 5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code") moved the definition of the boot heap into C code, and now the boot stack is placed right at the base of BSS, where any overruns will corrupt the end of the .data section. While it would be possible to work around this by increasing the size of the boot stack, doing so would affect all x86 systems, and mixed mode systems are a tiny (and shrinking) fraction of the x86 installed base. So instead, record the firmware stack pointer value when entering from the 32-bit firmware, and switch to this stack every time a EFI boot service call is made. Cc: <stable@kernel.org> # v6.1+ Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
-
Tom Lendacky authored
Commit 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables") moved assignment of 5-level global variables to later in the boot in order to avoid having to use RIP relative addressing in order to set them. However, when running with 5-level paging and SME active (mem_encrypt=on), the variables are needed as part of the page table setup needed to encrypt the kernel (using pgd_none(), p4d_offset(), etc.). Since the variables haven't been set, the page table manipulation is done as if 4-level paging is active, causing the system to crash on boot. While only a subset of the assignments that were moved need to be set early, move all of the assignments back into check_la57_support() so that these assignments aren't spread between two locations. Instead of just reverting the fix, this uses the new RIP_REL_REF() macro when assigning the variables. Fixes: 63bed966 ("x86/startup_64: Defer assignment of 5-level paging global variables") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/2ca419f4d0de719926fd82353f6751f717590a86.1711122067.git.thomas.lendacky@amd.com
-
Tom Lendacky authored
When running with 5-level page tables, the kernel mapping PGD entry is updated to point to the P4D table. The assignment uses _PAGE_TABLE_NOENC, which, when SME is active (mem_encrypt=on), results in a page table entry without the encryption mask set, causing the system to crash on boot. Change the assignment to use _PAGE_TABLE instead of _PAGE_TABLE_NOENC so that the encryption mask is set for the PGD entry. Fixes: 533568e0 ("x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/8f20345cda7dbba2cf748b286e1bc00816fe649a.1711122067.git.thomas.lendacky@amd.com
-
Tony Luck authored
This one is the regular laptop CPU. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240322161725.195614-1-tony.luck@intel.com
-
Adamos Ttofari authored
Commit 67236547 ("x86/fpu: Update XFD state where required") and commit 8bf26758 ("x86/fpu: Add XFD state to fpstate") introduced a per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in order to avoid unnecessary writes to the MSR. On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which wipes out any stale state. But the per CPU cached xfd value is not reset, which brings them out of sync. As a consequence a subsequent xfd_update_state() might fail to update the MSR which in turn can result in XRSTOR raising a #NM in kernel space, which crashes the kernel. To fix this, introduce xfd_set_state() to write xfd_state together with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD. Fixes: 67236547 ("x86/fpu: Update XFD state where required") Signed-off-by: Adamos Ttofari <attofari@amazon.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240322230439.456571-1-chang.seok.bae@intel.com Closes: https://lore.kernel.org/lkml/20230511152818.13839-1-attofari@amazon.de
-
Tony Luck authored
The memory bandwidth software controller uses 2^20 units rather than 10^6. See mbm_bw_count() which computes bandwidth using the "SZ_1M" Linux define for 0x00100000. Update the documentation to use MiB when describing this feature. It's too late to fix the mount option "mba_MBps" as that is now an established user interface. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240322182016.196544-1-tony.luck@intel.com
-
- 23 Mar, 2024 5 commits
-
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fixes from Thomas Gleixner: "Two regression fixes for the timer and timer migration code: - Prevent endless timer requeuing which is caused by two CPUs racing out of idle. This happens when the last CPU goes idle and therefore has to ensure to expire the pending global timers and some other CPU come out of idle at the same time and the other CPU wins the race and expires the global queue. This causes the last CPU to chase ghost timers forever and reprogramming it's clockevent device endlessly. Cure this by re-evaluating the wakeup time unconditionally. - The split into local (pinned) and global timers in the timer wheel caused a regression for NOHZ full as it broke the idle tracking of global timers. On NOHZ full this prevents an self IPI being sent which in turn causes the timer to be not programmed and not being expired on time. Restore the idle tracking for the global timer base so that the self IPI condition for NOHZ full is working correctly again" * tag 'timers-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Fix removed self-IPI on global timer's enqueue in nohz_full timers/migration: Fix endless timer requeue after idle interrupts
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull more clocksource updates from Thomas Gleixner: "A set of updates for clocksource and clockevent drivers: - A fix for the prescaler of the ARM global timer where the prescaler mask define only covered 4 bits while it is actully 8 bits wide. This obviously restricted the possible range of prescaler adjustments - A fix for the RISC-V timer which prevents a timer interrupt being raised while the timer is initialized - A set of device tree updates to support new system on chips in various drivers - Kernel-doc and other cleanups all over the place" * tag 'timers-core-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource/drivers/timer-riscv: Clear timer interrupt on timer initialization dt-bindings: timer: Add support for cadence TTC PWM clocksource/drivers/arm_global_timer: Simplify prescaler register access clocksource/drivers/arm_global_timer: Guard against division by zero clocksource/drivers/arm_global_timer: Make gt_target_rate unsigned long dt-bindings: timer: add Ralink SoCs system tick counter clocksource: arm_global_timer: fix non-kernel-doc comment clocksource/drivers/arm_global_timer: Remove stray tab clocksource/drivers/arm_global_timer: Fix maximum prescaler value clocksource/drivers/imx-sysctr: Add i.MX95 support clocksource/drivers/imx-sysctr: Drop use global variables dt-bindings: timer: nxp,sysctr-timer: support i.MX95 dt-bindings: timer: renesas: ostm: Document RZ/Five SoC dt-bindings: timer: renesas,tmu: Document input capture interrupt clocksource/drivers/ti-32K: Fix misuse of "/**" comment clocksource/drivers/stm32: Fix all kernel-doc warnings dt-bindings: timer: exynos4210-mct: Add google,gs101-mct compatible clocksource/drivers/imx: Fix -Wunused-but-set-variable warning
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull irq fixes from Thomas Gleixner: "A series of fixes for the Renesas RZG21 interrupt chip driver to prevent spurious and misrouted interrupts. - Ensure that posted writes are flushed in the eoi() callback - Ensure that interrupts are masked at the chip level when the trigger type is changed - Clear the interrupt status register when setting up edge type trigger modes - Ensure that the trigger type and routing information is set before the interrupt is enabled" * tag 'irq-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/renesas-rzg2l: Do not set TIEN and TINT source at the same time irqchip/renesas-rzg2l: Prevent spurious interrupts when setting trigger type irqchip/renesas-rzg2l: Rename rzg2l_irq_eoi() irqchip/renesas-rzg2l: Rename rzg2l_tint_eoi() irqchip/renesas-rzg2l: Flush posted write in irq_eoi()
-
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull core entry fix from Thomas Gleixner: "A single fix for the generic entry code: The trace_sys_enter() tracepoint can modify the syscall number via kprobes or BPF in pt_regs, but that requires that the syscall number is re-evaluted from pt_regs after the tracepoint. A seccomp fix in that area removed the re-evaluation so the change does not take effect as the code just uses the locally cached number. Restore the original behaviour by re-evaluating the syscall number after the tracepoint" * tag 'core-entry-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: entry: Respect changes to system call number by trace_sys_enter()
-
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull more powerpc updates from Michael Ellerman: - Handle errors in mark_rodata_ro() and mark_initmem_nx() - Make struct crash_mem available without CONFIG_CRASH_DUMP Thanks to Christophe Leroy and Hari Bathini. * tag 'powerpc-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/kdump: Split KEXEC_CORE and CRASH_DUMP dependency powerpc/kexec: split CONFIG_KEXEC_FILE and CONFIG_CRASH_DUMP kexec/kdump: make struct crash_mem available without CONFIG_CRASH_DUMP powerpc: Handle error in mark_rodata_ro() and mark_initmem_nx()
-