search for: switch_mm

vhost net module wants to do copy to/from user from a kernel thread, which needs switch_mm (like what fs/aio has). export cpu_tlbstate to make this possible Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/x86/mm/tlb.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 821e970..e33a5f0 100644 --- a/ar...

vhost net module wants to do copy to/from user from a kernel thread, which needs switch_mm (like what fs/aio has). export cpu_tlbstate to make this possible Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/x86/mm/tlb.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 821e970..e33a5f0 100644 --- a/ar...

...543a9e1cc..c51a84132d7c 100644 --- a/include/linux/mmu_context.h +++ b/include/linux/mmu_context.h @@ -4,11 +4,6 @@ #include <asm/mmu_context.h> -struct mm_struct; - -void use_mm(struct mm_struct *mm); -void unuse_mm(struct mm_struct *mm); - /* Architectures that care about IRQ state in switch_mm can override this. */ #ifndef switch_mm_irqs_off # define switch_mm_irqs_off switch_mm diff --git a/kernel/kthread.c b/kernel/kthread.c index bfbfa481be3a..ce4610316377 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1,13 +1,17 @@ // SPDX-License-Identifier: GPL-2.0-only /* Kernel thre...

I was also able to get the LDT switching functionality out of the critical path in switch_mm, which reduces the number of function calls, potential TLB misses and code size. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/include/asm-i386/desc.h =================================================================== --- linux-2.6.14-zach-work.orig/include/a...

I was also able to get the LDT switching functionality out of the critical path in switch_mm, which reduces the number of function calls, potential TLB misses and code size. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/include/asm-i386/desc.h =================================================================== --- linux-2.6.14-zach-work.orig/include/a...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...called only - * from a kernel thread context) - */ -static void use_mm(struct mm_struct *mm) -{ - struct mm_struct *active_mm; - struct task_struct *tsk = current; - - task_lock(tsk); - active_mm = tsk->active_mm; - atomic_inc(&mm->mm_count); - tsk->mm = mm; - tsk->active_mm = mm; - switch_mm(active_mm, mm, tsk); - task_unlock(tsk); - - mmdrop(active_mm); -} - -/* - * unuse_mm - * Reverses the effect of use_mm, i.e. releases the - * specified mm context which was earlier taken on - * by the calling kernel thread - * (Note: this routine is intended to be called only - * from a kernel thr...

...vel4_pgt)); } __flush_tlb_all(); } Index: clean-start/include/asm-x86_64/mmu_context.h =================================================================== --- clean-start.orig/include/asm-x86_64/mmu_context.h +++ clean-start/include/asm-x86_64/mmu_context.h @@ -42,7 +42,7 @@ static inline void switch_mm(struct mm_s load_cr3(next->pgd); if (unlikely(next->context.ldt != prev->context.ldt)) - load_LDT_nolock(&next->context, cpu); + load_LDT_nolock(&next->context); } #ifdef CONFIG_SMP else { @@ -55,7 +55,7 @@ static inline void switch_mm(struct mm_s * to...

...vel4_pgt)); } __flush_tlb_all(); } Index: clean-start/include/asm-x86_64/mmu_context.h =================================================================== --- clean-start.orig/include/asm-x86_64/mmu_context.h +++ clean-start/include/asm-x86_64/mmu_context.h @@ -42,7 +42,7 @@ static inline void switch_mm(struct mm_s load_cr3(next->pgd); if (unlikely(next->context.ldt != prev->context.ldt)) - load_LDT_nolock(&next->context, cpu); + load_LDT_nolock(&next->context); } #ifdef CONFIG_SMP else { @@ -55,7 +55,7 @@ static inline void switch_mm(struct mm_s * to...

In debugging the sles9 port on 64 bit MP machines, I am seeing a problem where the hypervisor takes a fault in loading fs in the context switch code (load_segments()). The selector is one of the TLS selectors. It appears that the cpu in question has updated this selector with a value of 0 just prior to the problem I am seeing. Looking at the Linux context switch code, we first update the TLS

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API.

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API.