| Message ID | 20240222190911.1903054-1-yosryahmed@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [mm-stable,1/2] x86/mm: further clarify switch_mm_irqs_off() documentation | expand |
On 2/22/24 11:09, Yosry Ahmed wrote: > Commit accf6b23d1e5a ("x86/mm: clarify "prev" usage in > switch_mm_irqs_off()") attempted to clarify x86's usage of the arguments > passed by generic code, specifically the "prev" argument the is unused > by x86. However, it could have done a better job with the comment above > switch_mm_irqs_off(). Rewrite this comment according to Dave Hansen's > suggestion. Looks good, thanks for sending this! Acked-by: Dave Hansen <dave.hansen@intel.com>
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index bf9605caf24f7..b67545baf6973 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -493,10 +493,10 @@ static inline void cr4_update_pce_mm(struct mm_struct *mm) { } #endif /* - * The "prev" argument passed by the caller does not always match CR3. For - * example, the scheduler passes in active_mm when switching from lazy TLB mode - * to normal mode, but switch_mm_irqs_off() can be called from x86 code without - * updating active_mm. Use cpu_tlbstate.loaded_mm instead. + * This optimizes when not actually switching mm's. Some architectures use the + * 'unused' argument for this optimization, but x86 must use + * 'cpu_tlbstate.loaded_mm' instead because it does not always keep + * 'current->active_mm' up to date. */ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next, struct task_struct *tsk)
Commit accf6b23d1e5a ("x86/mm: clarify "prev" usage in switch_mm_irqs_off()") attempted to clarify x86's usage of the arguments passed by generic code, specifically the "prev" argument the is unused by x86. However, it could have done a better job with the comment above switch_mm_irqs_off(). Rewrite this comment according to Dave Hansen's suggestion. Fixes: accf6b23d1e5 ("x86/mm: clarify "prev" usage in switch_mm_irqs_off()") Suggested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Yosry Ahmed <yosryahmed@google.com> --- arch/x86/mm/tlb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)