From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3066C77B6E for ; Tue, 28 Mar 2023 23:21:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229756AbjC1XVL (ORCPT ); Tue, 28 Mar 2023 19:21:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229880AbjC1XVJ (ORCPT ); Tue, 28 Mar 2023 19:21:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B72DD1BFD for ; Tue, 28 Mar 2023 16:21:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3F3DF619F4 for ; Tue, 28 Mar 2023 23:21:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92971C433EF; Tue, 28 Mar 2023 23:21:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1680045666; bh=ro0X2vV3oebRRa2KhQT9BASN6f5JGUCCaLchduO32r4=; h=Date:To:From:Subject:From; b=fm55L6Ph8zU5dG2sZFAHI0tpJqpUklsEMwAnyxCDKaEx/rZakKkDHntVID9mrh0BB xSbVZooJz4zeVuD4tqCdXCPuZbnQBkenmlRLGP4gN2WkR7CKDeXkeQzRtUTYDVKLwU CHyqtGeOAKBJy0DoR+/J5+Sieq2ktQIn6xx5HFDw= Date: Tue, 28 Mar 2023 16:21:06 -0700 To: mm-commits@vger.kernel.org, will@kernel.org, torvalds@linux-foundation.org, riel@redhat.com, peterz@infradead.org, nadav.amit@gmail.com, mpe@ellerman.id.au, luto@kernel.org, dave.hansen@linux.intel.com, christophe.leroy@csgroup.eu, catalin.marinas@arm.com, npiggin@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions.patch removed from -mm tree Message-Id: <20230328232106.92971C433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: lazy tlb: introduce lazy tlb mm refcount helper functions has been removed from the -mm tree. Its filename was lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Nicholas Piggin Subject: lazy tlb: introduce lazy tlb mm refcount helper functions Date: Fri, 3 Feb 2023 17:18:34 +1000 Add explicit _lazy_tlb annotated functions for lazy tlb mm refcounting. This makes the lazy tlb mm references more obvious, and allows the refcounting scheme to be modified in later changes. There is no functional change with this patch. Link: https://lkml.kernel.org/r/20230203071837.1136453-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin Acked-by: Linus Torvalds Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Christophe Leroy Cc: Dave Hansen Cc: Michael Ellerman Cc: Nadav Amit Cc: Peter Zijlstra Cc: Rik van Riel Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm/mach-rpc/ecard.c | 2 +- arch/powerpc/kernel/smp.c | 2 +- arch/powerpc/mm/book3s64/radix_tlb.c | 4 ++-- fs/exec.c | 2 +- include/linux/sched/mm.h | 16 ++++++++++++++++ kernel/cpu.c | 2 +- kernel/exit.c | 2 +- kernel/kthread.c | 12 ++++++++++-- kernel/sched/core.c | 15 ++++++++------- 9 files changed, 41 insertions(+), 16 deletions(-) --- a/arch/arm/mach-rpc/ecard.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/arch/arm/mach-rpc/ecard.c @@ -253,7 +253,7 @@ static int ecard_init_mm(void) current->mm = mm; current->active_mm = mm; activate_mm(active_mm, mm); - mmdrop(active_mm); + mmdrop_lazy_tlb(active_mm); ecard_init_pgtables(mm); return 0; } --- a/arch/powerpc/kernel/smp.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/arch/powerpc/kernel/smp.c @@ -1611,7 +1611,7 @@ void start_secondary(void *unused) if (IS_ENABLED(CONFIG_PPC32)) setup_kup(); - mmgrab(&init_mm); + mmgrab_lazy_tlb(&init_mm); current->active_mm = &init_mm; smp_store_cpu_info(cpu); --- a/arch/powerpc/mm/book3s64/radix_tlb.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/arch/powerpc/mm/book3s64/radix_tlb.c @@ -797,10 +797,10 @@ void exit_lazy_flush_tlb(struct mm_struc if (current->active_mm == mm) { WARN_ON_ONCE(current->mm != NULL); /* Is a kernel thread and is using mm as the lazy tlb */ - mmgrab(&init_mm); + mmgrab_lazy_tlb(&init_mm); current->active_mm = &init_mm; switch_mm_irqs_off(mm, &init_mm, current); - mmdrop(mm); + mmdrop_lazy_tlb(mm); } /* --- a/fs/exec.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/fs/exec.c @@ -1034,7 +1034,7 @@ static int exec_mmap(struct mm_struct *m mmput(old_mm); return 0; } - mmdrop(active_mm); + mmdrop_lazy_tlb(active_mm); return 0; } --- a/include/linux/sched/mm.h~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/include/linux/sched/mm.h @@ -79,6 +79,22 @@ static inline void mmdrop_sched(struct m } #endif +/* Helpers for lazy TLB mm refcounting */ +static inline void mmgrab_lazy_tlb(struct mm_struct *mm) +{ + mmgrab(mm); +} + +static inline void mmdrop_lazy_tlb(struct mm_struct *mm) +{ + mmdrop(mm); +} + +static inline void mmdrop_lazy_tlb_sched(struct mm_struct *mm) +{ + mmdrop_sched(mm); +} + /** * mmget() - Pin the address space associated with a &struct mm_struct. * @mm: The address space to pin. --- a/kernel/cpu.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/kernel/cpu.c @@ -623,7 +623,7 @@ static int finish_cpu(unsigned int cpu) */ if (mm != &init_mm) idle->active_mm = &init_mm; - mmdrop(mm); + mmdrop_lazy_tlb(mm); return 0; } --- a/kernel/exit.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/kernel/exit.c @@ -537,7 +537,7 @@ static void exit_mm(void) return; sync_mm_rss(mm); mmap_read_lock(mm); - mmgrab(mm); + mmgrab_lazy_tlb(mm); BUG_ON(mm != current->active_mm); /* more a memory barrier than a real lock */ task_lock(current); --- a/kernel/kthread.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/kernel/kthread.c @@ -1415,6 +1415,11 @@ void kthread_use_mm(struct mm_struct *mm WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); WARN_ON_ONCE(tsk->mm); + /* + * It is possible for mm to be the same as tsk->active_mm, but + * we must still mmgrab(mm) and mmdrop_lazy_tlb(active_mm), + * because these references are not equivalent. + */ mmgrab(mm); task_lock(tsk); @@ -1438,9 +1443,9 @@ void kthread_use_mm(struct mm_struct *mm * memory barrier after storing to tsk->mm, before accessing * user-space memory. A full memory barrier for membarrier * {PRIVATE,GLOBAL}_EXPEDITED is implicitly provided by - * mmdrop(). + * mmdrop_lazy_tlb(). */ - mmdrop(active_mm); + mmdrop_lazy_tlb(active_mm); } EXPORT_SYMBOL_GPL(kthread_use_mm); @@ -1468,10 +1473,13 @@ void kthread_unuse_mm(struct mm_struct * local_irq_disable(); tsk->mm = NULL; membarrier_update_current_mm(NULL); + mmgrab_lazy_tlb(mm); /* active_mm is still 'mm' */ enter_lazy_tlb(mm, tsk); local_irq_enable(); task_unlock(tsk); + + mmdrop(mm); } EXPORT_SYMBOL_GPL(kthread_unuse_mm); --- a/kernel/sched/core.c~lazy-tlb-introduce-lazy-tlb-mm-refcount-helper-functions +++ a/kernel/sched/core.c @@ -5203,13 +5203,14 @@ static struct rq *finish_task_switch(str * rq->curr, before returning to userspace, so provide them here: * * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly - * provided by mmdrop(), + * provided by mmdrop_lazy_tlb(), * - a sync_core for SYNC_CORE. */ if (mm) { membarrier_mm_sync_core_before_usermode(mm); - mmdrop_sched(mm); + mmdrop_lazy_tlb_sched(mm); } + if (unlikely(prev_state == TASK_DEAD)) { if (prev->sched_class->task_dead) prev->sched_class->task_dead(prev); @@ -5266,9 +5267,9 @@ context_switch(struct rq *rq, struct tas /* * kernel -> kernel lazy + transfer active - * user -> kernel lazy + mmgrab() active + * user -> kernel lazy + mmgrab_lazy_tlb() active * - * kernel -> user switch + mmdrop() active + * kernel -> user switch + mmdrop_lazy_tlb() active * user -> user switch */ if (!next->mm) { // to kernel @@ -5276,7 +5277,7 @@ context_switch(struct rq *rq, struct tas next->active_mm = prev->active_mm; if (prev->mm) // from user - mmgrab(prev->active_mm); + mmgrab_lazy_tlb(prev->active_mm); else prev->active_mm = NULL; } else { // to user @@ -5293,7 +5294,7 @@ context_switch(struct rq *rq, struct tas lru_gen_use_mm(next->mm); if (!prev->mm) { // from kernel - /* will mmdrop() in finish_task_switch(). */ + /* will mmdrop_lazy_tlb() in finish_task_switch(). */ rq->prev_mm = prev->active_mm; prev->active_mm = NULL; } @@ -9935,7 +9936,7 @@ void __init sched_init(void) /* * The boot idle thread does lazy MMU switching as well: */ - mmgrab(&init_mm); + mmgrab_lazy_tlb(&init_mm); enter_lazy_tlb(&init_mm, current); /* _ Patches currently in -mm which might be from npiggin@gmail.com are