From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E2674A3C for ; Sat, 24 Feb 2024 01:49:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708739374; cv=none; b=uBBkfl7bVWAv3bOHGEksICwSRUGPTuNG7xeFn3e2RPKnw7w5cyPsEbe/83I7WWJCuGJvbgfbppZsFGnCxdGUKk5bePs+yHsQsrBXCQbx4vk9QDwvG05d9wir+JgN/Egi+Gyk7QrTUQQ+qGnQKWZWxPc7b0wXUeKxeu10siva6RM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708739374; c=relaxed/simple; bh=mZewUPduSwP2Q7NdnL9gyS9PNqsCoumHLFbVt66/rE0=; h=Date:To:From:Subject:Message-Id; b=qmAuk2xpC+rtlfQWe9Zkso0hrIVbncG6ELYQAIoxaAR86bNL/PwRdekyvRXbLeIfPKev95ARHpNTyMaTZtq+srbKPj6fWwSGEETxHIIb4qAEtXmVT4b00IpS6FjleGiWeG6hPmr1FFSoNV6X4gADEdycksmYy7DlRelZt8csjIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=At+L0duM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="At+L0duM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 213BFC433C7; Sat, 24 Feb 2024 01:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1708739374; bh=mZewUPduSwP2Q7NdnL9gyS9PNqsCoumHLFbVt66/rE0=; h=Date:To:From:Subject:From; b=At+L0duMSDFhF5fe8I8uKV4PiTz3KS0dva5BSSoxSwadf8HMN647BudMjCTBg4n86 Se50uZtqoGLBv9fvEIL87xMFplZ927sBDjgAb5nGgLfaV9wtb48M3MAVw8uJk0j00N GluBerNZTDm67h7qafXj7Pd4Uug7XGF57tpWh9UA= Date: Fri, 23 Feb 2024 17:49:33 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,paulmck@kernel.org,oleksiy.avramchenko@sony.com,lstoakes@gmail.com,Liam.Howlett@oracle.com,k-hagio-ab@nec.com,joel@joelfernandes.org,hch@lst.de,david@fromorbit.com,bhe@redhat.com,urezki@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-vmalloc-remove-global-purge_vmap_area_root-rb-tree.patch removed from -mm tree Message-Id: <20240224014934.213BFC433C7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: vmalloc: remove global purge_vmap_area_root rb-tree has been removed from the -mm tree. Its filename was mm-vmalloc-remove-global-purge_vmap_area_root-rb-tree.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: "Uladzislau Rezki (Sony)" Subject: mm: vmalloc: remove global purge_vmap_area_root rb-tree Date: Tue, 2 Jan 2024 19:46:28 +0100 Similar to busy VA, lazily-freed area is stored to a node it belongs to. Such approach does not require any global locking primitive, instead an access becomes scalable what mitigates a contention. This patch removes a global purge-lock, global purge-tree and global purge list. Link: https://lkml.kernel.org/r/20240102184633.748113-7-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Baoquan He Cc: Christoph Hellwig Cc: Dave Chinner Cc: Joel Fernandes (Google) Cc: Kazuhito Hagio Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Oleksiy Avramchenko Cc: Paul E. McKenney Signed-off-by: Andrew Morton --- mm/vmalloc.c | 135 +++++++++++++++++++++++++++++-------------------- 1 file changed, 82 insertions(+), 53 deletions(-) --- a/mm/vmalloc.c~mm-vmalloc-remove-global-purge_vmap_area_root-rb-tree +++ a/mm/vmalloc.c @@ -731,10 +731,6 @@ EXPORT_SYMBOL(vmalloc_to_pfn); static DEFINE_SPINLOCK(free_vmap_area_lock); static bool vmap_initialized __read_mostly; -static struct rb_root purge_vmap_area_root = RB_ROOT; -static LIST_HEAD(purge_vmap_area_list); -static DEFINE_SPINLOCK(purge_vmap_area_lock); - /* * This kmem_cache is used for vmap_area objects. Instead of * allocating from slab we reuse an object from this cache to @@ -782,6 +778,12 @@ struct rb_list { static struct vmap_node { /* Bookkeeping data of this node. */ struct rb_list busy; + struct rb_list lazy; + + /* + * Ready-to-free areas. + */ + struct list_head purge_list; } single; static struct vmap_node *vmap_nodes = &single; @@ -1766,40 +1768,22 @@ static DEFINE_MUTEX(vmap_purge_lock); /* for per-CPU blocks */ static void purge_fragmented_blocks_allcpus(void); +static cpumask_t purge_nodes; /* * Purges all lazily-freed vmap areas. */ -static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) +static unsigned long +purge_vmap_node(struct vmap_node *vn) { - unsigned long resched_threshold; - unsigned int num_purged_areas = 0; - struct list_head local_purge_list; + unsigned long num_purged_areas = 0; struct vmap_area *va, *n_va; - lockdep_assert_held(&vmap_purge_lock); - - spin_lock(&purge_vmap_area_lock); - purge_vmap_area_root = RB_ROOT; - list_replace_init(&purge_vmap_area_list, &local_purge_list); - spin_unlock(&purge_vmap_area_lock); - - if (unlikely(list_empty(&local_purge_list))) - goto out; - - start = min(start, - list_first_entry(&local_purge_list, - struct vmap_area, list)->va_start); - - end = max(end, - list_last_entry(&local_purge_list, - struct vmap_area, list)->va_end); - - flush_tlb_kernel_range(start, end); - resched_threshold = lazy_max_pages() << 1; + if (list_empty(&vn->purge_list)) + return 0; spin_lock(&free_vmap_area_lock); - list_for_each_entry_safe(va, n_va, &local_purge_list, list) { + list_for_each_entry_safe(va, n_va, &vn->purge_list, list) { unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; unsigned long orig_start = va->va_start; unsigned long orig_end = va->va_end; @@ -1821,13 +1805,55 @@ static bool __purge_vmap_area_lazy(unsig atomic_long_sub(nr, &vmap_lazy_nr); num_purged_areas++; - - if (atomic_long_read(&vmap_lazy_nr) < resched_threshold) - cond_resched_lock(&free_vmap_area_lock); } spin_unlock(&free_vmap_area_lock); -out: + return num_purged_areas; +} + +/* + * Purges all lazily-freed vmap areas. + */ +static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) +{ + unsigned long num_purged_areas = 0; + struct vmap_node *vn; + int i; + + lockdep_assert_held(&vmap_purge_lock); + purge_nodes = CPU_MASK_NONE; + + for (i = 0; i < nr_vmap_nodes; i++) { + vn = &vmap_nodes[i]; + + INIT_LIST_HEAD(&vn->purge_list); + + if (RB_EMPTY_ROOT(&vn->lazy.root)) + continue; + + spin_lock(&vn->lazy.lock); + WRITE_ONCE(vn->lazy.root.rb_node, NULL); + list_replace_init(&vn->lazy.head, &vn->purge_list); + spin_unlock(&vn->lazy.lock); + + start = min(start, list_first_entry(&vn->purge_list, + struct vmap_area, list)->va_start); + + end = max(end, list_last_entry(&vn->purge_list, + struct vmap_area, list)->va_end); + + cpumask_set_cpu(i, &purge_nodes); + } + + if (cpumask_weight(&purge_nodes) > 0) { + flush_tlb_kernel_range(start, end); + + for_each_cpu(i, &purge_nodes) { + vn = &nodes[i]; + num_purged_areas += purge_vmap_node(vn); + } + } + trace_purge_vmap_area_lazy(start, end, num_purged_areas); return num_purged_areas > 0; } @@ -1846,16 +1872,9 @@ static void reclaim_and_purge_vmap_areas static void drain_vmap_area_work(struct work_struct *work) { - unsigned long nr_lazy; - - do { - mutex_lock(&vmap_purge_lock); - __purge_vmap_area_lazy(ULONG_MAX, 0); - mutex_unlock(&vmap_purge_lock); - - /* Recheck if further work is required. */ - nr_lazy = atomic_long_read(&vmap_lazy_nr); - } while (nr_lazy > lazy_max_pages()); + mutex_lock(&vmap_purge_lock); + __purge_vmap_area_lazy(ULONG_MAX, 0); + mutex_unlock(&vmap_purge_lock); } /* @@ -1865,6 +1884,7 @@ static void drain_vmap_area_work(struct */ static void free_vmap_area_noflush(struct vmap_area *va) { + struct vmap_node *vn = addr_to_node(va->va_start); unsigned long nr_lazy_max = lazy_max_pages(); unsigned long va_start = va->va_start; unsigned long nr_lazy; @@ -1878,10 +1898,9 @@ static void free_vmap_area_noflush(struc /* * Merge or place it to the purge tree/list. */ - spin_lock(&purge_vmap_area_lock); - merge_or_add_vmap_area(va, - &purge_vmap_area_root, &purge_vmap_area_list); - spin_unlock(&purge_vmap_area_lock); + spin_lock(&vn->lazy.lock); + merge_or_add_vmap_area(va, &vn->lazy.root, &vn->lazy.head); + spin_unlock(&vn->lazy.lock); trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max); @@ -4411,15 +4430,21 @@ static void show_numa_info(struct seq_fi static void show_purge_info(struct seq_file *m) { + struct vmap_node *vn; struct vmap_area *va; + int i; - spin_lock(&purge_vmap_area_lock); - list_for_each_entry(va, &purge_vmap_area_list, list) { - seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", - (void *)va->va_start, (void *)va->va_end, - va->va_end - va->va_start); + for (i = 0; i < nr_vmap_nodes; i++) { + vn = &vmap_nodes[i]; + + spin_lock(&vn->lazy.lock); + list_for_each_entry(va, &vn->lazy.head, list) { + seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start); + } + spin_unlock(&vn->lazy.lock); } - spin_unlock(&purge_vmap_area_lock); } static int s_show(struct seq_file *m, void *p) @@ -4558,6 +4583,10 @@ static void vmap_init_nodes(void) vn->busy.root = RB_ROOT; INIT_LIST_HEAD(&vn->busy.head); spin_lock_init(&vn->busy.lock); + + vn->lazy.root = RB_ROOT; + INIT_LIST_HEAD(&vn->lazy.head); + spin_lock_init(&vn->lazy.lock); } } _ Patches currently in -mm which might be from urezki@gmail.com are