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 42905C433F5 for ; Thu, 20 Jan 2022 11:59:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232418AbiATL7B (ORCPT ); Thu, 20 Jan 2022 06:59:01 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:34620 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232262AbiATL6u (ORCPT ); Thu, 20 Jan 2022 06:58:50 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 20F7C1F3A9; Thu, 20 Jan 2022 11:58:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1642679928; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G0bE+QNoeXrZ/9XBe6IJhaAGFRXVIa34iInEL3UPifI=; b=wWHVQhQfZHaR4A49v0RdYHWzgIymU/So/8WdcmuQv/BaZiUUP4qRmgcFFkqX5rtj9C/xg6 tpstC1fszBfkAeKClTTuxqgaTtQOu5PeI/Tkhqnj4lZgNWgkVNLobX7BYJLK6HZKRthL5d fEhJnKyn7Mg2TZUPqAUdE0DTthzLxRI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1642679928; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G0bE+QNoeXrZ/9XBe6IJhaAGFRXVIa34iInEL3UPifI=; b=scLZd7lihVsYbP2S+UchL/cWnLdV0qwCmRtrjJA/1OjSYYbz6ZsHzywfA2rCBob+4wZu/M ABvuhyKQMSnLApBA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id C754E13B51; Thu, 20 Jan 2022 11:58:47 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id yD3RL3dO6WGvUQAAMHmgww (envelope-from ); Thu, 20 Jan 2022 11:58:47 +0000 Message-ID: <10798a7d-e157-03c2-abf4-f005a3507cae@suse.cz> Date: Thu, 20 Jan 2022 12:58:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Liam Howlett , "maple-tree@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Andrew Morton Cc: Song Liu , Davidlohr Bueso , "Paul E . McKenney" , Matthew Wilcox , Laurent Dufour , David Rientjes , Axel Rasmussen , Suren Baghdasaryan , Rik van Riel , Peter Zijlstra , Michel Lespinasse , Jerome Glisse , Minchan Kim , Joel Fernandes , Rom Lemarchand References: <20211201142918.921493-1-Liam.Howlett@oracle.com> <20211201142918.921493-56-Liam.Howlett@oracle.com> From: Vlastimil Babka Subject: Re: [PATCH v4 55/66] mm/mempolicy: Use maple tree iterators instead of vma linked list In-Reply-To: <20211201142918.921493-56-Liam.Howlett@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/1/21 15:30, Liam Howlett wrote: > From: "Liam R. Howlett" > > Signed-off-by: Matthew Wilcox (Oracle) > Signed-off-by: Liam R. Howlett > --- > mm/mempolicy.c | 53 ++++++++++++++++++++++++++------------------------ > 1 file changed, 28 insertions(+), 25 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 10e9c87260ed..0e2d918f4f30 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -377,9 +377,10 @@ void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new) > void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new) > { > struct vm_area_struct *vma; > + MA_STATE(mas, &mm->mm_mt, 0, 0); VMA_ITERATOR? > > mmap_write_lock(mm); > - for (vma = mm->mmap; vma; vma = vma->vm_next) > + mas_for_each(&mas, vma, ULONG_MAX) > mpol_rebind_policy(vma->vm_policy, new); > mmap_write_unlock(mm); > } > @@ -652,7 +653,7 @@ static unsigned long change_prot_numa(struct vm_area_struct *vma, > static int queue_pages_test_walk(unsigned long start, unsigned long end, > struct mm_walk *walk) > { > - struct vm_area_struct *vma = walk->vma; > + struct vm_area_struct *next, *vma = walk->vma; > struct queue_pages *qp = walk->private; > unsigned long endvma = vma->vm_end; > unsigned long flags = qp->flags; > @@ -667,9 +668,10 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end, > /* hole at head side of range */ > return -EFAULT; > } > + next = find_vma(vma->vm_mm, vma->vm_end); > if (!(flags & MPOL_MF_DISCONTIG_OK) && > ((vma->vm_end < qp->end) && > - (!vma->vm_next || vma->vm_end < vma->vm_next->vm_start))) > + (!next || vma->vm_end < next->vm_start))) > /* hole at middle or tail of range */ > return -EFAULT; > > @@ -783,28 +785,24 @@ static int vma_replace_policy(struct vm_area_struct *vma, > static int mbind_range(struct mm_struct *mm, unsigned long start, > unsigned long end, struct mempolicy *new_pol) > { > - struct vm_area_struct *next; > + MA_STATE(mas, &mm->mm_mt, start - 1, start - 1); > struct vm_area_struct *prev; > struct vm_area_struct *vma; > int err = 0; > pgoff_t pgoff; > - unsigned long vmstart; > - unsigned long vmend; > - > - vma = find_vma(mm, start); > - VM_BUG_ON(!vma); > > - prev = vma->vm_prev; > - if (start > vma->vm_start) > - prev = vma; > + prev = mas_find_rev(&mas, 0); > + if (prev && (start < prev->vm_end)) > + vma = prev; > + else > + vma = mas_next(&mas, end - 1); > > - for (; vma && vma->vm_start < end; prev = vma, vma = next) { > - next = vma->vm_next; > - vmstart = max(start, vma->vm_start); > - vmend = min(end, vma->vm_end); > + do { > + unsigned long vmstart = max(start, vma->vm_start); > + unsigned long vmend = min(end, vma->vm_end); What if vma is null? Shouldn't this rather be a "for (; vma; vma = mas_next(...)" > > if (mpol_equal(vma_policy(vma), new_pol)) > - continue; > + goto next; > > pgoff = vma->vm_pgoff + > ((vmstart - vma->vm_start) >> PAGE_SHIFT); > @@ -812,8 +810,8 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, > vma->anon_vma, vma->vm_file, pgoff, > new_pol, vma->vm_userfaultfd_ctx); > if (prev) { > + mas_pause(&mas); > vma = prev; > - next = vma->vm_next; > if (mpol_equal(vma_policy(vma), new_pol)) > continue; > /* vma_merge() joined vma && vma->next, case 8 */ > @@ -823,19 +821,23 @@ static int mbind_range(struct mm_struct *mm, unsigned long start, > err = split_vma(vma->vm_mm, vma, vmstart, 1); > if (err) > goto out; > + mas_pause(&mas); > } > if (vma->vm_end != vmend) { > err = split_vma(vma->vm_mm, vma, vmend, 0); > if (err) > goto out; > + /* mas_pause() unnecessary as the loop is ending */ > } > - replace: > +replace: > err = vma_replace_policy(vma, new_pol); > if (err) > goto out; > - } > +next: > + prev = vma; > + } while ((vma = mas_next(&mas, end - 1)) != NULL); > > - out: > +out: > return err; > } > > @@ -1053,6 +1055,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, > int flags) > { > nodemask_t nmask; > + struct vm_area_struct *vma; > LIST_HEAD(pagelist); > int err = 0; > struct migration_target_control mtc = { > @@ -1068,8 +1071,9 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, > * need migration. Between passing in the full user address > * space range and MPOL_MF_DISCONTIG_OK, this call can not fail. > */ > + vma = find_vma(mm, 0); > VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))); > - queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask, > + queue_pages_range(mm, vma->vm_start, mm->task_size, &nmask, > flags | MPOL_MF_DISCONTIG_OK, &pagelist); > > if (!list_empty(&pagelist)) { > @@ -1198,13 +1202,12 @@ static struct page *new_page(struct page *page, unsigned long start) > { > struct vm_area_struct *vma; > unsigned long address; > + MA_STATE(mas, ¤t->mm->mm_mt, start, start); > > - vma = find_vma(current->mm, start); > - while (vma) { > + mas_for_each(&mas, vma, ULONG_MAX) { > address = page_address_in_vma(page, vma); > if (address != -EFAULT) > break; > - vma = vma->vm_next; > } > > if (PageHuge(page)) {