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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3682C4363C for ; Mon, 21 Sep 2020 19:12:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A2C7216C4 for ; Mon, 21 Sep 2020 19:12:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mehcTMqJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728015AbgIUTMQ (ORCPT ); Mon, 21 Sep 2020 15:12:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726886AbgIUTMQ (ORCPT ); Mon, 21 Sep 2020 15:12:16 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E052BC061755 for ; Mon, 21 Sep 2020 12:12:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=8o7GVAomh929Hvy+xaXufBwE8CQqTnicVvJhMbCZ9+k=; b=mehcTMqJtwQu3rPUjsEisC7ECq 7+58K3Z4EekBFXZ3wYEUeQuCa/fWdcNhiPeHAeErok/v8ZUYK3e3gg5/B4dsAsGOOcHKMJll0ZrgT uIxyCNSUGOAg2UN4gsizGdkbduG7XDlLurQP7j3hPoeoUDi05V5iO3YFhaKjX5x3pQ8mdKFxJmqgA L9SsTOYSux1ZLBO0Whate1mY/A8G4ym2vhOpFFpaMiIWVUAzrHfwOrb8cuL3VnUqrmtLSbCIIumHR mHpwBBr1xVe0+QICrLKcrhz2TwTDJC2BnukZFO6wyPDyqecyMJcK7af7LQwFO3njp1VzvRCXlr6uE ADgc0Q1w==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKRED-0003Cg-2P; Mon, 21 Sep 2020 19:11:57 +0000 Date: Mon, 21 Sep 2020 20:11:57 +0100 From: Matthew Wilcox To: Christoph Hellwig Cc: Andrew Morton , Peter Zijlstra , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Minchan Kim , Nitin Gupta , x86@kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: [PATCH 3/6] drm/i915: use vmap in shmem_pin_map Message-ID: <20200921191157.GX32101@casper.infradead.org> References: <20200918163724.2511-1-hch@lst.de> <20200918163724.2511-4-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200918163724.2511-4-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 18, 2020 at 06:37:21PM +0200, Christoph Hellwig wrote: > void shmem_unpin_map(struct file *file, void *ptr) > { > + long i = shmem_npages(file); > + > mapping_clear_unevictable(file->f_mapping); > - __shmem_unpin_map(file, ptr, shmem_npte(file)); > + vunmap(ptr); > + > + for (i = 0; i < shmem_npages(file); i++) { > + struct page *page; > + > + page = shmem_read_mapping_page_gfp(file->f_mapping, i, > + GFP_KERNEL); > + if (!WARN_ON(IS_ERR(page))) { > + put_page(page); > + put_page(page); > + } > + } > } This is awkward. I'd like it if we had a vfree() variant which called put_page() instead of __free_pages(). I'd like it even more if we used release_pages() instead of our own loop that called put_page(). Perhaps something like this ... +++ b/mm/vmalloc.c @@ -2262,7 +2262,7 @@ static void __vunmap(const void *addr, int deallocate_page s) vm_remove_mappings(area, deallocate_pages); - if (deallocate_pages) { + if (deallocate_pages == 1) { int i; for (i = 0; i < area->nr_pages; i++) { @@ -2271,8 +2271,12 @@ static void __vunmap(const void *addr, int deallocate_pages) BUG_ON(!page); __free_pages(page, 0); } - atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); + } else if (deallocate_pages == 2) { + release_pages(area->pages, area->nr_pages); + } + if (deallocate_pages) { + atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); kvfree(area->pages); } @@ -2369,6 +2373,14 @@ void vunmap(const void *addr) } EXPORT_SYMBOL(vunmap); +void vunmap_put_pages(const void *addr) +{ + BUG_ON(in_interrupt()); + might_sleep(); + if (addr) + __vunmap(addr, 2); +} + /** * vmap - map an array of pages into virtually contiguous space * @pages: array of page pointers only with kernel-doc and so on. I bet somebody has a better idea for a name.