From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759961AbYDPT43 (ORCPT ); Wed, 16 Apr 2008 15:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753081AbYDPT4Q (ORCPT ); Wed, 16 Apr 2008 15:56:16 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60453 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbYDPT4P (ORCPT ); Wed, 16 Apr 2008 15:56:15 -0400 Message-ID: <480658DC.6030507@redhat.com> Date: Wed, 16 Apr 2008 15:51:56 -0400 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Pekka J Enberg , Tom Zanussi , David Wilder , Andrew Morton CC: systemtap-ml , LKML , tzanussi@gmail.com Subject: [PATCH -mm] relayfs: support larger relay buffer take 3 References: <4804C95F.2080204@redhat.com> <1208319769.7893.16.camel@charm-linux> <48063F80.9060404@redhat.com> <480646B2.9000905@redhat.com> In-Reply-To: <480646B2.9000905@redhat.com> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use vmalloc() and memset() instead of kcalloc() to allocate a page* array when the array size is bigger than one page. This enables relayfs to support bigger relay buffers than 64MB on 4k-page system, 512MB on 16k-page system. Signed-off-by: Masami Hiramatsu --- Changes from take2 to take3: - Use struct page ** instead of struct page *. - move functions to the place before relay_mmap_buf. - add comments. This is useful for a 64-bit system which has a plenty of memory (tens of giga bytes) and a large kernel memory space. I tested it on x86-64 and ia64. kernel/relay.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) Index: 2.6.25-rc8-mm2/kernel/relay.c =================================================================== --- 2.6.25-rc8-mm2.orig/kernel/relay.c +++ 2.6.25-rc8-mm2/kernel/relay.c @@ -65,6 +65,35 @@ static struct vm_operations_struct relay .close = relay_file_mmap_close, }; +/* + * allocate an array of pointers of struct page + */ +static struct page **relay_alloc_page_array(unsigned int n_pages) +{ + struct page **array; + unsigned int pa_size = n_pages * sizeof(struct page *); + + if (pa_size > PAGE_SIZE) { + array = vmalloc(pa_size); + if (array) + memset(array, 0, pa_size); + } else { + array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); + } + return array; +} + +/* + * free an array of pointers of struct page + */ +static void relay_free_page_array(struct page **array) +{ + if (is_vmalloc_addr(array)) + vfree(array); + else + kfree(array); +} + /** * relay_mmap_buf: - mmap channel buffer to process address space * @buf: relay channel buffer @@ -109,7 +138,7 @@ static void *relay_alloc_buf(struct rcha *size = PAGE_ALIGN(*size); n_pages = *size >> PAGE_SHIFT; - buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); + buf->page_array = relay_alloc_page_array(n_pages); if (!buf->page_array) return NULL; @@ -130,7 +159,7 @@ static void *relay_alloc_buf(struct rcha depopulate: for (j = 0; j < i; j++) __free_page(buf->page_array[j]); - kfree(buf->page_array); + relay_free_page_array(buf->page_array); return NULL; } @@ -189,7 +218,7 @@ static void relay_destroy_buf(struct rch vunmap(buf->start); for (i = 0; i < buf->page_count; i++) __free_page(buf->page_array[i]); - kfree(buf->page_array); + relay_free_page_array(buf->page_array); } chan->buf[buf->cpu] = NULL; kfree(buf->padding); -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@redhat.com