From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753292AbYDPEXF (ORCPT ); Wed, 16 Apr 2008 00:23:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750786AbYDPEWx (ORCPT ); Wed, 16 Apr 2008 00:22:53 -0400 Received: from qmta10.westchester.pa.mail.comcast.net ([76.96.62.17]:41513 "EHLO QMTA10.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750778AbYDPEWw (ORCPT ); Wed, 16 Apr 2008 00:22:52 -0400 X-Authority-Analysis: v=1.0 c=1 a=YSWQqB5pQ2wA:10 a=26HdPeMOMtQA:10 a=vGK5CW9ijm8SuqUrLw8A:9 a=09X17OGoLUk09lSJMqgA:7 a=k_3eVp-4zJYpRCH2X5XbKbXvRZEA:4 a=jEp0ucaQiEUA:10 a=WuK_CZDBSqoA:10 Subject: Re: [PATCH -mm] relayfs: support larger relay buffer From: Tom Zanussi To: Masami Hiramatsu Cc: David Wilder , Andrew Morton , systemtap-ml , LKML , tzanussi@gmail.com In-Reply-To: <4804C95F.2080204@redhat.com> References: <4804C95F.2080204@redhat.com> Content-Type: text/plain Date: Tue, 15 Apr 2008 23:22:49 -0500 Message-Id: <1208319769.7893.16.camel@charm-linux> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-04-15 at 11:27 -0400, Masami Hiramatsu wrote: > 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 > --- > 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. > Hi, It looks ok to me, but it might be a little cleaner and avoid some duplication if you add the new code as a couple of functions instead. Just a suggestion... Tom > kernel/relay.c | 22 ++++++++++++++++++---- > 1 file changed, 18 insertions(+), 4 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 > @@ -104,12 +104,20 @@ static int relay_mmap_buf(struct rchan_b > static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) > { > void *mem; > - unsigned int i, j, n_pages; > + unsigned int i, j, n_pages, pa_size; > > *size = PAGE_ALIGN(*size); > n_pages = *size >> PAGE_SHIFT; > + pa_size = n_pages * sizeof(struct page *); > > - buf->page_array = kcalloc(n_pages, sizeof(struct page *), GFP_KERNEL); > + if (pa_size > PAGE_SIZE) { > + buf->page_array = vmalloc(pa_size); > + if (buf->page_array) > + memset(buf->page_array, 0, pa_size); > + } else { > + buf->page_array = kcalloc(n_pages, sizeof(struct page *), > + GFP_KERNEL); > + } > if (!buf->page_array) > return NULL; > > @@ -130,7 +138,10 @@ static void *relay_alloc_buf(struct rcha > depopulate: > for (j = 0; j < i; j++) > __free_page(buf->page_array[j]); > - kfree(buf->page_array); > + if (pa_size > PAGE_SIZE) > + vfree(buf->page_array); > + else > + kfree(buf->page_array); > return NULL; > } > > @@ -189,7 +200,10 @@ 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); > + if (buf->page_count * sizeof(struct page *) > PAGE_SIZE) > + vfree(buf->page_array); > + else > + kfree(buf->page_array); > } > chan->buf[buf->cpu] = NULL; > kfree(buf->padding);