From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Venkateswararao Jujjuri (JV)" Subject: [PATCH] [net/9p] Small non-IO PDUs for zero-copy supporting transports. Date: Thu, 17 Feb 2011 14:12:41 -0800 Message-ID: <1297980761-28579-1-git-send-email-jvrao@linux.vnet.ibm.com> Cc: linux-fsdevel@vger.kernel.org, "Venkateswararao Jujjuri (JV)" To: v9fs-developer@lists.sourceforge.net Return-path: Received: from e38.co.us.ibm.com ([32.97.110.159]:35150 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752053Ab1BQVez (ORCPT ); Thu, 17 Feb 2011 16:34:55 -0500 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e38.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p1HLKQKX001188 for ; Thu, 17 Feb 2011 14:20:26 -0700 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id p1HLYodt090550 for ; Thu, 17 Feb 2011 14:34:50 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p1HLYnIj019481 for ; Thu, 17 Feb 2011 14:34:50 -0700 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: If a transport prefers payload to be sent separate from the PDU (P9_TRANS_PREF_PAYLOAD_SEP), there is no need to allocate msize PDU buffers(struct p9_fcall). This patch allocates only upto 4k buffers for this kind of transports and there won't be any change to the legacy transports. Hence, this patch on top of zero copy changes allows user to specify higher msizes through the mount option without hogging the kernel heap. Signed-off-by: Venkateswararao Jujjuri --- include/net/9p/9p.h | 2 +- net/9p/client.c | 23 +++++++++++++++++------ 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h index 7aefa6d..eaa45f9 100644 --- a/include/net/9p/9p.h +++ b/include/net/9p/9p.h @@ -688,7 +688,7 @@ struct p9_rwstat { * @id: protocol operating identifier of type &p9_msg_t * @tag: transaction id of the request * @offset: used by marshalling routines to track currentposition in buffer - * @capacity: used by marshalling routines to track total capacity + * @capacity: used by marshalling routines to track total malloc'd capacity * @pubuf: Payload user buffer given by the caller * @pubuf: Payload kernel buffer given by the caller * @pbuf_size: pubuf/pkbuf(only one will be !NULL) size to be read/write. diff --git a/net/9p/client.c b/net/9p/client.c index 251abb1..43ec78a 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -229,10 +229,23 @@ static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag) return ERR_PTR(-ENOMEM); } init_waitqueue_head(req->wq); - req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize, - GFP_KERNEL); - req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize, - GFP_KERNEL); + if ((c->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) == + P9_TRANS_PREF_PAYLOAD_SEP) { + int alloc_msize = min(c->msize, 4096); + req->tc = kmalloc(sizeof(struct p9_fcall)+alloc_msize, + GFP_KERNEL); + req->tc->capacity = alloc_msize; + req->rc = kmalloc(sizeof(struct p9_fcall)+alloc_msize, + GFP_KERNEL); + req->rc->capacity = alloc_msize; + } else { + req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize, + GFP_KERNEL); + req->tc->capacity = c->msize; + req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize, + GFP_KERNEL); + req->rc->capacity = c->msize; + } if ((!req->tc) || (!req->rc)) { printk(KERN_ERR "Couldn't grow tag array\n"); kfree(req->tc); @@ -243,9 +256,7 @@ static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag) return ERR_PTR(-ENOMEM); } req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall); - req->tc->capacity = c->msize; req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall); - req->rc->capacity = c->msize; } p9pdu_reset(req->tc); -- 1.6.5.2