From f735195d51e10b2550097f7b0ac12219060e962b Mon Sep 17 00:00:00 2001 From: "Venkateswararao Jujjuri (JV)" Date: Wed, 16 Feb 2011 12:54:22 -0800 Subject: [net/9p] Small non-IO PDUs for zero-copy supporting transports. 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 Signed-off-by: Eric Van Hensbergen --- 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 7aefa6d975ac..eaa45f932970 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 251abb1699c4..43ec78af4547 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); -- cgit v1.2.3