| Message ID | 20140922200547.19909.68196.stgit@build.ogc.int (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> > diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h > > index c419498..a9cf5c3 100644 > > --- a/net/sunrpc/xprtrdma/xprt_rdma.h > > +++ b/net/sunrpc/xprtrdma/xprt_rdma.h > > @@ -392,4 +392,8 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; > > /* Workqueue created in svc_rdma.c */ > > extern struct workqueue_struct *svc_rdma_wq; > > > > +#define RPCSVC_MAXPAYLOAD_RDMA \ > > + (RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) ? \ > > + RPCSVC_MAXPAYLOAD : (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)) > > + > > Couldn't you use: > > #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > #define RPCSVC_MAXPAYLOAD_RDMA RPC_MAXPAYLOAD > #else > #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > #endif > > That seems more idiomatic. Sure. That makes it easier to read in my opinion too. I'll send out V3 with this change. Thanks, Steve. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Sep 23, 2014 at 02:42:34PM -0500, Steve Wise wrote: > > > > diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h > > > index c419498..a9cf5c3 100644 > > > --- a/net/sunrpc/xprtrdma/xprt_rdma.h > > > +++ b/net/sunrpc/xprtrdma/xprt_rdma.h > > > @@ -392,4 +392,8 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; > > > /* Workqueue created in svc_rdma.c */ > > > extern struct workqueue_struct *svc_rdma_wq; > > > > > > +#define RPCSVC_MAXPAYLOAD_RDMA \ > > > + (RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) ? \ > > > + RPCSVC_MAXPAYLOAD : (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)) > > > + > > > > Couldn't you use: > > > > #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > #define RPCSVC_MAXPAYLOAD_RDMA RPC_MAXPAYLOAD > > #else > > #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > #endif > > > > That seems more idiomatic. > > Sure. That makes it easier to read in my opinion too. > > I'll send out V3 with this change. While we're bikeshedding, why not use min()? --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: 'J. Bruce Fields' [mailto:bfields@fieldses.org] > Sent: Tuesday, September 23, 2014 2:48 PM > To: Steve Wise > Cc: 'Chuck Lever'; linux-nfs@vger.kernel.org; linux-rdma@vger.kernel.org > Subject: Re: [PATCH V2] svcrdma: Advertise the correct max payload > > On Tue, Sep 23, 2014 at 02:42:34PM -0500, Steve Wise wrote: > > > > > > diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h > > > > index c419498..a9cf5c3 100644 > > > > --- a/net/sunrpc/xprtrdma/xprt_rdma.h > > > > +++ b/net/sunrpc/xprtrdma/xprt_rdma.h > > > > @@ -392,4 +392,8 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; > > > > /* Workqueue created in svc_rdma.c */ > > > > extern struct workqueue_struct *svc_rdma_wq; > > > > > > > > +#define RPCSVC_MAXPAYLOAD_RDMA \ > > > > + (RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) ? \ > > > > + RPCSVC_MAXPAYLOAD : (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)) > > > > + > > > > > > Couldn't you use: > > > > > > #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > > #define RPCSVC_MAXPAYLOAD_RDMA RPC_MAXPAYLOAD > > > #else > > > #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > > #endif > > > > > > That seems more idiomatic. > > > > Sure. That makes it easier to read in my opinion too. > > > > I'll send out V3 with this change. > > While we're bikeshedding, why not use min()? > > --b. I tried that initially. But min() and min_t() don't work because of the way we use the #define. With it defined thusly: #define RPCSVC_MAXPAYLOAD_RDMA min(RPC_MAXPAYLOAD, RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) I see this error: CC [M] net/sunrpc/xprtrdma/svc_rdma_transport.o net/sunrpc/xprtrdma/svc_rdma_transport.c:94: error: braced-group within expression allowed only inside a function make[3]: *** [net/sunrpc/xprtrdma/svc_rdma_transport.o] Error 1 make[2]: *** [net/sunrpc/xprtrdma] Error 2 make[1]: *** [net/sunrpc] Error 2 make: *** [net] Error 2 min() looks like this: #define min(x, y) ({ \ typeof(x) _min1 = (x); \ typeof(y) _min2 = (y); \ (void) (&_min1 == &_min2); \ _min1 < _min2 ? _min1 : _min2; }) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Sep 23, 2014 at 02:53:28PM -0500, Steve Wise wrote: > > > > -----Original Message----- > > From: 'J. Bruce Fields' [mailto:bfields@fieldses.org] > > Sent: Tuesday, September 23, 2014 2:48 PM > > To: Steve Wise > > Cc: 'Chuck Lever'; linux-nfs@vger.kernel.org; linux-rdma@vger.kernel.org > > Subject: Re: [PATCH V2] svcrdma: Advertise the correct max payload > > > > On Tue, Sep 23, 2014 at 02:42:34PM -0500, Steve Wise wrote: > > > > > > > > diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h > > > > > index c419498..a9cf5c3 100644 > > > > > --- a/net/sunrpc/xprtrdma/xprt_rdma.h > > > > > +++ b/net/sunrpc/xprtrdma/xprt_rdma.h > > > > > @@ -392,4 +392,8 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; > > > > > /* Workqueue created in svc_rdma.c */ > > > > > extern struct workqueue_struct *svc_rdma_wq; > > > > > > > > > > +#define RPCSVC_MAXPAYLOAD_RDMA \ > > > > > + (RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) ? \ > > > > > + RPCSVC_MAXPAYLOAD : (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)) > > > > > + > > > > > > > > Couldn't you use: > > > > > > > > #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > > > #define RPCSVC_MAXPAYLOAD_RDMA RPC_MAXPAYLOAD > > > > #else > > > > #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > > > #endif > > > > > > > > That seems more idiomatic. > > > > > > Sure. That makes it easier to read in my opinion too. > > > > > > I'll send out V3 with this change. > > > > While we're bikeshedding, why not use min()? > > > > --b. > > I tried that initially. But min() and min_t() don't work because of the way we use the #define. With it defined thusly: OK, OK. Whatever works.--b. > > #define RPCSVC_MAXPAYLOAD_RDMA min(RPC_MAXPAYLOAD, RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) > > I see this error: > > CC [M] net/sunrpc/xprtrdma/svc_rdma_transport.o > net/sunrpc/xprtrdma/svc_rdma_transport.c:94: error: braced-group within expression allowed only inside a function > make[3]: *** [net/sunrpc/xprtrdma/svc_rdma_transport.o] Error 1 > make[2]: *** [net/sunrpc/xprtrdma] Error 2 > make[1]: *** [net/sunrpc] Error 2 > make: *** [net] Error 2 > > min() looks like this: > > #define min(x, y) ({ \ > typeof(x) _min1 = (x); \ > typeof(y) _min2 = (y); \ > (void) (&_min1 == &_min2); \ > _min1 < _min2 ? _min1 : _min2; }) > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 374feb4..4e61880 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -91,7 +91,7 @@ struct svc_xprt_class svc_rdma_class = { .xcl_name = "rdma", .xcl_owner = THIS_MODULE, .xcl_ops = &svc_rdma_ops, - .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, + .xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA, .xcl_ident = XPRT_TRANSPORT_RDMA, }; diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h index c419498..a9cf5c3 100644 --- a/net/sunrpc/xprtrdma/xprt_rdma.h +++ b/net/sunrpc/xprtrdma/xprt_rdma.h @@ -392,4 +392,8 @@ extern struct kmem_cache *svc_rdma_ctxt_cachep; /* Workqueue created in svc_rdma.c */ extern struct workqueue_struct *svc_rdma_wq; +#define RPCSVC_MAXPAYLOAD_RDMA \ + (RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT) ? \ + RPCSVC_MAXPAYLOAD : (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)) + #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */
Svcrdma currently advertises 1MB, which is too large. The correct value is the minimum of RPCSVC_MAXPAYLOAD and the max scatter-gather allowed in an NFSRDMA IO chunk * the host page size. This bug is usually benign because the Linux X64 NFSRDMA client correctly limits the payload size to the correct value (64*4096 = 256KB). But if the Linux client is PPC64 with a 64KB page size, then the client will indeed use a payload size that will overflow the server. Signed-off-by: Steve Wise <swise@opengridcomputing.com> --- net/sunrpc/xprtrdma/svc_rdma_transport.c | 2 +- net/sunrpc/xprtrdma/xprt_rdma.h | 4 ++++ 2 files changed, 5 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html