From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Wise Subject: Re: [PATCH V3 01/17] xprtrdma: mind the device's max fast register page list depth Date: Fri, 16 May 2014 09:14:00 -0500 Message-ID: <53761D28.3070704@opengridcomputing.com> References: <20140430191433.5663.16217.stgit@manet.1015granger.net> <20140430192936.5663.66537.stgit@manet.1015granger.net> <53761C63.4050908@opengridcomputing.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <53761C63.4050908-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Devesh Sharma , Chuck Lever , "linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: "Anna.Schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org By the way, Devesh: Is the device advertising FRMR support, yet settin= g=20 the max page list len to zero? That's a driver bug... On 5/16/2014 9:10 AM, Steve Wise wrote: > I guess the client code doesn't verify that the device supports the=20 > chosen memreg mode. That's not good. Lemme fix this and respin thi= s=20 > patch. > > > On 5/16/2014 2:08 AM, Devesh Sharma wrote: >> Chuck >> >> This patch is causing a CPU soft-lockup if underlying vendor reports= =20 >> devattr.max_fast_reg_pagr_list_len =3D 0 and ia->ri_memreg_strategy = =3D=20 >> FRMR (Default option). >> I think there is need to refer to device capability flags. If=20 >> strategy =3D FRMR is forced and devattr.max_fast_reg_pagr_list_len=3D= 0=20 >> then flash an error and fail RPC with -EIO. >> >> See inline: >> >>> -----Original Message----- >>> From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma- >>> owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Chuck Lever >>> Sent: Thursday, May 01, 2014 1:00 AM >>> To: linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >>> Cc: Anna.Schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org >>> Subject: [PATCH V3 01/17] xprtrdma: mind the device's max fast regi= ster >>> page list depth >>> >>> From: Steve Wise >>> >>> Some rdma devices don't support a fast register page list depth of=20 >>> at least >>> RPCRDMA_MAX_DATA_SEGS. So xprtrdma needs to chunk its fast registe= r >>> regions according to the minimum of the device max supported depth = or >>> RPCRDMA_MAX_DATA_SEGS. >>> >>> Signed-off-by: Steve Wise >>> Reviewed-by: Chuck Lever >>> --- >>> >>> net/sunrpc/xprtrdma/rpc_rdma.c | 4 --- >>> net/sunrpc/xprtrdma/verbs.c | 47 ++++++++++++++++++++++++++= +++- >>> --------- >>> net/sunrpc/xprtrdma/xprt_rdma.h | 1 + >>> 3 files changed, 36 insertions(+), 16 deletions(-) >>> >>> diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c >>> b/net/sunrpc/xprtrdma/rpc_rdma.c index 96ead52..400aa1b 100644 >>> --- a/net/sunrpc/xprtrdma/rpc_rdma.c >>> +++ b/net/sunrpc/xprtrdma/rpc_rdma.c >>> @@ -248,10 +248,6 @@ rpcrdma_create_chunks(struct rpc_rqst *rqst,=20 >>> struct >>> xdr_buf *target, >>> /* success. all failures return above */ >>> req->rl_nchunks =3D nchunks; >>> >>> - BUG_ON(nchunks =3D=3D 0); >>> - BUG_ON((r_xprt->rx_ia.ri_memreg_strategy =3D=3D RPCRDMA_FRMR) >>> - && (nchunks > 3)); >>> - >>> /* >>> * finish off header. If write, marshal discrim and nchunks. >>> */ >>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verb= s.c >>> index 9372656..55fb09a 100644 >>> --- a/net/sunrpc/xprtrdma/verbs.c >>> +++ b/net/sunrpc/xprtrdma/verbs.c >>> @@ -539,6 +539,11 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, str= uct >>> sockaddr *addr, int memreg) >>> __func__); >>> memreg =3D RPCRDMA_REGISTER; >>> #endif >>> + } else { >>> + /* Mind the ia limit on FRMR page list depth */ >>> + ia->ri_max_frmr_depth =3D min_t(unsigned int, >>> + RPCRDMA_MAX_DATA_SEGS, >>> + devattr.max_fast_reg_page_list_len); >>> } >>> break; >>> } >>> @@ -659,24 +664,42 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep, stru= ct >>> rpcrdma_ia *ia, >>> ep->rep_attr.srq =3D NULL; >>> ep->rep_attr.cap.max_send_wr =3D cdata->max_requests; >>> switch (ia->ri_memreg_strategy) { >>> - case RPCRDMA_FRMR: >>> + case RPCRDMA_FRMR: { >>> + int depth =3D 7; >>> + >>> /* Add room for frmr register and invalidate WRs. >>> * 1. FRMR reg WR for head >>> * 2. FRMR invalidate WR for head >>> - * 3. FRMR reg WR for pagelist >>> - * 4. FRMR invalidate WR for pagelist >>> + * 3. N FRMR reg WRs for pagelist >>> + * 4. N FRMR invalidate WRs for pagelist >>> * 5. FRMR reg WR for tail >>> * 6. FRMR invalidate WR for tail >>> * 7. The RDMA_SEND WR >>> */ >>> - ep->rep_attr.cap.max_send_wr *=3D 7; >>> + >>> + /* Calculate N if the device max FRMR depth is smaller tha= n >>> + * RPCRDMA_MAX_DATA_SEGS. >>> + */ >>> + if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) { >>> + int delta =3D RPCRDMA_MAX_DATA_SEGS - >>> + ia->ri_max_frmr_depth; >>> + >>> + do { >>> + depth +=3D 2; /* FRMR reg + invalidate */ >>> + delta -=3D ia->ri_max_frmr_depth; >> If ia->ri_max_frmr_depth is =3D 0. This loop becomes infinite loop. >> >>> + } while (delta > 0); >>> + >>> + } >>> + ep->rep_attr.cap.max_send_wr *=3D depth; >>> if (ep->rep_attr.cap.max_send_wr > devattr.max_qp_wr) { >>> - cdata->max_requests =3D devattr.max_qp_wr / 7; >>> + cdata->max_requests =3D devattr.max_qp_wr / depth; >>> if (!cdata->max_requests) >>> return -EINVAL; >>> - ep->rep_attr.cap.max_send_wr =3D cdata- >>>> max_requests * 7; >>> + ep->rep_attr.cap.max_send_wr =3D cdata- >>>> max_requests * >>> + depth; >>> } >>> break; >>> + } >>> case RPCRDMA_MEMWINDOWS_ASYNC: >>> case RPCRDMA_MEMWINDOWS: >>> /* Add room for mw_binds+unbinds - overkill! */ @@ - >>> 1043,16 +1066,16 @@ rpcrdma_buffer_create(struct rpcrdma_buffer *bu= f, >>> struct rpcrdma_ep *ep, >>> case RPCRDMA_FRMR: >>> for (i =3D buf->rb_max_requests * RPCRDMA_MAX_SEGS; i; i-= - >>> ) { >>> r->r.frmr.fr_mr =3D ib_alloc_fast_reg_mr(ia->ri_pd, >>> - >>> RPCRDMA_MAX_SEGS); >>> + ia->ri_max_frmr_depth); >>> if (IS_ERR(r->r.frmr.fr_mr)) { >>> rc =3D PTR_ERR(r->r.frmr.fr_mr); >>> dprintk("RPC: %s: ib_alloc_fast_reg_mr" >>> " failed %i\n", __func__, rc); >>> goto out; >>> } >>> - r->r.frmr.fr_pgl =3D >>> - ib_alloc_fast_reg_page_list(ia->ri_id- >>>> device, >>> - >>> RPCRDMA_MAX_SEGS); >>> + r->r.frmr.fr_pgl =3D ib_alloc_fast_reg_page_list( >>> + ia->ri_id->device, >>> + ia->ri_max_frmr_depth); >>> if (IS_ERR(r->r.frmr.fr_pgl)) { >>> rc =3D PTR_ERR(r->r.frmr.fr_pgl); >>> dprintk("RPC: %s: " >>> @@ -1498,8 +1521,8 @@ rpcrdma_register_frmr_external(struct >>> rpcrdma_mr_seg *seg, >>> seg1->mr_offset -=3D pageoff; /* start of page */ >>> seg1->mr_len +=3D pageoff; >>> len =3D -pageoff; >>> - if (*nsegs > RPCRDMA_MAX_DATA_SEGS) >>> - *nsegs =3D RPCRDMA_MAX_DATA_SEGS; >>> + if (*nsegs > ia->ri_max_frmr_depth) >>> + *nsegs =3D ia->ri_max_frmr_depth; >>> for (page_no =3D i =3D 0; i < *nsegs;) { >>> rpcrdma_map_one(ia, seg, writing); >>> pa =3D seg->mr_dma; >>> diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h >>> b/net/sunrpc/xprtrdma/xprt_rdma.h index cc1445d..98340a3 100644 >>> --- a/net/sunrpc/xprtrdma/xprt_rdma.h >>> +++ b/net/sunrpc/xprtrdma/xprt_rdma.h >>> @@ -66,6 +66,7 @@ struct rpcrdma_ia { >>> struct completion ri_done; >>> int ri_async_rc; >>> enum rpcrdma_memreg ri_memreg_strategy; >>> + unsigned int ri_max_frmr_depth; >>> }; >>> >>> /* >>> >>> --=20 >>> To unsubscribe from this list: send the line "unsubscribe=20 >>> linux-rdma" in the >>> body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info = at >>> http://vger.kernel.org/majordomo-info.html >> N=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BDr=EF=BF=BD=EF=BF=BDy=EF= =BF=BD=EF=BF=BD=EF=BF=BDb=EF=BF=BDX=EF=BF=BD=EF=BF=BD=C7=A7v=EF=BF=BD^=EF= =BF=BD)=DE=BA{.n=EF=BF=BD+=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD{=EF=BF=BD= =EF=BF=BD=EF=BF=BD"=EF=BF=BD=EF=BF=BD^n=EF=BF=BDr=EF=BF=BD=EF=BF=BD=EF=BF= =BDz=EF=BF=BD=1A =EF=BF=BD=EF=BF=BDh=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD= &=EF=BF=BD=EF=BF=BD=1E=20 >> =EF=BF=BDG=EF=BF=BD=EF=BF=BD=EF=BF=BDh=EF=BF=BD=03(=EF=BF=BD=E9=9A=8E= =EF=BF=BD=DD=A2j"=EF=BF=BD=EF=BF=BD=1A=EF=BF=BD=1Bm=EF=BF=BD=EF=BF=BD=EF= =BF=BD=EF=BF=BD=EF=BF=BDz=EF=BF=BD=DE=96=EF=BF=BD=EF=BF=BD=EF=BF=BDf=EF= =BF=BD=EF=BF=BD=EF=BF=BDh=EF=BF=BD=EF=BF=BD=EF=BF=BD~=EF=BF=BDmml=3D=3D > > --=20 > To unsubscribe from this list: send the line "unsubscribe linux-rdma"= in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html