2008-05-30 18:46:57

by [email protected]

[permalink] [raw]
Subject: Re: [PATCH 0/3] [RFC] knfsd: convert to kthread API and remove signaling for shutdown

On Fri, May 30, 2008 at 12:25:17PM -0400, Jeff Layton wrote:
> On Tue, 20 May 2008 20:29:52 -0700
> Greg Banks <gnb-cP1dWloDopni96+mSzHFpQC/[email protected]> wrote:
>
> > Jeff Layton wrote:
> > >
> > > [...] Rather than delaying the allocation like this,
> > > I wonder if we can just figure out the node from the cpumask and then
> > > do a kmalloc_node()?
> > >
> > >
> > Sure.
> >
>
> I started to do this patch as part of the kthread conversion, but it's
> actually pretty independent. We can probably treat it separately.
> This hasn't been tested on an actual NUMA machine yet, but any thoughts
> on the following patch?
>
> -----------------[snip]-------------------
>
> >From 46432a021fe1931f4a44587124ac9442e83c4731 Mon Sep 17 00:00:00 2001
> From: Jeff Layton <[email protected]>
> Date: Fri, 30 May 2008 11:57:18 -0400
> Subject: [PATCH] sunrpc: have pooled services make NUMA-friendly allocations
>
> Currently, svc_prepare_thread allocates memory using plain kmalloc()
> and alloc_page() calls, even for threads that are destined to run on
> different CPUs or NUMA nodes than the current one. Add a function to
> translate a poolid into a NUMA node, and have svc_prepare_thread and
> svc_init_buffer allocate memory on those nodes instead.
>
> Signed-off-by: Jeff Layton <[email protected]>
> ---
> net/sunrpc/svc.c | 46 ++++++++++++++++++++++++++++++++++++++++------
> 1 files changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> index 01c7e31..3985fbc 100644
> --- a/net/sunrpc/svc.c
> +++ b/net/sunrpc/svc.c
> @@ -332,6 +332,32 @@ svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask)
> }
>
> /*
> + * for a given poolid, return the NUMA memory node. This allows us to
> + * allocate memory close to the CPU's where the task will be running
> + */
> +static inline unsigned int
> +svc_pool_to_node(unsigned int pidx)
> +{
> + struct svc_pool_map *m = &svc_pool_map;
> + unsigned int poolnode = m->pool_to[pidx];
> +
> + /*
> + * The caller checks for sv_nrpools > 1, which
> + * implies that we've been initialized.
> + */
> + BUG_ON(m->count == 0);
> +
> + switch (m->mode) {
> + case SVC_POOL_PERNODE:
> + return poolnode;
> + case SVC_POOL_PERCPU:
> + return cpu_to_node(poolnode);
> + }
> +
> + return numa_node_id();
> +}
> +
> +/*
> * Use the mapping mode to choose a pool for a given CPU.
> * Used when enqueueing an incoming RPC. Always returns
> * a non-NULL pool pointer.
> @@ -507,7 +533,7 @@ EXPORT_SYMBOL(svc_destroy);
> * We allocate pages and place them in rq_argpages.
> */
> static int
> -svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
> +svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, unsigned int node)
> {
> unsigned int pages, arghi;
>
> @@ -517,7 +543,7 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
> arghi = 0;
> BUG_ON(pages > RPCSVC_MAXPAGES);
> while (pages) {
> - struct page *p = alloc_page(GFP_KERNEL);
> + struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
> if (!p)
> break;
> rqstp->rq_pages[arghi++] = p;
> @@ -543,8 +569,14 @@ struct svc_rqst *
> svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
> {
> struct svc_rqst *rqstp;
> + unsigned int node;
> +
> + if (serv->sv_nrpools > 1)
> + node = svc_pool_to_node(pool->sp_id);
> + else
> + node = numa_node_id();
>
> - rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
> + rqstp = kmalloc_node(sizeof(*rqstp), GFP_KERNEL | __GFP_ZERO, node);
> if (!rqstp)
> goto out_enomem;
>
> @@ -558,15 +590,17 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
> rqstp->rq_server = serv;
> rqstp->rq_pool = pool;
>
> - rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
> + rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize,
> + GFP_KERNEL | __GFP_ZERO, node);
> if (!rqstp->rq_argp)
> goto out_thread;
>
> - rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
> + rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize,
> + GFP_KERNEL | __GFP_ZERO, node);

Why the __GFP_ZERO's on these last two?

--b.

> if (!rqstp->rq_resp)
> goto out_thread;
>
> - if (!svc_init_buffer(rqstp, serv->sv_max_mesg))
> + if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
> goto out_thread;
>
> return rqstp;
> --
> 1.5.3.6
>
> _______________________________________________
> NFSv4 mailing list
> [email protected]
> http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4


2008-05-30 20:59:13

by Jeff Layton

[permalink] [raw]
Subject: Re: [PATCH 0/3] [RFC] knfsd: convert to kthread API and remove signaling for shutdown

On Fri, 30 May 2008 14:46:53 -0400
"J. Bruce Fields" <[email protected]> wrote:

> On Fri, May 30, 2008 at 12:25:17PM -0400, Jeff Layton wrote:
> > On Tue, 20 May 2008 20:29:52 -0700
> > Greg Banks <[email protected]> wrote:
> >
> > > Jeff Layton wrote:
> > > >
> > > > [...] Rather than delaying the allocation like this,
> > > > I wonder if we can just figure out the node from the cpumask and then
> > > > do a kmalloc_node()?
> > > >
> > > >
> > > Sure.
> > >
> >
> > I started to do this patch as part of the kthread conversion, but it's
> > actually pretty independent. We can probably treat it separately.
> > This hasn't been tested on an actual NUMA machine yet, but any thoughts
> > on the following patch?
> >
> > -----------------[snip]-------------------
> >
> > >From 46432a021fe1931f4a44587124ac9442e83c4731 Mon Sep 17 00:00:00 2001
> > From: Jeff Layton <[email protected]>
> > Date: Fri, 30 May 2008 11:57:18 -0400
> > Subject: [PATCH] sunrpc: have pooled services make NUMA-friendly allocations
> >
> > Currently, svc_prepare_thread allocates memory using plain kmalloc()
> > and alloc_page() calls, even for threads that are destined to run on
> > different CPUs or NUMA nodes than the current one. Add a function to
> > translate a poolid into a NUMA node, and have svc_prepare_thread and
> > svc_init_buffer allocate memory on those nodes instead.
> >
> > Signed-off-by: Jeff Layton <[email protected]>
> > ---
> > net/sunrpc/svc.c | 46 ++++++++++++++++++++++++++++++++++++++++------
> > 1 files changed, 40 insertions(+), 6 deletions(-)
> >
> > diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
> > index 01c7e31..3985fbc 100644
> > --- a/net/sunrpc/svc.c
> > +++ b/net/sunrpc/svc.c
> > @@ -332,6 +332,32 @@ svc_pool_map_set_cpumask(unsigned int pidx, cpumask_t *oldmask)
> > }
> >
> > /*
> > + * for a given poolid, return the NUMA memory node. This allows us to
> > + * allocate memory close to the CPU's where the task will be running
> > + */
> > +static inline unsigned int
> > +svc_pool_to_node(unsigned int pidx)
> > +{
> > + struct svc_pool_map *m = &svc_pool_map;
> > + unsigned int poolnode = m->pool_to[pidx];
> > +
> > + /*
> > + * The caller checks for sv_nrpools > 1, which
> > + * implies that we've been initialized.
> > + */
> > + BUG_ON(m->count == 0);
> > +
> > + switch (m->mode) {
> > + case SVC_POOL_PERNODE:
> > + return poolnode;
> > + case SVC_POOL_PERCPU:
> > + return cpu_to_node(poolnode);
> > + }
> > +
> > + return numa_node_id();
> > +}
> > +
> > +/*
> > * Use the mapping mode to choose a pool for a given CPU.
> > * Used when enqueueing an incoming RPC. Always returns
> > * a non-NULL pool pointer.
> > @@ -507,7 +533,7 @@ EXPORT_SYMBOL(svc_destroy);
> > * We allocate pages and place them in rq_argpages.
> > */
> > static int
> > -svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
> > +svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, unsigned int node)
> > {
> > unsigned int pages, arghi;
> >
> > @@ -517,7 +543,7 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
> > arghi = 0;
> > BUG_ON(pages > RPCSVC_MAXPAGES);
> > while (pages) {
> > - struct page *p = alloc_page(GFP_KERNEL);
> > + struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
> > if (!p)
> > break;
> > rqstp->rq_pages[arghi++] = p;
> > @@ -543,8 +569,14 @@ struct svc_rqst *
> > svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
> > {
> > struct svc_rqst *rqstp;
> > + unsigned int node;
> > +
> > + if (serv->sv_nrpools > 1)
> > + node = svc_pool_to_node(pool->sp_id);
> > + else
> > + node = numa_node_id();
> >
> > - rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
> > + rqstp = kmalloc_node(sizeof(*rqstp), GFP_KERNEL | __GFP_ZERO, node);
> > if (!rqstp)
> > goto out_enomem;
> >
> > @@ -558,15 +590,17 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool)
> > rqstp->rq_server = serv;
> > rqstp->rq_pool = pool;
> >
> > - rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
> > + rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize,
> > + GFP_KERNEL | __GFP_ZERO, node);
> > if (!rqstp->rq_argp)
> > goto out_thread;
> >
> > - rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL);
> > + rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize,
> > + GFP_KERNEL | __GFP_ZERO, node);
>
> Why the __GFP_ZERO's on these last two?
>
> --b.
>

Uhhh...because I worked on this just before going to bed? Good catch.
I think those flags can be removed...

> > if (!rqstp->rq_resp)
> > goto out_thread;
> >
> > - if (!svc_init_buffer(rqstp, serv->sv_max_mesg))
> > + if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
> > goto out_thread;
> >
> > return rqstp;
> > --
> > 1.5.3.6
> >
> > _______________________________________________
> > NFSv4 mailing list
> > [email protected]
> > http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4


--
Jeff Layton <[email protected]>