| Message ID | 20180601125321.30652-2-osalvador@techadventures.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 1 Jun 2018 14:53:18 +0200 <osalvador@techadventures.net> wrote: > From: Oscar Salvador <osalvador@suse.de> > > add_memory_resource() contains code to allocate a new node in case > it is necessary. > Since try_online_node() also hast some code for this purpose, > let us make use of that and remove duplicate code. > > This introduces __try_online_node(), which is called by add_memory_resource() > and try_online_node(). > __try_online_node() has two new parameters, start_addr of the node, > and if the node should be onlined and registered right away. > This is always wanted if we are calling from do_cpu_up(), but not > when we are calling from memhotplug code. > Nothing changes from the point of view of the users of try_online_node(), > since try_online_node passes start_addr=0 and online_node=true to > __try_online_node(). > Trivial whitespace issue inline... > Signed-off-by: Oscar Salvador <osalvador@suse.de> > --- > mm/memory_hotplug.c | 61 +++++++++++++++++++++++++++++------------------------ > 1 file changed, 34 insertions(+), 27 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 7deb49f69e27..29a5fc89bdb1 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1034,8 +1034,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) > return pgdat; > } > > -static void rollback_node_hotadd(int nid, pg_data_t *pgdat) > +static void rollback_node_hotadd(int nid) > { > + pg_data_t *pgdat = NODE_DATA(nid); > + > arch_refresh_nodedata(nid, NULL); > free_percpu(pgdat->per_cpu_nodestats); > arch_free_nodedata(pgdat); > @@ -1046,28 +1048,43 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) > /** > * try_online_node - online a node if offlined > * @nid: the node ID > - * > + * @start: start addr of the node > + * @set_node_online: Whether we want to online the node > * called by cpu_up() to online a node without onlined memory. > */ > -int try_online_node(int nid) > +static int __try_online_node(int nid, u64 start, bool set_node_online) > { > - pg_data_t *pgdat; > - int ret; > + pg_data_t *pgdat; > + int ret = 1; > > if (node_online(nid)) > return 0; > > - mem_hotplug_begin(); > - pgdat = hotadd_new_pgdat(nid, 0); > + pgdat = hotadd_new_pgdat(nid, start); > if (!pgdat) { > pr_err("Cannot online node %d due to NULL pgdat\n", nid); > ret = -ENOMEM; > goto out; > } > - node_set_online(nid); > - ret = register_one_node(nid); > - BUG_ON(ret); > + > + if (set_node_online) { > + node_set_online(nid); > + ret = register_one_node(nid); > + BUG_ON(ret); > + } > out: > + return ret; > +} > + > +/* > + * Users of this function always want to online/register the node > + */ > +int try_online_node(int nid) > +{ > + int ret; > + > + mem_hotplug_begin(); > + ret = __try_online_node (nid, 0, true); > mem_hotplug_done(); > return ret; > } > @@ -1099,8 +1116,6 @@ static int online_memory_block(struct memory_block *mem, void *arg) > int __ref add_memory_resource(int nid, struct resource *res, bool online) > { > u64 start, size; > - pg_data_t *pgdat = NULL; > - bool new_pgdat; > bool new_node; > int ret; > > @@ -1111,11 +1126,6 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > if (ret) > return ret; > > - { /* Stupid hack to suppress address-never-null warning */ > - void *p = NODE_DATA(nid); > - new_pgdat = !p; > - } > - > mem_hotplug_begin(); > > /* > @@ -1126,17 +1136,14 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > */ > memblock_add_node(start, size, nid); > > - new_node = !node_online(nid); > - if (new_node) { > - pgdat = hotadd_new_pgdat(nid, start); > - ret = -ENOMEM; > - if (!pgdat) > - goto error; > - } > + ret = __try_online_node (nid, start, false); space before ( > + new_node = !!(ret > 0); > + if (ret < 0) > + goto error; > + > > /* call arch's memory hotadd */ > ret = arch_add_memory(nid, start, size, NULL, true); > - > if (ret < 0) > goto error; > > @@ -1180,8 +1187,8 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > > error: > /* rollback pgdat allocation and others */ > - if (new_pgdat && pgdat) > - rollback_node_hotadd(nid, pgdat); > + if (new_node) > + rollback_node_hotadd(nid); > memblock_remove(start, size); > > out:
On Fri, 1 Jun 2018 14:53:18 +0200 osalvador@techadventures.net wrote: > From: Oscar Salvador <osalvador@suse.de> > > add_memory_resource() contains code to allocate a new node in case > it is necessary. > Since try_online_node() also hast some code for this purpose, > let us make use of that and remove duplicate code. > > This introduces __try_online_node(), which is called by add_memory_resource() > and try_online_node(). > __try_online_node() has two new parameters, start_addr of the node, > and if the node should be onlined and registered right away. > This is always wanted if we are calling from do_cpu_up(), but not > when we are calling from memhotplug code. > Nothing changes from the point of view of the users of try_online_node(), > since try_online_node passes start_addr=0 and online_node=true to > __try_online_node(). > > ... > > @@ -1126,17 +1136,14 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) > */ > memblock_add_node(start, size, nid); > > - new_node = !node_online(nid); > - if (new_node) { > - pgdat = hotadd_new_pgdat(nid, start); > - ret = -ENOMEM; > - if (!pgdat) > - goto error; > - } > + ret = __try_online_node (nid, start, false); > + new_node = !!(ret > 0); I don't think __try_online_node() will ever return a value greater than zero. I assume what was meant was new_node = !!(ret >= 0); which may as well be new_node = (ret >= 0); since both sides have bool type. The fact that testing didn't detect this is worrisome.... > + if (ret < 0) > + goto error; > + > > /* call arch's memory hotadd */ > ret = arch_add_memory(nid, start, size, NULL, true); > - > if (ret < 0) > goto error; > > > ... >
> I don't think __try_online_node() will ever return a value greater than > zero. I assume what was meant was Hi Andrew and Oscar, Actually, the new __try_online_node() returns: 1 -> a new node was allocated 0 -> node is already online -error -> an error encountered. The function simply missing the return comment at the beginning. Oscar, please check it via ./scripts/checkpatch.pl Add comment explaining the return values. And change: ret = __try_online_node (nid, start, false); new_node = !!(ret > 0); if (ret < 0) goto error; To: ret = __try_online_node (nid, start, false); if (ret < 0) goto error; new_node = ret; Other than that the patch looks good to me, it simplifies the code. So, if the above is addressed: Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Thank you, Pavel > > new_node = !!(ret >= 0); > > which may as well be > > new_node = (ret >= 0); > > since both sides have bool type. > > The fact that testing didn't detect this is worrisome.... > > > + if (ret < 0) > > + goto error; > > + > > > > /* call arch's memory hotadd */ > > ret = arch_add_memory(nid, start, size, NULL, true); > > - > > if (ret < 0) > > goto error; > > > > > > ... > > >
On Wed, Jun 20, 2018 at 09:41:35PM -0400, Pavel Tatashin wrote: > > I don't think __try_online_node() will ever return a value greater than > > zero. I assume what was meant was > > Hi Andrew and Oscar, > > Actually, the new __try_online_node() returns: > 1 -> a new node was allocated > 0 -> node is already online > -error -> an error encountered. > > The function simply missing the return comment at the beginning. > > Oscar, please check it via ./scripts/checkpatch.pl > > Add comment explaining the return values. > > And change: > ret = __try_online_node (nid, start, false); > new_node = !!(ret > 0); > if (ret < 0) > goto error; > To: > ret = __try_online_node (nid, start, false); > if (ret < 0) > goto error; > new_node = ret; > > Other than that the patch looks good to me, it simplifies the code. > So, if the above is addressed: > > Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> Hi Pavel, I'll do so, thanks! > > Thank you, > Pavel > > > > > new_node = !!(ret >= 0); > > > > which may as well be > > > > new_node = (ret >= 0); > > > > since both sides have bool type. > > > > The fact that testing didn't detect this is worrisome.... > > > > > + if (ret < 0) > > > + goto error; > > > + > > > > > > /* call arch's memory hotadd */ > > > ret = arch_add_memory(nid, start, size, NULL, true); > > > - > > > if (ret < 0) > > > goto error; > > > > > > > > > ... > > > > > >
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7deb49f69e27..29a5fc89bdb1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1034,8 +1034,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) return pgdat; } -static void rollback_node_hotadd(int nid, pg_data_t *pgdat) +static void rollback_node_hotadd(int nid) { + pg_data_t *pgdat = NODE_DATA(nid); + arch_refresh_nodedata(nid, NULL); free_percpu(pgdat->per_cpu_nodestats); arch_free_nodedata(pgdat); @@ -1046,28 +1048,43 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) /** * try_online_node - online a node if offlined * @nid: the node ID - * + * @start: start addr of the node + * @set_node_online: Whether we want to online the node * called by cpu_up() to online a node without onlined memory. */ -int try_online_node(int nid) +static int __try_online_node(int nid, u64 start, bool set_node_online) { - pg_data_t *pgdat; - int ret; + pg_data_t *pgdat; + int ret = 1; if (node_online(nid)) return 0; - mem_hotplug_begin(); - pgdat = hotadd_new_pgdat(nid, 0); + pgdat = hotadd_new_pgdat(nid, start); if (!pgdat) { pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; goto out; } - node_set_online(nid); - ret = register_one_node(nid); - BUG_ON(ret); + + if (set_node_online) { + node_set_online(nid); + ret = register_one_node(nid); + BUG_ON(ret); + } out: + return ret; +} + +/* + * Users of this function always want to online/register the node + */ +int try_online_node(int nid) +{ + int ret; + + mem_hotplug_begin(); + ret = __try_online_node (nid, 0, true); mem_hotplug_done(); return ret; } @@ -1099,8 +1116,6 @@ static int online_memory_block(struct memory_block *mem, void *arg) int __ref add_memory_resource(int nid, struct resource *res, bool online) { u64 start, size; - pg_data_t *pgdat = NULL; - bool new_pgdat; bool new_node; int ret; @@ -1111,11 +1126,6 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) if (ret) return ret; - { /* Stupid hack to suppress address-never-null warning */ - void *p = NODE_DATA(nid); - new_pgdat = !p; - } - mem_hotplug_begin(); /* @@ -1126,17 +1136,14 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) */ memblock_add_node(start, size, nid); - new_node = !node_online(nid); - if (new_node) { - pgdat = hotadd_new_pgdat(nid, start); - ret = -ENOMEM; - if (!pgdat) - goto error; - } + ret = __try_online_node (nid, start, false); + new_node = !!(ret > 0); + if (ret < 0) + goto error; + /* call arch's memory hotadd */ ret = arch_add_memory(nid, start, size, NULL, true); - if (ret < 0) goto error; @@ -1180,8 +1187,8 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) error: /* rollback pgdat allocation and others */ - if (new_pgdat && pgdat) - rollback_node_hotadd(nid, pgdat); + if (new_node) + rollback_node_hotadd(nid); memblock_remove(start, size); out: