From: Michael Ellerman <mpe@ellerman.id.au>
To: Scott Cheloha <cheloha@linux.ibm.com>, linuxppc-dev@ozlabs.org
Cc: Nathan Lynch <nathanl@linux.ibm.com>,
Michal Suchanek <msuchanek@suse.de>,
David Hildenbrand <david@redhat.com>,
Rick Lindsley <ricklind@linux.vnet.ibm.com>,
Laurent Dufour <ldufour@linux.vnet.ibm.com>
Subject: Re: [PATCH v1] pseries/hotplug-memory: hot-add: skip redundant LMB lookup
Date: Fri, 11 Sep 2020 23:15:09 +1000 [thread overview]
Message-ID: <87sgboqwte.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <20200910175637.2865160-1-cheloha@linux.ibm.com>
Hi Scott,
Scott Cheloha <cheloha@linux.ibm.com> writes:
> During memory hot-add, dlpar_add_lmb() calls memory_add_physaddr_to_nid()
> to determine which node id (nid) to use when later calling __add_memory().
>
...
>
> Consider an LPAR with 126976 LMBs. In one test, hot-adding 126000
Nice little machine you got there :P
> LMBs on an upatched kernel took ~3.5 hours while a patched kernel
> completed the same operation in ~2 hours:
...
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 0ea976d1cac4..9cd572440175 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -595,6 +595,8 @@ static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
> }
> #endif /* CONFIG_MEMORY_HOTREMOVE */
>
> +extern int of_drconf_to_nid_single(struct drmem_lmb *);
> +
This needs to go in a header.
It should probably go in arch/powerpc/include/asm/topology.h
cheers
> static int dlpar_add_lmb(struct drmem_lmb *lmb)
> {
> unsigned long block_sz;
> @@ -611,8 +613,10 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>
> block_sz = memory_block_size_bytes();
>
> - /* Find the node id for this address. */
> - nid = memory_add_physaddr_to_nid(lmb->base_addr);
> + /* Find the node id for this address. Fake one if necessary. */
> + nid = of_drconf_to_nid_single(lmb);
> + if (nid < 0 || !node_possible(nid))
> + nid = first_online_node;
>
> /* Add the memory */
> rc = __add_memory(nid, lmb->base_addr, block_sz);
> --
> 2.24.1
prev parent reply other threads:[~2020-09-11 13:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 17:56 [PATCH v1] pseries/hotplug-memory: hot-add: skip redundant LMB lookup Scott Cheloha
2020-09-11 5:18 ` kernel test robot
2020-09-11 10:28 ` kernel test robot
2020-09-11 13:15 ` Michael Ellerman [this message]
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