From: Davidlohr Bueso <dave@stgolabs.net> To: Andrew Morton <akpm@linux-foundation.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, "Kirill A. Shutemov" <kirill@shutemov.name>, David Rientjes <rientjes@google.com>, Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3] mm/thp: Allocate transparent hugepages on local node Date: Fri, 16 Jan 2015 23:15:59 -0800 [thread overview] Message-ID: <1421478959.4903.1.camel@stgolabs.net> (raw) In-Reply-To: <20150116160204.544e2bcf9627f5a4043ebf8d@linux-foundation.org> On Fri, 2015-01-16 at 16:02 -0800, Andrew Morton wrote: > On Fri, 16 Jan 2015 12:56:36 +0530 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> wrote: > > > This make sure that we try to allocate hugepages from local node if > > allowed by mempolicy. If we can't, we fallback to small page allocation > > based on mempolicy. This is based on the observation that allocating pages > > on local node is more beneficial than allocating hugepages on remote node. > > The changelog is a bit incomplete. It doesn't describe the current > behaviour, nor what is wrong with it. What are the before-and-after > effects of this change? > > And what might be the user-visible effects? I'd be interested in any performance data. I'll run this by a 4 node box next week. > > > --- a/mm/mempolicy.c > > +++ b/mm/mempolicy.c > > @@ -2030,6 +2030,46 @@ retry_cpuset: > > return page; > > } > > > > +struct page *alloc_hugepage_vma(gfp_t gfp, struct vm_area_struct *vma, > > + unsigned long addr, int order) > > alloc_pages_vma() is nicely documented. alloc_hugepage_vma() is not > documented at all. This makes it a bit had for readers to work out the > difference! > > Is it possible to scrunch them both into the same function? Probably > too messy? > > > +{ > > + struct page *page; > > + nodemask_t *nmask; > > + struct mempolicy *pol; > > + int node = numa_node_id(); > > + unsigned int cpuset_mems_cookie; > > + > > +retry_cpuset: > > + pol = get_vma_policy(vma, addr); > > + cpuset_mems_cookie = read_mems_allowed_begin(); > > + > > + if (pol->mode != MPOL_INTERLEAVE) { > > + /* > > + * For interleave policy, we don't worry about > > + * current node. Otherwise if current node is > > + * in nodemask, try to allocate hugepage from > > + * current node. Don't fall back to other nodes > > + * for THP. > > + */ > > This code isn't "interleave policy". It's everything *but* interleave > policy. Comment makes no sense! May I add that, while a nit, this indentation is quite ugly: > > > + nmask = policy_nodemask(gfp, pol); > > + if (!nmask || node_isset(node, *nmask)) { > > + mpol_cond_put(pol); > > + page = alloc_pages_exact_node(node, gfp, order); > > + if (unlikely(!page && > > + read_mems_allowed_retry(cpuset_mems_cookie))) > > + goto retry_cpuset; > > + return page; > > + } > > + } Improving it makes the code visually easier on the eye. So this should be considered if another re-spin of the patch is to be done anyway. Just jump to the mpol refcounting and be done when 'pol->mode == MPOL_INTERLEAVE'. Thanks, Davidlohr
WARNING: multiple messages have this Message-ID (diff)
From: Davidlohr Bueso <dave@stgolabs.net> To: Andrew Morton <akpm@linux-foundation.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, "Kirill A. Shutemov" <kirill@shutemov.name>, David Rientjes <rientjes@google.com>, Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3] mm/thp: Allocate transparent hugepages on local node Date: Fri, 16 Jan 2015 23:15:59 -0800 [thread overview] Message-ID: <1421478959.4903.1.camel@stgolabs.net> (raw) In-Reply-To: <20150116160204.544e2bcf9627f5a4043ebf8d@linux-foundation.org> On Fri, 2015-01-16 at 16:02 -0800, Andrew Morton wrote: > On Fri, 16 Jan 2015 12:56:36 +0530 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> wrote: > > > This make sure that we try to allocate hugepages from local node if > > allowed by mempolicy. If we can't, we fallback to small page allocation > > based on mempolicy. This is based on the observation that allocating pages > > on local node is more beneficial than allocating hugepages on remote node. > > The changelog is a bit incomplete. It doesn't describe the current > behaviour, nor what is wrong with it. What are the before-and-after > effects of this change? > > And what might be the user-visible effects? I'd be interested in any performance data. I'll run this by a 4 node box next week. > > > --- a/mm/mempolicy.c > > +++ b/mm/mempolicy.c > > @@ -2030,6 +2030,46 @@ retry_cpuset: > > return page; > > } > > > > +struct page *alloc_hugepage_vma(gfp_t gfp, struct vm_area_struct *vma, > > + unsigned long addr, int order) > > alloc_pages_vma() is nicely documented. alloc_hugepage_vma() is not > documented at all. This makes it a bit had for readers to work out the > difference! > > Is it possible to scrunch them both into the same function? Probably > too messy? > > > +{ > > + struct page *page; > > + nodemask_t *nmask; > > + struct mempolicy *pol; > > + int node = numa_node_id(); > > + unsigned int cpuset_mems_cookie; > > + > > +retry_cpuset: > > + pol = get_vma_policy(vma, addr); > > + cpuset_mems_cookie = read_mems_allowed_begin(); > > + > > + if (pol->mode != MPOL_INTERLEAVE) { > > + /* > > + * For interleave policy, we don't worry about > > + * current node. Otherwise if current node is > > + * in nodemask, try to allocate hugepage from > > + * current node. Don't fall back to other nodes > > + * for THP. > > + */ > > This code isn't "interleave policy". It's everything *but* interleave > policy. Comment makes no sense! May I add that, while a nit, this indentation is quite ugly: > > > + nmask = policy_nodemask(gfp, pol); > > + if (!nmask || node_isset(node, *nmask)) { > > + mpol_cond_put(pol); > > + page = alloc_pages_exact_node(node, gfp, order); > > + if (unlikely(!page && > > + read_mems_allowed_retry(cpuset_mems_cookie))) > > + goto retry_cpuset; > > + return page; > > + } > > + } Improving it makes the code visually easier on the eye. So this should be considered if another re-spin of the patch is to be done anyway. Just jump to the mpol refcounting and be done when 'pol->mode == MPOL_INTERLEAVE'. Thanks, Davidlohr -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-01-17 7:16 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-01-16 7:26 [PATCH V3] mm/thp: Allocate transparent hugepages on local node Aneesh Kumar K.V 2015-01-16 7:26 ` Aneesh Kumar K.V 2015-01-16 12:27 ` Kirill A. Shutemov 2015-01-16 12:27 ` Kirill A. Shutemov 2015-01-16 20:01 ` Vlastimil Babka 2015-01-16 20:01 ` Vlastimil Babka 2015-01-17 0:02 ` Andrew Morton 2015-01-17 0:02 ` Andrew Morton 2015-01-17 7:15 ` Davidlohr Bueso [this message] 2015-01-17 7:15 ` Davidlohr Bueso 2015-01-18 15:50 ` Aneesh Kumar K.V 2015-01-18 15:50 ` Aneesh Kumar K.V 2015-01-18 15:48 ` Aneesh Kumar K.V 2015-01-18 15:48 ` Aneesh Kumar K.V 2015-01-19 16:27 ` Vlastimil Babka 2015-01-19 16:27 ` Vlastimil Babka 2015-01-20 5:52 ` Aneesh Kumar K.V 2015-01-20 5:52 ` Aneesh Kumar K.V 2015-01-20 9:08 ` Vlastimil Babka 2015-01-20 9:08 ` Vlastimil Babka 2015-01-21 11:28 ` Vlastimil Babka 2015-01-21 11:28 ` Vlastimil Babka
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1421478959.4903.1.camel@stgolabs.net \ --to=dave@stgolabs.net \ --cc=akpm@linux-foundation.org \ --cc=aneesh.kumar@linux.vnet.ibm.com \ --cc=kirill@shutemov.name \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=rientjes@google.com \ --cc=vbabka@suse.cz \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.