From: Jeff Moyer <jmoyer@redhat.com> To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: linux-nvdimm@lists.01.org Subject: Re: [RFC PATCH] libnvdimm: Update the meaning for persistence_domain values Date: Wed, 15 Jan 2020 11:55:30 -0500 Message-ID: <x49o8v4oe0t.fsf@segfault.boston.devel.redhat.com> (raw) In-Reply-To: <20200108064905.170394-1-aneesh.kumar@linux.ibm.com> (Aneesh Kumar K. V.'s message of "Wed, 8 Jan 2020 12:19:05 +0530") "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > Currently, kernel shows the below values > "persistence_domain":"cpu_cache" > "persistence_domain":"memory_controller" > "persistence_domain":"unknown" > > This patch updates the meaning of these values such that > > "cpu_cache" indicates no extra instructions is needed to ensure the persistence > of data in the pmem media on power failure. > > "memory_controller" indicates platform provided instructions need to be issued > as per documented sequence to make sure data flushed is guaranteed to be on pmem > media in case of system power loss. > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > --- > arch/powerpc/platforms/pseries/papr_scm.c | 7 ++++++- > include/linux/libnvdimm.h | 6 +++--- > 2 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c > index c2ef320ba1bf..26a5ef263758 100644 > --- a/arch/powerpc/platforms/pseries/papr_scm.c > +++ b/arch/powerpc/platforms/pseries/papr_scm.c > @@ -360,8 +360,13 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p) > > if (p->is_volatile) > p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc); > - else > + else { > + /* > + * We need to flush things correctly to guarantee persistance > + */ > + set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags); > p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc); > + } > if (!p->region) { > dev_err(dev, "Error registering region %pR from %pOF\n", > ndr_desc.res, p->dn); Would you also update of_pmem to indicate the persistence domain, please? > diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h > index f2a33f2e3ba8..9126737377e1 100644 > --- a/include/linux/libnvdimm.h > +++ b/include/linux/libnvdimm.h > @@ -52,9 +52,9 @@ enum { > */ > ND_REGION_PERSIST_CACHE = 1, > /* > - * Platform provides mechanisms to automatically flush outstanding > - * write data from memory controler to pmem on system power loss. > - * (ADR) > + * Platform provides instructions to flush data such that on completion > + * of the instructions, data flushed is guaranteed to be on pmem even > + * in case of a system power loss. I find the prior description easier to understand. -Jeff _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply index Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-08 6:49 Aneesh Kumar K.V 2020-01-15 16:55 ` Jeff Moyer [this message] 2020-01-15 17:27 ` Aneesh Kumar K.V 2020-01-15 17:31 ` Aneesh Kumar K.V 2020-01-15 17:42 ` Jeff Moyer 2020-01-15 19:44 ` Dan Williams 2020-01-15 17:35 ` Jeff Moyer 2020-01-15 17:55 ` Aneesh Kumar K.V 2020-01-15 19:48 ` Dan Williams 2020-01-16 6:24 ` Aneesh Kumar K.V
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=x49o8v4oe0t.fsf@segfault.boston.devel.redhat.com \ --to=jmoyer@redhat.com \ --cc=aneesh.kumar@linux.ibm.com \ --cc=linux-nvdimm@lists.01.org \ /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: link
Linux-NVDIMM Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-nvdimm/0 linux-nvdimm/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-nvdimm linux-nvdimm/ https://lore.kernel.org/linux-nvdimm \ linux-nvdimm@lists.01.org public-inbox-index linux-nvdimm Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.01.lists.linux-nvdimm AGPL code for this site: git clone https://public-inbox.org/public-inbox.git