From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id E54F621161235 for ; Mon, 1 Oct 2018 14:44:12 -0700 (PDT) Subject: Re: [PATCH v2] libnvdimm, dimm: Maximize label transfer size References: <153842839852.2679462.16816747305002065908.stgit@dwillia2-desk3.amr.corp.intel.com> From: Alexander Duyck Message-ID: <71e2a4b6-68d9-d90d-b927-90840d8c6ee1@linux.intel.com> Date: Mon, 1 Oct 2018 14:44:11 -0700 MIME-Version: 1.0 In-Reply-To: <153842839852.2679462.16816747305002065908.stgit@dwillia2-desk3.amr.corp.intel.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dan Williams , linux-nvdimm@lists.01.org Cc: linux-kernel@vger.kernel.org List-ID: On 10/1/2018 2:14 PM, Dan Williams wrote: > Use kvzalloc() to bypass the arbitrary PAGE_SIZE limit of label transfer > operations. Given the expense of calling into firmware, maximize the > amount of label data we transfer per call to be up to the total label > space if allowed by the firmware, or 256K whichever is smaller. > > Cc: Alexander Duyck > Signed-off-by: Dan Williams > --- > Changes in v2: > * clamp the max allocation size at 256K in case large label areas with > unlimited transfer sizes appear in the future. > > drivers/nvdimm/dimm_devs.c | 14 ++++++++------ > tools/testing/nvdimm/test/nfit.c | 2 +- > 2 files changed, 9 insertions(+), 7 deletions(-) > > diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c > index 863cabc35215..3616e2e47788 100644 > --- a/drivers/nvdimm/dimm_devs.c > +++ b/drivers/nvdimm/dimm_devs.c > @@ -111,8 +111,9 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd) > if (!ndd->data) > return -ENOMEM; > > - max_cmd_size = min_t(u32, PAGE_SIZE, ndd->nsarea.max_xfer); > - cmd = kzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL); > + max_cmd_size = min_t(u32, ndd->nsarea.config_size, SZ_256K); > + max_cmd_size = min_t(u32, max_cmd_size, ndd->nsarea.max_xfer); > + cmd = kvzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL); > if (!cmd) > return -ENOMEM; > So I wouldn't use 256K as the limit, maybe 256K minus the sizeof(*cmd). Otherwise you are still allocating additional memory to take care of that little trailing bit that is being added. > @@ -134,7 +135,7 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd) > memcpy(ndd->data + offset, cmd->out_buf, cmd->in_length); > } > dev_dbg(ndd->dev, "len: %zu rc: %d\n", offset, rc); > - kfree(cmd); > + kvfree(cmd); > > return rc; > } > @@ -157,9 +158,10 @@ int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset, > if (offset + len > ndd->nsarea.config_size) > return -ENXIO; > > - max_cmd_size = min_t(u32, PAGE_SIZE, len); > + max_cmd_size = min_t(u32, ndd->nsarea.config_size, SZ_256K); > max_cmd_size = min_t(u32, max_cmd_size, ndd->nsarea.max_xfer); > - cmd = kzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL); > + max_cmd_size = min_t(u32, max_cmd_size, len); > + cmd = kvzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL); > if (!cmd) > return -ENOMEM; > For the set operation I am not sure you have any code that is going to be updating things multiple labels at a time. From what I can tell the largest set call you ever make is probably for a namespace index and odds are that will only ever be 256 or 512 bytes. Also the limitations here could probably use some additional clean-up. For example you have a check for offset + len > config_size above this min_t calls. As such it should be impossible for length to ever be greater than config_size so you shouldn't need to test for the min of both and could just use the min of len versus the max_xfer. > @@ -183,7 +185,7 @@ int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset, > break; > } > } > - kfree(cmd); > + kvfree(cmd); > > return rc; > } > diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c > index cffc2c5a778d..caa58d8533f5 100644 > --- a/tools/testing/nvdimm/test/nfit.c > +++ b/tools/testing/nvdimm/test/nfit.c > @@ -448,7 +448,7 @@ static int nfit_test_cmd_get_config_size(struct nd_cmd_get_config_size *nd_cmd, > > nd_cmd->status = 0; > nd_cmd->config_size = LABEL_SIZE; > - nd_cmd->max_xfer = SZ_4K; > + nd_cmd->max_xfer = LABEL_SIZE; > > return 0; > } > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm