From: Dan Williams <dan.j.williams@intel.com>
To: <ira.weiny@intel.com>, Dave Jiang <dave.jiang@intel.com>,
Fan Ni <fan.ni@samsung.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
"Navneet Singh" <navneet.singh@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Davidlohr Bueso <dave@stgolabs.net>,
Alison Schofield <alison.schofield@intel.com>,
"Vishal Verma" <vishal.l.verma@intel.com>,
Ira Weiny <ira.weiny@intel.com>, <linux-btrfs@vger.kernel.org>,
<linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 18/26] cxl/mem: Handle DCD add & release capacity events.
Date: Mon, 6 May 2024 22:04:23 -0700 [thread overview]
Message-ID: <6639b657da437_2f63a29410@dwillia2-mobl3.amr.corp.intel.com.notmuch> (raw)
In-Reply-To: <20240324-dcd-type2-upstream-v1-18-b7b00d623625@intel.com>
ira.weiny@ wrote:
> From: Navneet Singh <navneet.singh@intel.com>
>
> A dynamic capacity devices (DCD) send events to signal the host about
> changes in the availability of Dynamic Capacity (DC) memory. These
> events contain extents, the addition or removal of which may occur at
> any time.
>
> Adding memory is straight forward. If no region exists the extent is
> rejected. If a region does exist, a region extent is formed and
> surfaced.
>
> Removing memory requires checking if the memory is currently in use.
> Memory use tracking is added in a subsequent patch so here the memory is
> never in use and the removal occurs immediately.
>
> Most often extents will be offered to and accepted by the host in well
> defined chunks. However, part of an extent may be requested for
> release. Simplify extent tracking by signaling removal of any extent
> which overlaps the requested release range.
>
> Force removal is intended as a mechanism between the FM and the device
> and intended only when the host is unresponsive or otherwise broken.
> Purposely ignore force removal events.
>
> Process DCD extents.
>
> Recall that all devices of an interleave set must offer a corresponding
> extent for the region extent to be realized. This patch limits
> interleave to 1. Thus the 1:1 mapping between device extent and DAX
> region extent allows immediate surfacing.
>
> Signed-off-by: Navneet Singh <navneet.singh@intel.com>
> Co-developed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
>
> ---
> Changes for v1
> [iweiny: remove all xarrays]
> [iweiny: entirely new architecture]
> ---
> drivers/cxl/core/extent.c | 4 ++
> drivers/cxl/core/mbox.c | 142 +++++++++++++++++++++++++++++++++++++++++++---
> drivers/cxl/core/region.c | 139 ++++++++++++++++++++++++++++++++++++++++-----
> drivers/cxl/cxl.h | 34 +++++++++++
> drivers/cxl/cxlmem.h | 21 +++----
> drivers/cxl/mem.c | 45 +++++++++++++++
> drivers/dax/cxl.c | 22 +++++++
> include/linux/cxl-event.h | 31 ++++++++++
> 8 files changed, 405 insertions(+), 33 deletions(-)
>
[..]
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 7635ff109578..a07d95136f0d 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
[..]
> @@ -1502,18 +1552,7 @@ int cxl_ed_add_one_extent(struct cxl_endpoint_decoder *cxled,
> dev_dbg(dev, "Adding DC extent DPA %#llx - %#llx\n",
> ext_dpa_range.start, ext_dpa_range.end);
>
> - /*
> - * Without interleave...
> - * HPA offset == DPA offset
> - * ... but do the math anyway
> - */
> - dpa_offset = ext_dpa_range.start - cxled->dpa_res->start;
> - hpa = cxled->cxld.hpa_range.start + dpa_offset;
> -
> - ext_hpa_range = (struct range) {
> - .start = hpa - cxlr->cxlr_dax->hpa_range.start,
> - .end = ext_hpa_range.start + range_len(&ext_dpa_range) - 1,
> - };
Please don't refactor code that just got added in the same series. Upon
seeing that this wants a common helper in this patch, go back to the
original patch and put it in a helper from the beginning.
[..]
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 5379ad7f5852..156d7c9a8de5 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
[..]
> @@ -891,10 +900,18 @@ bool is_cxl_region(struct device *dev);
>
> extern struct bus_type cxl_bus_type;
I skipped ahead here in the review since notification organization feels
wrong.
> +/* Driver Notifier Data */
> +struct cxl_drv_nd {
I never would have guessed that cxl_drv_nd meant cxl driver notifier
data, it might be able to be jettisoned.
> + enum dc_event event;
> + struct cxl_dc_extent *dc_extent;
> + struct region_extent *reg_ext;
> +};
> +
> struct cxl_driver {
> const char *name;
> int (*probe)(struct device *dev);
> void (*remove)(struct device *dev);
> + int (*notify)(struct device *dev, struct cxl_drv_nd *nd);
First, this feels an overly DCD specific mechanism to inflict on the core
generic 'struct cxl_driver'. Most 'struct cxl_driver' instances do not
need any 'notify' callback and 'struct cxl_drv_nd' makes this even less
relevant to the core 'struct cxl_driver' definition.
Second, it leads to 2 anonymous ->notify() callbacks wht too deep of a
stack. It feels as if the resulting code is being actively evasive.
Given that the event handling code already knows how to lookup a 'struct
cxl_region', as Alison demonstrated in her DPA->HPA series, it should be
straightforward to lookup a 'struct cxl_dax_region' without a notifying
the cxl_mem driver.
So my expectation is just enough DCD event parsing to determine when the
payload applies to given cxl_dax_region. Then define a:
struct cxl_dax_region_driver {
struct cxl_driver driver;
void (*notify)(struct cxl_dax_region *cxlr_dax, ...);
};
...to send the payload over for further processing. If a cxl_dax_region
device instance cannot be found, just drop the event record.
next prev parent reply other threads:[~2024-05-07 5:04 UTC|newest]
Thread overview: 160+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-24 23:18 [PATCH 00/26] DCD: Add support for Dynamic Capacity Devices (DCD) ira.weiny
2024-03-24 23:18 ` [PATCH 01/26] cxl/mbox: Flag " ira.weiny
2024-03-25 16:11 ` Jonathan Cameron
2024-03-25 22:16 ` fan
2024-03-25 22:56 ` Davidlohr Bueso
2024-04-02 22:26 ` Ira Weiny
2024-03-26 16:34 ` Dave Jiang
2024-04-02 22:30 ` Ira Weiny
2024-04-10 18:15 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 02/26] cxl/core: Separate region mode from decoder mode ira.weiny
2024-03-25 16:20 ` Jonathan Cameron
2024-04-02 23:24 ` Ira Weiny
2024-03-25 23:18 ` Davidlohr Bueso
2024-03-28 5:22 ` Ira Weiny
2024-03-28 20:09 ` Dave Jiang
2024-04-02 23:27 ` Ira Weiny
2024-04-24 17:58 ` Ira Weiny
2024-04-02 23:25 ` Ira Weiny
2024-04-10 18:49 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 03/26] cxl/mem: Read dynamic capacity configuration from the device ira.weiny
2024-03-25 17:40 ` Jonathan Cameron
2024-04-03 22:22 ` Ira Weiny
2024-03-25 23:36 ` fan
2024-04-03 22:41 ` Ira Weiny
2024-04-02 11:41 ` Jørgen Hansen
2024-04-05 18:09 ` Ira Weiny
2024-04-09 8:42 ` Jørgen Hansen
2024-04-09 2:00 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 04/26] cxl/region: Add dynamic capacity decoder and region modes ira.weiny
2024-03-25 17:42 ` Jonathan Cameron
2024-03-26 16:17 ` fan
2024-03-27 15:43 ` Dave Jiang
2024-04-05 18:19 ` Ira Weiny
2024-04-06 0:01 ` Dave Jiang
2024-05-14 2:40 ` Zhijian Li (Fujitsu)
2024-03-24 23:18 ` [PATCH 05/26] cxl/core: Simplify cxl_dpa_set_mode() Ira Weiny
2024-03-25 17:46 ` Jonathan Cameron
2024-03-25 21:38 ` Davidlohr Bueso
2024-03-26 16:25 ` fan
2024-03-26 17:46 ` Dave Jiang
2024-04-05 19:21 ` Ira Weiny
2024-04-06 0:02 ` Dave Jiang
2024-04-09 0:43 ` Alison Schofield
2024-05-03 19:09 ` Ira Weiny
2024-05-03 20:33 ` Alison Schofield
2024-05-04 1:19 ` Dan Williams
2024-05-06 4:06 ` Ira Weiny
2024-05-04 4:13 ` Dan Williams
2024-05-06 3:46 ` Ira Weiny
2024-03-24 23:18 ` [PATCH 06/26] cxl/port: Add Dynamic Capacity mode support to endpoint decoders ira.weiny
2024-03-26 16:35 ` fan
2024-04-05 19:50 ` Ira Weiny
2024-03-26 17:58 ` Dave Jiang
2024-04-05 20:34 ` Ira Weiny
2024-04-04 8:32 ` Jonathan Cameron
2024-04-05 20:56 ` Ira Weiny
2024-05-06 16:22 ` Dan Williams
2024-05-10 5:31 ` Ira Weiny
2024-04-10 20:33 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 07/26] cxl/port: Add dynamic capacity size " ira.weiny
2024-04-05 13:54 ` Jonathan Cameron
2024-05-03 17:09 ` Ira Weiny
2024-05-03 17:21 ` Dan Williams
2024-05-06 4:07 ` Ira Weiny
2024-04-10 22:50 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 08/26] cxl/mem: Expose device dynamic capacity capabilities ira.weiny
2024-03-25 23:40 ` Davidlohr Bueso
2024-03-26 18:30 ` fan
2024-04-04 8:44 ` Jonathan Cameron
2024-04-04 8:51 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 09/26] cxl/region: Add Dynamic Capacity CXL region support ira.weiny
2024-03-26 22:31 ` fan
2024-04-10 4:25 ` Ira Weiny
2024-03-27 17:27 ` Dave Jiang
2024-04-10 4:35 ` Ira Weiny
2024-04-04 10:26 ` Jonathan Cameron
2024-04-10 4:40 ` Ira Weiny
2024-03-24 23:18 ` [PATCH 10/26] cxl/events: Factor out event msgnum configuration Ira Weiny
2024-03-27 17:38 ` Dave Jiang
2024-04-04 15:07 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 11/26] cxl/pci: Delay event buffer allocation Ira Weiny
2024-03-25 22:26 ` Davidlohr Bueso
2024-03-27 17:38 ` Dave Jiang
2024-04-04 15:08 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 12/26] cxl/pci: Factor out interrupt policy check Ira Weiny
2024-03-27 17:41 ` Dave Jiang
2024-04-04 15:10 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 13/26] cxl/mem: Configure dynamic capacity interrupts ira.weiny
2024-03-26 23:12 ` fan
2024-04-10 4:48 ` Ira Weiny
2024-03-27 17:54 ` Dave Jiang
2024-04-10 5:26 ` Ira Weiny
2024-04-04 15:22 ` Jonathan Cameron
2024-04-10 5:34 ` Ira Weiny
2024-04-10 23:23 ` Alison Schofield
2024-05-06 16:56 ` Dan Williams
2024-03-24 23:18 ` [PATCH 14/26] cxl/region: Read existing extents on region creation ira.weiny
2024-03-26 23:27 ` fan
2024-04-10 5:46 ` Ira Weiny
2024-03-27 17:45 ` fan
2024-04-10 6:19 ` Ira Weiny
2024-03-27 18:31 ` Dave Jiang
2024-04-10 6:09 ` Ira Weiny
2024-04-02 13:57 ` Jørgen Hansen
2024-04-10 6:29 ` Ira Weiny
2024-04-04 16:04 ` Jonathan Cameron
2024-04-04 16:13 ` Jonathan Cameron
2024-04-10 17:44 ` Alison Schofield
2024-05-06 18:34 ` Dan Williams
2024-03-24 23:18 ` [PATCH 15/26] range: Add range_overlaps() Ira Weiny
2024-03-25 18:33 ` David Sterba
2024-03-25 21:24 ` Davidlohr Bueso
2024-03-26 12:51 ` Johannes Thumshirn
2024-03-27 17:36 ` fan
2024-03-28 20:09 ` Dave Jiang
2024-04-04 16:06 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 16/26] cxl/extent: Realize extent devices ira.weiny
2024-03-27 22:34 ` fan
2024-03-28 21:11 ` Dave Jiang
2024-04-24 19:57 ` Ira Weiny
2024-04-04 16:32 ` Jonathan Cameron
2024-04-30 3:23 ` Ira Weiny
2024-05-02 21:12 ` Dan Williams
2024-05-06 4:35 ` Ira Weiny
2024-04-11 0:09 ` Alison Schofield
2024-05-07 1:30 ` Dan Williams
2024-03-24 23:18 ` [PATCH 17/26] dax/region: Create extent resources on DAX region driver load ira.weiny
2024-04-04 16:36 ` Jonathan Cameron
2024-04-09 16:22 ` fan
2024-05-07 2:31 ` Dan Williams
2024-03-24 23:18 ` [PATCH 18/26] cxl/mem: Handle DCD add & release capacity events ira.weiny
2024-04-04 17:03 ` Jonathan Cameron
2024-05-07 5:04 ` Dan Williams [this message]
2024-03-24 23:18 ` [PATCH 19/26] dax/bus: Factor out dev dax resize logic Ira Weiny
2024-04-04 17:15 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 20/26] dax: Document dax dev range tuple Ira Weiny
2024-04-01 17:06 ` Dave Jiang
2024-04-04 17:19 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 21/26] dax/region: Prevent range mapping allocation on sparse regions Ira Weiny
2024-04-01 17:07 ` Dave Jiang
2024-04-10 23:02 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 22/26] dax/region: Support DAX device creation on sparse DAX regions Ira Weiny
2024-04-04 17:36 ` Jonathan Cameron
2024-03-24 23:18 ` [PATCH 23/26] cxl/mem: Trace Dynamic capacity Event Record ira.weiny
2024-04-01 17:56 ` Dave Jiang
2024-04-04 17:38 ` Jonathan Cameron
2024-04-10 17:03 ` Alison Schofield
2024-03-24 23:18 ` [PATCH 24/26] tools/testing/cxl: Make event logs dynamic Ira Weiny
2024-03-24 23:18 ` [PATCH 25/26] tools/testing/cxl: Add DC Regions to mock mem data Ira Weiny
2024-03-24 23:18 ` [PATCH 26/26] tools/testing/cxl: Add Dynamic Capacity events Ira Weiny
2024-03-25 19:24 ` [PATCH 00/26] DCD: Add support for Dynamic Capacity Devices (DCD) fan
2024-03-28 5:20 ` Ira Weiny
2024-04-03 20:39 ` Jonathan Cameron
2024-04-04 10:20 ` Jonathan Cameron
2024-04-04 17:49 ` Jonathan Cameron
2024-05-01 23:49 ` Ira Weiny
2024-05-03 9:20 ` Jonathan Cameron
2024-05-06 4:24 ` Ira Weiny
2024-05-08 14:43 ` Jonathan Cameron
2024-04-10 18:01 ` Alison Schofield
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