On Fri, 2021-09-10 at 17:11 +0200, Greg Kroah-Hartman wrote: > On Fri, Sep 10, 2021 at 06:02:59PM +0300, Jarkko Sakkinen wrote: > > On Fri, 2021-09-10 at 16:05 +0200, Greg Kroah-Hartman wrote: > > > On Fri, Sep 10, 2021 at 04:17:44PM +0300, Jarkko Sakkinen wrote: > > > > On Fri, 2021-09-10 at 08:51 +0200, Greg Kroah-Hartman wrote: > > > > > On Fri, Sep 10, 2021 at 03:17:24AM +0300, Jarkko Sakkinen wrote: > > > > > > The amount of SGX memory on the system is determined by the BIOS and it > > > > > > varies wildly between systems. It can be from dozens of MB's on desktops > > > > > > or VM's, up to many GB's on servers. Just like for regular memory, it is > > > > > > sometimes useful to know the amount of usable SGX memory in the system. > > > > > > > > > > > > Add SGX_MemTotal field to /sys/devices/system/node/node*/meminfo, > > > > > > showing the total SGX memory in each NUMA node. The total memory for > > > > > > each NUMA node is calculated by adding the sizes of contained EPC > > > > > > sections together. > > > > > > > > > > > > Introduce arch_node_read_meminfo(), which can optionally be rewritten by > > > > > > the arch code, and rewrite it for x86 so it prints SGX_MemTotal. > > > > > > > > > > > > Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> > > > > > > --- > > > > > > v4: > > > > > > * A new patch. > > > > > > arch/x86/kernel/cpu/sgx/main.c | 14 ++++++++++++++ > > > > > > arch/x86/kernel/cpu/sgx/sgx.h | 6 ++++++ > > > > > > drivers/base/node.c | 10 +++++++++- > > > > > > 3 files changed, 29 insertions(+), 1 deletion(-) > > > > > > > > > > Where is the Documentation/ABI/ update for this new sysfs file? > > > > > > > > It's has been existed for a long time, e.g. > > > > > > > > cat /sys/devices/system/node/node0/meminfo > > > > Node 0 MemTotal: 32706792 kB > > > > Node 0 MemFree: 5382988 kB > > > > Node 0 MemUsed: 27323804 kB > > > > Node 0 SwapCached: 8 kB > > > > Node 0 Active: 3640612 kB > > > > Node 0 Inactive: 21757684 kB > > > > Node 0 Active(anon): 2833772 kB > > > > Node 0 Inactive(anon): 14392 kB > > > > Node 0 Active(file): 806840 kB > > > > Node 0 Inactive(file): 21743292 kB > > > > Node 0 Unevictable: 80640 kB > > > > Node 0 Mlocked: 80640 kB > > > > Node 0 Dirty: 36 kB > > > > Node 0 Writeback: 0 kB > > > > Node 0 FilePages: 22833124 kB > > > > Node 0 Mapped: 1112832 kB > > > > Node 0 AnonPages: 2645812 kB > > > > Node 0 Shmem: 282984 kB > > > > Node 0 KernelStack: 18544 kB > > > > Node 0 PageTables: 46704 kB > > > > Node 0 NFS_Unstable: 0 kB > > > > Node 0 Bounce: 0 kB > > > > Node 0 WritebackTmp: 0 kB > > > > Node 0 KReclaimable: 1311812 kB > > > > Node 0 Slab: 1542220 kB > > > > Node 0 SReclaimable: 1311812 kB > > > > Node 0 SUnreclaim: 230408 kB > > > > Node 0 AnonHugePages: 0 kB > > > > Node 0 ShmemHugePages: 0 kB > > > > Node 0 ShmemPmdMapped: 0 kB > > > > Node 0 FileHugePages: 0 kB > > > > Node 0 FilePmdMapped: 0 kB > > > > Node 0 HugePages_Total: 0 > > > > Node 0 HugePages_Free: 0 > > > > Node 0 HugePages_Surp: 0 > > > > This was something also spinned my head a bit, i.e. why hugepages fields > > are not aligned correctly. > > > > > > This file is undocumented but the fields seem to reflect what is in > > > > /proc/meminfo, so I added additional patch for documentation: > > > > > > > > https://lore.kernel.org/linux-sgx/20210910001726.811497-3-jarkko@xxxxxxxxxx/ > > > > > > > > I have no idea why things are how they are. I'm just merely trying to follow > > > > the existing patterns. I'm also fully aware of the defacto sysfs pattern, i.e. > > > > one value per file. > > > > > > Then please do not add anything else to this nightmare of a mess. > > > > There is already /sys/devices/system/node/node0/hugepages/. > > > > It has alike data to the contents of meminfo: > > > > /sys/devices/system/node/node0/hugepages/hugepages-2048kB: > > surplus_hugepages > > nr_hugepages > > free_hugepages > > > > /sys/devices/system/node/node0/hugepages/hugepages-1048576kB: > > surplus_hugepages > > nr_hugepages > > free_hugepages > > > > [I'm wondering tho, how the fields in meminfo are supposed to be interpreted, > > given that there are two types of huge pages, but let's just ignore that > > for the moment.] > > > > Following this pattern, I'd perhaps go and create (and document): > > > > /sys/devices/system/node/node0/sgx/memory_size > > > > which would have the size in bytes. > > If it is one-value-per-file, that's fine with me. And if it's represented like this to user space, I think that /proc/meminfo change is unnecessary: it's less involving (e.g. in scripting) to parse these files in a loop and sum then, than grep the appropriate line from /proc/meminfo. Would no make much common sense to maintain it. For me the only open here is: would it make more sense to add x86 subdirectory to each node? With this approach the path would be something like: * /sys/devices/system/node/node0/x86/sgx_memory_size I guess huge pages is different in the sense that it's not just one arch thing, whereas SGX is directly arch related, so I think that this would be a more civilized way to deal with SGX. This way things won't bloat, if or when something else ought to need a NUMA node specific attribute. > thanks, > > greg k-h /Jarkko
