All the LMB from the same set of ibm,dynamic-memory-v2 property are
sharing the same NUMA node. Don't compute that node for each one.
Tested on a system with 1022 LMBs spread on 4 NUMA nodes, only 4 calls to
lmb_set_nid() have been made instead of 1022.
This should prevent some soft lockups when starting large guests
Signed-off-by: Laurent Dufour <[email protected]>
---
arch/powerpc/mm/drmem.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index b2eeea39684c..3819c523c65b 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -397,7 +397,7 @@ static void __init init_drmem_v1_lmbs(const __be32 *prop)
static void __init init_drmem_v2_lmbs(const __be32 *prop)
{
- struct drmem_lmb *lmb;
+ struct drmem_lmb *lmb, *first;
struct of_drconf_cell_v2 dr_cell;
const __be32 *p;
u32 i, j, lmb_sets;
@@ -422,10 +422,18 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
/* second pass, read in the LMB information */
lmb_index = 0;
p = prop;
+ first = NULL;
for (i = 0; i < lmb_sets; i++) {
read_drconf_v2_cell(&dr_cell, &p);
+ /*
+ * Fetch the NUMA node id for the fist set or if the
+ * associativity index is different from the previous set.
+ */
+ if (first && dr_cell.aa_index != first->aa_index)
+ first = NULL;
+
for (j = 0; j < dr_cell.seq_lmbs; j++) {
lmb = &drmem_info->lmbs[lmb_index++];
@@ -438,7 +446,16 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
lmb->aa_index = dr_cell.aa_index;
lmb->flags = dr_cell.flags;
- lmb_set_nid(lmb);
+ /*
+ * All the LMB in the set share the same NUMA
+ * associativity property. So read that node only once.
+ */
+ if (!first) {
+ lmb_set_nid(lmb);
+ first = lmb;
+ } else {
+ lmb->nid = first->nid;
+ }
}
}
}
--
2.28.0
Hi Laurent,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on powerpc/next]
[also build test ERROR on linux/master linus/master v5.8 next-20200804]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Laurent-Dufour/powerpc-drmem-Don-t-compute-the-NUMA-node-for-each-LMB/20200805-173213
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-mpc885_ads_defconfig (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
All errors (new ones prefixed by >>):
arch/powerpc/mm/drmem.c: In function 'init_drmem_v2_lmbs':
>> arch/powerpc/mm/drmem.c:457:8: error: 'struct drmem_lmb' has no member named 'nid'
457 | lmb->nid = first->nid;
| ^~
arch/powerpc/mm/drmem.c:457:21: error: 'struct drmem_lmb' has no member named 'nid'
457 | lmb->nid = first->nid;
| ^~
vim +457 arch/powerpc/mm/drmem.c
397
398 static void __init init_drmem_v2_lmbs(const __be32 *prop)
399 {
400 struct drmem_lmb *lmb, *first;
401 struct of_drconf_cell_v2 dr_cell;
402 const __be32 *p;
403 u32 i, j, lmb_sets;
404 int lmb_index;
405
406 lmb_sets = of_read_number(prop++, 1);
407 if (lmb_sets == 0)
408 return;
409
410 /* first pass, calculate the number of LMBs */
411 p = prop;
412 for (i = 0; i < lmb_sets; i++) {
413 read_drconf_v2_cell(&dr_cell, &p);
414 drmem_info->n_lmbs += dr_cell.seq_lmbs;
415 }
416
417 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
418 GFP_KERNEL);
419 if (!drmem_info->lmbs)
420 return;
421
422 /* second pass, read in the LMB information */
423 lmb_index = 0;
424 p = prop;
425 first = NULL;
426
427 for (i = 0; i < lmb_sets; i++) {
428 read_drconf_v2_cell(&dr_cell, &p);
429
430 /*
431 * Fetch the NUMA node id for the fist set or if the
432 * associativity index is different from the previous set.
433 */
434 if (first && dr_cell.aa_index != first->aa_index)
435 first = NULL;
436
437 for (j = 0; j < dr_cell.seq_lmbs; j++) {
438 lmb = &drmem_info->lmbs[lmb_index++];
439
440 lmb->base_addr = dr_cell.base_addr;
441 dr_cell.base_addr += drmem_info->lmb_size;
442
443 lmb->drc_index = dr_cell.drc_index;
444 dr_cell.drc_index++;
445
446 lmb->aa_index = dr_cell.aa_index;
447 lmb->flags = dr_cell.flags;
448
449 /*
450 * All the LMB in the set share the same NUMA
451 * associativity property. So read that node only once.
452 */
453 if (!first) {
454 lmb_set_nid(lmb);
455 first = lmb;
456 } else {
> 457 lmb->nid = first->nid;
458 }
459 }
460 }
461 }
462
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]
All the LMB from the same set of ibm,dynamic-memory-v2 property are
sharing the same NUMA node. Don't compute that node for each one.
Tested on a system with 1022 LMBs spread on 4 NUMA nodes, only 4 calls to
lmb_set_nid() have been made instead of 1022.
This should prevent some soft lockups when starting large guests
Code has meaning only if CONFIG_MEMORY_HOTPLUG is set, otherwise the nid
field is not present in the drmem_lmb structure.
Signed-off-by: Laurent Dufour <[email protected]>
---
arch/powerpc/mm/drmem.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index b2eeea39684c..c11b6ec99ea3 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -402,6 +402,9 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
const __be32 *p;
u32 i, j, lmb_sets;
int lmb_index;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ struct drmem_lmb *first = NULL;
+#endif
lmb_sets = of_read_number(prop++, 1);
if (lmb_sets == 0)
@@ -426,6 +429,15 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
for (i = 0; i < lmb_sets; i++) {
read_drconf_v2_cell(&dr_cell, &p);
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * Fetch the NUMA node id for the fist set or if the
+ * associativity index is different from the previous set.
+ */
+ if (first && dr_cell.aa_index != first->aa_index)
+ first = NULL;
+#endif
+
for (j = 0; j < dr_cell.seq_lmbs; j++) {
lmb = &drmem_info->lmbs[lmb_index++];
@@ -438,7 +450,18 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
lmb->aa_index = dr_cell.aa_index;
lmb->flags = dr_cell.flags;
- lmb_set_nid(lmb);
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * All the LMB in the set share the same NUMA
+ * associativity property. So read that node only once.
+ */
+ if (!first) {
+ lmb_set_nid(lmb);
+ first = lmb;
+ } else {
+ lmb->nid = first->nid;
+ }
+#endif
}
}
}
--
2.28.0
Le 05/08/2020 ? 12:43, kernel test robot a ?crit?:
> Hi Laurent,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on powerpc/next]
> [also build test ERROR on linux/master linus/master v5.8 next-20200804]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]
>
> url: https://github.com/0day-ci/linux/commits/Laurent-Dufour/powerpc-drmem-Don-t-compute-the-NUMA-node-for-each-LMB/20200805-173213
> base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> config: powerpc-mpc885_ads_defconfig (attached as .config)
> compiler: powerpc-linux-gcc (GCC) 9.3.0
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <[email protected]>
>
> All errors (new ones prefixed by >>):
>
> arch/powerpc/mm/drmem.c: In function 'init_drmem_v2_lmbs':
>>> arch/powerpc/mm/drmem.c:457:8: error: 'struct drmem_lmb' has no member named 'nid'
> 457 | lmb->nid = first->nid;
> | ^~
> arch/powerpc/mm/drmem.c:457:21: error: 'struct drmem_lmb' has no member named 'nid'
> 457 | lmb->nid = first->nid;
> | ^~
My mistake, the nid member is only present when CONFIG_MEMORY_HOTPLUG is set.
I'll send a new version fixing this.
> vim +457 arch/powerpc/mm/drmem.c
>
> 397
> 398 static void __init init_drmem_v2_lmbs(const __be32 *prop)
> 399 {
> 400 struct drmem_lmb *lmb, *first;
> 401 struct of_drconf_cell_v2 dr_cell;
> 402 const __be32 *p;
> 403 u32 i, j, lmb_sets;
> 404 int lmb_index;
> 405
> 406 lmb_sets = of_read_number(prop++, 1);
> 407 if (lmb_sets == 0)
> 408 return;
> 409
> 410 /* first pass, calculate the number of LMBs */
> 411 p = prop;
> 412 for (i = 0; i < lmb_sets; i++) {
> 413 read_drconf_v2_cell(&dr_cell, &p);
> 414 drmem_info->n_lmbs += dr_cell.seq_lmbs;
> 415 }
> 416
> 417 drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
> 418 GFP_KERNEL);
> 419 if (!drmem_info->lmbs)
> 420 return;
> 421
> 422 /* second pass, read in the LMB information */
> 423 lmb_index = 0;
> 424 p = prop;
> 425 first = NULL;
> 426
> 427 for (i = 0; i < lmb_sets; i++) {
> 428 read_drconf_v2_cell(&dr_cell, &p);
> 429
> 430 /*
> 431 * Fetch the NUMA node id for the fist set or if the
> 432 * associativity index is different from the previous set.
> 433 */
> 434 if (first && dr_cell.aa_index != first->aa_index)
> 435 first = NULL;
> 436
> 437 for (j = 0; j < dr_cell.seq_lmbs; j++) {
> 438 lmb = &drmem_info->lmbs[lmb_index++];
> 439
> 440 lmb->base_addr = dr_cell.base_addr;
> 441 dr_cell.base_addr += drmem_info->lmb_size;
> 442
> 443 lmb->drc_index = dr_cell.drc_index;
> 444 dr_cell.drc_index++;
> 445
> 446 lmb->aa_index = dr_cell.aa_index;
> 447 lmb->flags = dr_cell.flags;
> 448
> 449 /*
> 450 * All the LMB in the set share the same NUMA
> 451 * associativity property. So read that node only once.
> 452 */
> 453 if (!first) {
> 454 lmb_set_nid(lmb);
> 455 first = lmb;
> 456 } else {
> > 457 lmb->nid = first->nid;
> 458 }
> 459 }
> 460 }
> 461 }
> 462
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/[email protected]
>
Le 05/08/2020 à 15:35, Laurent Dufour a écrit :
> All the LMB from the same set of ibm,dynamic-memory-v2 property are
> sharing the same NUMA node. Don't compute that node for each one.
>
> Tested on a system with 1022 LMBs spread on 4 NUMA nodes, only 4 calls to
> lmb_set_nid() have been made instead of 1022.
>
> This should prevent some soft lockups when starting large guests
>
> Code has meaning only if CONFIG_MEMORY_HOTPLUG is set, otherwise the nid
> field is not present in the drmem_lmb structure.
>
> Signed-off-by: Laurent Dufour <[email protected]>
It looks like this patch was superseded by e5e179aa3a39 ("pseries/drmem:
don't cache node id in drmem_lmb struct").
If not, anyway it conflicts with that patch so it has to be rebased.
Thanks
Christophe
> ---
> arch/powerpc/mm/drmem.c | 25 ++++++++++++++++++++++++-
> 1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
> index b2eeea39684c..c11b6ec99ea3 100644
> --- a/arch/powerpc/mm/drmem.c
> +++ b/arch/powerpc/mm/drmem.c
> @@ -402,6 +402,9 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
> const __be32 *p;
> u32 i, j, lmb_sets;
> int lmb_index;
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + struct drmem_lmb *first = NULL;
> +#endif
>
> lmb_sets = of_read_number(prop++, 1);
> if (lmb_sets == 0)
> @@ -426,6 +429,15 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
> for (i = 0; i < lmb_sets; i++) {
> read_drconf_v2_cell(&dr_cell, &p);
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /*
> + * Fetch the NUMA node id for the fist set or if the
> + * associativity index is different from the previous set.
> + */
> + if (first && dr_cell.aa_index != first->aa_index)
> + first = NULL;
> +#endif
> +
> for (j = 0; j < dr_cell.seq_lmbs; j++) {
> lmb = &drmem_info->lmbs[lmb_index++];
>
> @@ -438,7 +450,18 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
> lmb->aa_index = dr_cell.aa_index;
> lmb->flags = dr_cell.flags;
>
> - lmb_set_nid(lmb);
> +#ifdef CONFIG_MEMORY_HOTPLUG
> + /*
> + * All the LMB in the set share the same NUMA
> + * associativity property. So read that node only once.
> + */
> + if (!first) {
> + lmb_set_nid(lmb);
> + first = lmb;
> + } else {
> + lmb->nid = first->nid;
> + }
> +#endif
> }
> }
> }
On 02/04/2022, 18:35:15, Christophe Leroy wrote:
>
>
> Le 05/08/2020 à 15:35, Laurent Dufour a écrit :
>> All the LMB from the same set of ibm,dynamic-memory-v2 property are
>> sharing the same NUMA node. Don't compute that node for each one.
>>
>> Tested on a system with 1022 LMBs spread on 4 NUMA nodes, only 4 calls to
>> lmb_set_nid() have been made instead of 1022.
>>
>> This should prevent some soft lockups when starting large guests
>>
>> Code has meaning only if CONFIG_MEMORY_HOTPLUG is set, otherwise the nid
>> field is not present in the drmem_lmb structure.
>>
>> Signed-off-by: Laurent Dufour <[email protected]>
>
> It looks like this patch was superseded by e5e179aa3a39 ("pseries/drmem:
> don't cache node id in drmem_lmb struct").
That patch has been superseded and can be dropped.
Thanks,
Laurent.
> If not, anyway it conflicts with that patch so it has to be rebased.
>
> Thanks
> Christophe
>
>
>> ---
>> arch/powerpc/mm/drmem.c | 25 ++++++++++++++++++++++++-
>> 1 file changed, 24 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
>> index b2eeea39684c..c11b6ec99ea3 100644
>> --- a/arch/powerpc/mm/drmem.c
>> +++ b/arch/powerpc/mm/drmem.c
>> @@ -402,6 +402,9 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> const __be32 *p;
>> u32 i, j, lmb_sets;
>> int lmb_index;
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> + struct drmem_lmb *first = NULL;
>> +#endif
>> lmb_sets = of_read_number(prop++, 1);
>> if (lmb_sets == 0)
>> @@ -426,6 +429,15 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> for (i = 0; i < lmb_sets; i++) {
>> read_drconf_v2_cell(&dr_cell, &p);
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> + /*
>> + * Fetch the NUMA node id for the fist set or if the
>> + * associativity index is different from the previous set.
>> + */
>> + if (first && dr_cell.aa_index != first->aa_index)
>> + first = NULL;
>> +#endif
>> +
>> for (j = 0; j < dr_cell.seq_lmbs; j++) {
>> lmb = &drmem_info->lmbs[lmb_index++];
>> @@ -438,7 +450,18 @@ static void __init init_drmem_v2_lmbs(const __be32
>> *prop)
>> lmb->aa_index = dr_cell.aa_index;
>> lmb->flags = dr_cell.flags;
>> - lmb_set_nid(lmb);
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> + /*
>> + * All the LMB in the set share the same NUMA
>> + * associativity property. So read that node only once.
>> + */
>> + if (!first) {
>> + lmb_set_nid(lmb);
>> + first = lmb;
>> + } else {
>> + lmb->nid = first->nid;
>> + }
>> +#endif
>> }
>> }
>> }