Re: [PATCH v5 07/14] memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section()
(2012/12/24 21:09), Tang Chen wrote: In __remove_section(), we locked pgdat_resize_lock when calling sparse_remove_one_section(). This lock will disable irq. But we don't need to lock the whole function. If we do some work to free pagetables in free_section_usemap(), we need to call flush_tlb_all(), which need irq enabled. Otherwise the WARN_ON_ONCE() in smp_call_function_many() will be triggered. Signed-off-by: Tang Chen tangc...@cn.fujitsu.com Signed-off-by: Lai Jiangshan la...@cn.fujitsu.com Signed-off-by: Wen Congyang we...@cn.fujitsu.com If this is a bug fix, call-trace in your log and BUGFIX or -fix- in patch title will be appreciated, I think. Acked-by: KAMEZAWA Hiroyuki kamezawa.hir...@jp.fujitsu.com ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v5 07/14] memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section()
On 12/26/2012 11:47 AM, Kamezawa Hiroyuki wrote: (2012/12/24 21:09), Tang Chen wrote: In __remove_section(), we locked pgdat_resize_lock when calling sparse_remove_one_section(). This lock will disable irq. But we don't need to lock the whole function. If we do some work to free pagetables in free_section_usemap(), we need to call flush_tlb_all(), which need irq enabled. Otherwise the WARN_ON_ONCE() in smp_call_function_many() will be triggered. Signed-off-by: Tang Chentangc...@cn.fujitsu.com Signed-off-by: Lai Jiangshanla...@cn.fujitsu.com Signed-off-by: Wen Congyangwe...@cn.fujitsu.com If this is a bug fix, call-trace in your log and BUGFIX or -fix- in patch title will be appreciated, I think. Acked-by: KAMEZAWA Hiroyukikamezawa.hir...@jp.fujitsu.com Hi Kamezawa-san, Thanks for the reviewing. I don't think this would be a bug. It is OK to lock the whole sparse_remove_one_section() if no tlb flushing in free_section_usemap(). But we need to flush tlb in free_section_usemap(), so we need to take free_section_usemap() out of the lock. :) I add the call trace to the patch so that people could review it more easily. And here is the call trace for this version: [ 454.796248] [ cut here ] [ 454.851408] WARNING: at kernel/smp.c:461 smp_call_function_many+0xbd/0x260() [ 454.935620] Hardware name: PRIMEQUEST 1800E .. [ 455.652201] Call Trace: [ 455.681391] [8106e73f] warn_slowpath_common+0x7f/0xc0 [ 455.753151] [810560a0] ? leave_mm+0x50/0x50 [ 455.814527] [8106e79a] warn_slowpath_null+0x1a/0x20 [ 455.884208] [810e7a9d] smp_call_function_many+0xbd/0x260 [ 455.959082] [810e7ecb] smp_call_function+0x3b/0x50 [ 456.027722] [810560a0] ? leave_mm+0x50/0x50 [ 456.089098] [810e7f4b] on_each_cpu+0x3b/0xc0 [ 456.151512] [81055f0c] flush_tlb_all+0x1c/0x20 [ 456.216004] [8104f8de] remove_pagetable+0x14e/0x1d0 [ 456.285683] [8104f978] vmemmap_free+0x18/0x20 [ 456.349139] [811b8797] sparse_remove_one_section+0xf7/0x100 [ 456.427126] [811c5fc2] __remove_section+0xa2/0xb0 [ 456.494726] [811c6070] __remove_pages+0xa0/0xd0 [ 456.560258] [81669c7b] arch_remove_memory+0x6b/0xc0 [ 456.629937] [8166ad28] remove_memory+0xb8/0xf0 [ 456.694431] [813e686f] acpi_memory_device_remove+0x53/0x96 [ 456.771379] [813b33c4] acpi_device_remove+0x90/0xb2 [ 456.841059] [8144b02c] __device_release_driver+0x7c/0xf0 [ 456.915928] [8144b1af] device_release_driver+0x2f/0x50 [ 456.988719] [813b4476] acpi_bus_remove+0x32/0x6d [ 457.055285] [813b4542] acpi_bus_trim+0x91/0x102 [ 457.120814] [813b463b] acpi_bus_hot_remove_device+0x88/0x16b [ 457.199840] [813afda7] acpi_os_execute_deferred+0x27/0x34 [ 457.275756] [81091ece] process_one_work+0x20e/0x5c0 [ 457.345434] [81091e5f] ? process_one_work+0x19f/0x5c0 [ 457.417190] [813afd80] ? acpi_os_wait_events_complete+0x23/0x23 [ 457.499332] [81093f6e] worker_thread+0x12e/0x370 [ 457.565896] [81093e40] ? manage_workers+0x180/0x180 [ 457.635574] [8109a09e] kthread+0xee/0x100 [ 457.694871] [810dfaf9] ? __lock_release+0x129/0x190 [ 457.764552] [81099fb0] ? __init_kthread_worker+0x70/0x70 [ 457.839427] [81690aac] ret_from_fork+0x7c/0xb0 [ 457.903914] [81099fb0] ? __init_kthread_worker+0x70/0x70 [ 457.978784] ---[ end trace 25e85300f542aa01 ]--- Thanks. :) ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH v5 07/14] memory-hotplug: move pgdat_resize_lock into sparse_remove_one_section()
In __remove_section(), we locked pgdat_resize_lock when calling
sparse_remove_one_section(). This lock will disable irq. But we don't need
to lock the whole function. If we do some work to free pagetables in
free_section_usemap(), we need to call flush_tlb_all(), which need
irq enabled. Otherwise the WARN_ON_ONCE() in smp_call_function_many()
will be triggered.
Signed-off-by: Tang Chen tangc...@cn.fujitsu.com
Signed-off-by: Lai Jiangshan la...@cn.fujitsu.com
Signed-off-by: Wen Congyang we...@cn.fujitsu.com
---
mm/memory_hotplug.c |4
mm/sparse.c |5 -
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 34c656b..c12bd55 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -442,8 +442,6 @@ static int __remove_section(struct zone *zone, struct
mem_section *ms)
#else
static int __remove_section(struct zone *zone, struct mem_section *ms)
{
- unsigned long flags;
- struct pglist_data *pgdat = zone-zone_pgdat;
int ret = -EINVAL;
if (!valid_section(ms))
@@ -453,9 +451,7 @@ static int __remove_section(struct zone *zone, struct
mem_section *ms)
if (ret)
return ret;
- pgdat_resize_lock(pgdat, flags);
sparse_remove_one_section(zone, ms);
- pgdat_resize_unlock(pgdat, flags);
return 0;
}
#endif
diff --git a/mm/sparse.c b/mm/sparse.c
index aadbb2a..05ca73a 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -796,8 +796,10 @@ static inline void clear_hwpoisoned_pages(struct page
*memmap, int nr_pages)
void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
{
struct page *memmap = NULL;
- unsigned long *usemap = NULL;
+ unsigned long *usemap = NULL, flags;
+ struct pglist_data *pgdat = zone-zone_pgdat;
+ pgdat_resize_lock(pgdat, flags);
if (ms-section_mem_map) {
usemap = ms-pageblock_flags;
memmap = sparse_decode_mem_map(ms-section_mem_map,
@@ -805,6 +807,7 @@ void sparse_remove_one_section(struct zone *zone, struct
mem_section *ms)
ms-section_mem_map = 0;
ms-pageblock_flags = NULL;
}
+ pgdat_resize_unlock(pgdat, flags);
clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
free_section_usemap(memmap, usemap);
--
1.7.1
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