| Message ID | 1356350964-13437-8-git-send-email-tangchen@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
(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 <tangchen@cn.fujitsu.com> > Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> > Signed-off-by: Wen Congyang <wency@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.hiroyu@jp.fujitsu.com> -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 Chen<tangchen@cn.fujitsu.com> >> Signed-off-by: Lai Jiangshan<laijs@cn.fujitsu.com> >> Signed-off-by: Wen Congyang<wency@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.hiroyu@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] [<ffffffff8106e73f>] warn_slowpath_common+0x7f/0xc0 [ 455.753151] [<ffffffff810560a0>] ? leave_mm+0x50/0x50 [ 455.814527] [<ffffffff8106e79a>] warn_slowpath_null+0x1a/0x20 [ 455.884208] [<ffffffff810e7a9d>] smp_call_function_many+0xbd/0x260 [ 455.959082] [<ffffffff810e7ecb>] smp_call_function+0x3b/0x50 [ 456.027722] [<ffffffff810560a0>] ? leave_mm+0x50/0x50 [ 456.089098] [<ffffffff810e7f4b>] on_each_cpu+0x3b/0xc0 [ 456.151512] [<ffffffff81055f0c>] flush_tlb_all+0x1c/0x20 [ 456.216004] [<ffffffff8104f8de>] remove_pagetable+0x14e/0x1d0 [ 456.285683] [<ffffffff8104f978>] vmemmap_free+0x18/0x20 [ 456.349139] [<ffffffff811b8797>] sparse_remove_one_section+0xf7/0x100 [ 456.427126] [<ffffffff811c5fc2>] __remove_section+0xa2/0xb0 [ 456.494726] [<ffffffff811c6070>] __remove_pages+0xa0/0xd0 [ 456.560258] [<ffffffff81669c7b>] arch_remove_memory+0x6b/0xc0 [ 456.629937] [<ffffffff8166ad28>] remove_memory+0xb8/0xf0 [ 456.694431] [<ffffffff813e686f>] acpi_memory_device_remove+0x53/0x96 [ 456.771379] [<ffffffff813b33c4>] acpi_device_remove+0x90/0xb2 [ 456.841059] [<ffffffff8144b02c>] __device_release_driver+0x7c/0xf0 [ 456.915928] [<ffffffff8144b1af>] device_release_driver+0x2f/0x50 [ 456.988719] [<ffffffff813b4476>] acpi_bus_remove+0x32/0x6d [ 457.055285] [<ffffffff813b4542>] acpi_bus_trim+0x91/0x102 [ 457.120814] [<ffffffff813b463b>] acpi_bus_hot_remove_device+0x88/0x16b [ 457.199840] [<ffffffff813afda7>] acpi_os_execute_deferred+0x27/0x34 [ 457.275756] [<ffffffff81091ece>] process_one_work+0x20e/0x5c0 [ 457.345434] [<ffffffff81091e5f>] ? process_one_work+0x19f/0x5c0 [ 457.417190] [<ffffffff813afd80>] ? acpi_os_wait_events_complete+0x23/0x23 [ 457.499332] [<ffffffff81093f6e>] worker_thread+0x12e/0x370 [ 457.565896] [<ffffffff81093e40>] ? manage_workers+0x180/0x180 [ 457.635574] [<ffffffff8109a09e>] kthread+0xee/0x100 [ 457.694871] [<ffffffff810dfaf9>] ? __lock_release+0x129/0x190 [ 457.764552] [<ffffffff81099fb0>] ? __init_kthread_worker+0x70/0x70 [ 457.839427] [<ffffffff81690aac>] ret_from_fork+0x7c/0xb0 [ 457.903914] [<ffffffff81099fb0>] ? __init_kthread_worker+0x70/0x70 [ 457.978784] ---[ end trace 25e85300f542aa01 ]--- Thanks. :) -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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);