From: tip-bot for Dan Williams <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: dave.hansen@linux.intel.com, linux-kernel@vger.kernel.org,
dan.j.williams@intel.com, torvalds@linux-foundation.org,
stable@vger.kernel.org, mingo@kernel.org, bp@alien8.de,
luto@kernel.org, bigeasy@linutronix.de, peterz@infradead.org,
riel@surriel.com, tglx@linutronix.de,
kirill.shutemov@linux.intel.com, hpa@zytor.com
Subject: [tip:x86/mm] x86/mm: Drop usage of __flush_tlb_all() in kernel_physical_mapping_init()
Date: Wed, 5 Dec 2018 10:07:20 -0800 [thread overview]
Message-ID: <tip-ba6f508d0ec4adb09f0a939af6d5e19cdfa8667d@git.kernel.org> (raw)
In-Reply-To: <154395944713.32119.15611079023837132638.stgit@dwillia2-desk3.amr.corp.intel.com>
Commit-ID: ba6f508d0ec4adb09f0a939af6d5e19cdfa8667d
Gitweb: https://git.kernel.org/tip/ba6f508d0ec4adb09f0a939af6d5e19cdfa8667d
Author: Dan Williams <dan.j.williams@intel.com>
AuthorDate: Tue, 4 Dec 2018 13:37:27 -0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 5 Dec 2018 09:03:07 +0100
x86/mm: Drop usage of __flush_tlb_all() in kernel_physical_mapping_init()
Commit:
f77084d96355 "x86/mm/pat: Disable preemption around __flush_tlb_all()"
addressed a case where __flush_tlb_all() is called without preemption
being disabled. It also left a warning to catch other cases where
preemption is not disabled.
That warning triggers for the memory hotplug path which is also used for
persistent memory enabling:
WARNING: CPU: 35 PID: 911 at ./arch/x86/include/asm/tlbflush.h:460
RIP: 0010:__flush_tlb_all+0x1b/0x3a
[..]
Call Trace:
phys_pud_init+0x29c/0x2bb
kernel_physical_mapping_init+0xfc/0x219
init_memory_mapping+0x1a5/0x3b0
arch_add_memory+0x2c/0x50
devm_memremap_pages+0x3aa/0x610
pmem_attach_disk+0x585/0x700 [nd_pmem]
Andy wondered why a path that can sleep was using __flush_tlb_all() [1]
and Dave confirmed the expectation for TLB flush is for modifying /
invalidating existing PTE entries, but not initial population [2]. Drop
the usage of __flush_tlb_all() in phys_{p4d,pud,pmd}_init() on the
expectation that this path is only ever populating empty entries for the
linear map. Note, at linear map teardown time there is a call to the
all-cpu flush_tlb_all() to invalidate the removed mappings.
[1]: https://lkml.kernel.org/r/9DFD717D-857D-493D-A606-B635D72BAC21@amacapital.net
[2]: https://lkml.kernel.org/r/749919a4-cdb1-48a3-adb4-adb81a5fa0b5@intel.com
[ mingo: Minor readability edits. ]
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Fixes: f77084d96355 ("x86/mm/pat: Disable preemption around __flush_tlb_all()")
Link: http://lkml.kernel.org/r/154395944713.32119.15611079023837132638.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/mm/init_64.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3e25ac2793ef..484c1b92f078 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -584,7 +584,6 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
paddr_end,
page_size_mask,
prot);
- __flush_tlb_all();
continue;
}
/*
@@ -627,7 +626,6 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
pud_populate_safe(&init_mm, pud, pmd);
spin_unlock(&init_mm.page_table_lock);
}
- __flush_tlb_all();
update_page_count(PG_LEVEL_1G, pages);
@@ -668,7 +666,6 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
paddr_last = phys_pud_init(pud, paddr,
paddr_end,
page_size_mask);
- __flush_tlb_all();
continue;
}
@@ -680,7 +677,6 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
p4d_populate_safe(&init_mm, p4d, pud);
spin_unlock(&init_mm.page_table_lock);
}
- __flush_tlb_all();
return paddr_last;
}
@@ -733,8 +729,6 @@ kernel_physical_mapping_init(unsigned long paddr_start,
if (pgd_changed)
sync_global_pgds(vaddr_start, vaddr_end - 1);
- __flush_tlb_all();
-
return paddr_last;
}
prev parent reply other threads:[~2018-12-05 18:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-04 21:37 [PATCH v3 0/5] x86/mm: Drop usage of __flush_tlb_all() in kernel_physical_mapping_init() Dan Williams
2018-12-04 21:37 ` [PATCH v3 1/5] generic/pgtable: Make {pmd, pud}_same() unconditionally available Dan Williams
2018-12-05 18:05 ` [tip:x86/mm] " tip-bot for Dan Williams
2018-12-04 21:37 ` [PATCH v3 2/5] generic/pgtable: Introduce {p4d,pgd}_same() Dan Williams
2018-12-05 18:05 ` [tip:x86/mm] " tip-bot for Dan Williams
2018-12-04 21:37 ` [PATCH v3 3/5] generic/pgtable: Introduce set_pte_safe() Dan Williams
2018-12-04 21:37 ` [PATCH v3 4/5] x86/mm: Validate kernel_physical_mapping_init() pte population Dan Williams
2018-12-05 18:06 ` [tip:x86/mm] x86/mm: Validate kernel_physical_mapping_init() PTE population tip-bot for Dan Williams
2018-12-04 21:37 ` [PATCH v3 5/5] x86/mm: Drop usage of __flush_tlb_all() in kernel_physical_mapping_init() Dan Williams
2018-12-05 18:07 ` tip-bot for Dan Williams [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tip-ba6f508d0ec4adb09f0a939af6d5e19cdfa8667d@git.kernel.org \
--to=tipbot@zytor.com \
--cc=bigeasy@linutronix.de \
--cc=bp@alien8.de \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=riel@surriel.com \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).