From: Qian Cai <cai@lca.pw>
To: Steven Price <Steven.Price@arm.com>
Cc: "kbuild test robot" <lkp@intel.com>,
"Mark Rutland" <Mark.Rutland@arm.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
linux-mm@kvack.org, "H. Peter Anvin" <hpa@zytor.com>,
"Will Deacon" <will@kernel.org>,
"Liang, Kan" <kan.liang@linux.intel.com>,
x86@kernel.org, "Ingo Molnar" <mingo@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
linux-arm-kernel@lists.infradead.org, kbuild-all@lists.01.org,
"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org, "James Morse" <James.Morse@arm.com>,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: Re: [PATCH v16 13/25] mm: pagewalk: Don't lock PTEs for walk_page_range_novma()
Date: Wed, 11 Dec 2019 12:19:35 -0500 [thread overview]
Message-ID: <728FAC8D-AA0C-4326-8990-A3D5D0DA1EE5@lca.pw> (raw)
In-Reply-To: <e0fd5594-fb4e-9ead-e582-544f47cb1f8b@arm.com>
> On Dec 11, 2019, at 10:54 AM, Steven Price <Steven.Price@arm.com> wrote:
>
> I believe this is a false positive (although the trace here is useless).
> This patch adds a conditional lock/unlock:
>
> pte = walk->no_vma ? pte_offset_map(pmd, addr) :
> pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
> ...
> if (!walk->no_vma)
> spin_unlock(ptl);
> pte_unmap(pte);
>
> I'm not sure how to match sparse happy about that. Is the only option to
> have two versions of the walk_pte_range() function? One which takes the
> lock and one which doesn't.
Or just ignore the sparse false positive without complicating the code further.
next prev parent reply other threads:[~2019-12-11 17:19 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-06 13:52 [PATCH v16 00/25] Generic page walk and ptdump Steven Price
2019-12-06 13:52 ` [PATCH v16 01/25] mm: Add generic p?d_leaf() macros Steven Price
2019-12-06 13:52 ` [PATCH v16 02/25] arc: mm: Add p?d_leaf() definitions Steven Price
2019-12-06 13:52 ` [PATCH v16 03/25] arm: " Steven Price
2019-12-06 13:52 ` [PATCH v16 04/25] arm64: " Steven Price
2019-12-06 13:52 ` [PATCH v16 05/25] mips: " Steven Price
2019-12-06 13:52 ` [PATCH v16 06/25] powerpc: " Steven Price
2019-12-09 11:08 ` Michael Ellerman
2019-12-09 13:06 ` Steven Price
2019-12-06 13:52 ` [PATCH v16 07/25] riscv: " Steven Price
2019-12-06 13:52 ` [PATCH v16 08/25] s390: " Steven Price
2019-12-06 13:53 ` [PATCH v16 09/25] sparc: " Steven Price
2019-12-06 13:53 ` [PATCH v16 10/25] x86: " Steven Price
2019-12-06 13:53 ` [PATCH v16 11/25] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-12-12 11:23 ` Thomas Hellström (VMware)
2019-12-12 11:33 ` Thomas Hellström (VMware)
2019-12-12 13:15 ` Steven Price
2019-12-12 14:04 ` Thomas Hellström (VMware)
2019-12-12 15:18 ` Steven Price
2019-12-06 13:53 ` [PATCH v16 12/25] mm: pagewalk: Allow walking without vma Steven Price
2019-12-06 13:53 ` [PATCH v16 13/25] mm: pagewalk: Don't lock PTEs for walk_page_range_novma() Steven Price
2019-12-10 11:23 ` kbuild test robot
2019-12-11 15:54 ` Steven Price
2019-12-11 17:12 ` Luc Van Oostenryck
2019-12-11 17:19 ` Qian Cai [this message]
2019-12-06 13:53 ` [PATCH v16 14/25] mm: pagewalk: fix termination condition in walk_pte_range() Steven Price
2019-12-06 13:53 ` [PATCH v16 15/25] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-12-06 13:53 ` [PATCH v16 16/25] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price
2019-12-06 13:53 ` [PATCH v16 17/25] x86: mm: Point to struct seq_file from struct pg_state Steven Price
2019-12-06 13:53 ` [PATCH v16 18/25] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-12-06 13:53 ` [PATCH v16 19/25] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-12-06 13:53 ` [PATCH v16 20/25] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-12-06 13:53 ` [PATCH v16 21/25] mm: Add generic ptdump Steven Price
2019-12-06 13:53 ` [PATCH v16 22/25] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price
2019-12-06 13:53 ` [PATCH v16 23/25] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-12-06 13:53 ` [PATCH v16 24/25] arm64: mm: Display non-present entries in ptdump Steven Price
2019-12-06 13:53 ` [PATCH v16 25/25] mm: ptdump: Reduce level numbers by 1 in note_page() Steven Price
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