From: Leonardo Bras <leonardo@linux.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Arnd Bergmann <arnd@arndb.de>,
Andrew Morton <akpm@linux-foundation.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@c-s.fr>,
Steven Price <steven.price@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
Leonardo Bras <leonardo@linux.ibm.com>,
Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
Balbir Singh <bsingharora@gmail.com>,
Reza Arbab <arbab@linux.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Allison Randal <allison@lohutok.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mike Rapoport <rppt@linux.ibm.com>,
Michal Suchanek <msuchanek@suse.de>
Cc: linux-arch@vger.kernel.org, linux-mm@kvack.org,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: [PATCH v6 02/11] mm/gup: Use functions to track lockless pgtbl walks on gup_pgd_range
Date: Thu, 6 Feb 2020 00:08:51 -0300 [thread overview]
Message-ID: <20200206030900.147032-3-leonardo@linux.ibm.com> (raw)
In-Reply-To: <20200206030900.147032-1-leonardo@linux.ibm.com>
As described, gup_pgd_range is a lockless pagetable walk. So, in order to
track against THP split/collapse, it disables/enables irq around it.
To make use of the new tracking functions, it replaces irq disable/enable
by {begin,end}_lockless_pgtbl_walk().
As local_irq_{save,restore} is present inside
{begin,end}_lockless_pgtbl_walk, there should be no change in the
workings.
Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
---
mm/gup.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c
index 1b521e0ac1de..04e6f46993b6 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2369,7 +2369,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages)
{
unsigned long len, end;
- unsigned long flags;
+ unsigned long irq_mask;
int nr = 0;
start = untagged_addr(start) & PAGE_MASK;
@@ -2395,9 +2395,9 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) &&
gup_fast_permitted(start, end)) {
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk();
gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr);
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(irq_mask);
}
return nr;
@@ -2450,9 +2450,9 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages,
if (IS_ENABLED(CONFIG_HAVE_FAST_GUP) &&
gup_fast_permitted(start, end)) {
- local_irq_disable();
+ begin_lockless_pgtbl_walk();
gup_pgd_range(addr, end, gup_flags, pages, &nr);
- local_irq_enable();
+ end_lockless_pgtbl_walk(IRQS_ENABLED);
ret = nr;
}
--
2.24.1
next prev parent reply other threads:[~2020-02-06 3:19 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 3:08 [PATCH v6 00/11] Introduces new functions for tracking lockless pagetable walks Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 01/11] asm-generic/pgtable: Adds generic functions to track lockless pgtable walks Leonardo Bras
2020-02-06 5:54 ` Christophe Leroy
2020-02-07 2:19 ` Leonardo Bras
2020-02-07 5:39 ` kbuild test robot
2020-02-06 3:08 ` Leonardo Bras [this message]
2020-02-06 3:25 ` [PATCH v6 02/11] mm/gup: Use functions to track lockless pgtbl walks on gup_pgd_range Leonardo Bras
2020-02-07 22:54 ` John Hubbard
2020-02-17 20:55 ` Leonardo Bras
2020-10-15 14:46 ` Michal Suchánek
2020-10-16 3:27 ` Aneesh Kumar K.V
2020-02-07 1:19 ` kbuild test robot
2020-02-07 8:01 ` kbuild test robot
2020-02-06 3:08 ` [PATCH v6 03/11] powerpc/mm: Adds arch-specificic functions to track lockless pgtable walks Leonardo Bras
2020-02-06 5:46 ` Christophe Leroy
2020-02-07 4:38 ` Leonardo Bras
2020-02-17 20:32 ` Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 04/11] powerpc/mce_power: Use functions to track lockless pgtbl walks Leonardo Bras
2020-02-06 5:48 ` Christophe Leroy
2020-02-07 4:00 ` Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 05/11] powerpc/perf: " Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 06/11] powerpc/mm/book3s64/hash: " Leonardo Bras
2020-02-06 6:06 ` Christophe Leroy
2020-02-07 3:49 ` Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 07/11] powerpc/kvm/e500: " Leonardo Bras
2020-02-06 6:18 ` Christophe Leroy
2020-02-07 3:10 ` Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 08/11] powerpc/kvm/book3s_hv: " Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 09/11] powerpc/kvm/book3s_64: " Leonardo Bras
2020-02-06 3:08 ` [PATCH v6 10/11] powerpc/mm: Adds counting method to track lockless pagetable walks Leonardo Bras
2020-02-06 6:23 ` Christophe Leroy
2020-02-07 1:56 ` Leonardo Bras
2020-02-06 3:09 ` [PATCH v6 11/11] powerpc/mm/book3s64/pgtable: Uses counting method to skip serializing Leonardo Bras
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