From: Paul Burton <paul.burton@mips.com>
To: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: Paul Burton <pburton@wavecomp.com>
Subject: [PATCH 04/14] MIPS: mm: Avoid HTW stop/start when dropping an inactive mm
Date: Sat, 2 Feb 2019 01:43:18 +0000 [thread overview]
Message-ID: <20190202014242.30680-5-paul.burton@mips.com> (raw)
In-Reply-To: <20190202014242.30680-1-paul.burton@mips.com>
If drop_mmu_context() is called with an mm that is not currently active
on the local CPU then there's no need for us to stop & start a hardware
page table walker because it can't be fetching entries for the ASID
corresponding to the mm we're operating on.
Move the htw_stop() & htw_start() calls into the block which we run only
if the mm is currently active, in order to avoid the redundant work.
Signed-off-by: Paul Burton <paul.burton@mips.com>
---
arch/mips/include/asm/mmu_context.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index 0d050d781737..5d0a73a5cf40 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -184,17 +184,18 @@ drop_mmu_context(struct mm_struct *mm)
unsigned int cpu;
local_irq_save(flags);
- htw_stop();
cpu = smp_processor_id();
if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
+ htw_stop();
get_new_mmu_context(mm);
write_c0_entryhi(cpu_asid(cpu, mm));
+ htw_start();
} else {
/* will get a new context next time */
cpu_context(cpu, mm) = 0;
}
- htw_start();
+
local_irq_restore(flags);
}
--
2.20.1
next prev parent reply other threads:[~2019-02-02 1:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-02 1:43 [PATCH 00/14] MIPS: MemoryMapID (MMID) & GINVT Support Paul Burton
2019-02-02 1:43 ` [PATCH 01/14] MIPS: mm: Define activate_mm() using switch_mm() Paul Burton
2019-02-02 1:43 ` [PATCH 02/14] MIPS: mm: Remove redundant drop_mmu_context() cpu argument Paul Burton
2019-02-02 1:43 ` [PATCH 03/14] MIPS: mm: Remove redundant get_new_mmu_context() " Paul Burton
2019-02-02 1:43 ` Paul Burton [this message]
2019-02-02 1:43 ` [PATCH 05/14] MIPS: mm: Consolidate drop_mmu_context() has-ASID checks Paul Burton
2019-02-02 1:43 ` [PATCH 06/14] MIPS: mm: Move drop_mmu_context() comment into appropriate block Paul Burton
2019-02-02 1:43 ` [PATCH 07/14] MIPS: mm: Remove redundant preempt_disable in local_flush_tlb_mm() Paul Burton
2019-02-02 1:43 ` [PATCH 08/14] MIPS: mm: Remove local_flush_tlb_mm() Paul Burton
2019-02-02 1:43 ` [PATCH 09/14] MIPS: mm: Split obj-y to a file per line Paul Burton
2019-02-02 1:43 ` [PATCH 10/14] MIPS: mm: Un-inline get_new_mmu_context Paul Burton
2019-02-02 1:43 ` [PATCH 12/14] MIPS: mm: Add set_cpu_context() for ASID assignments Paul Burton
2019-02-02 1:43 ` [PATCH 11/14] MIPS: mm: Unify ASID version checks Paul Burton
2019-02-02 1:43 ` [PATCH 13/14] MIPS: Add GINVT instruction helpers Paul Burton
2019-02-02 1:43 ` [PATCH 14/14] MIPS: MemoryMapID (MMID) Support Paul Burton
2019-02-04 21:18 ` [PATCH 00/14] MIPS: MemoryMapID (MMID) & GINVT Support Paul Burton
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