From: "hch@infradead.org" <hch@infradead.org>
To: Atish Patra <Atish.Patra@wdc.com>
Cc: "hch@infradead.org" <hch@infradead.org>,
"aou@eecs.berkeley.edu" <aou@eecs.berkeley.edu>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
Anup Patel <Anup.Patel@wdc.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"alexios.zavras@intel.com" <alexios.zavras@intel.com>,
"palmer@sifive.com" <palmer@sifive.com>,
"paul.walmsley@sifive.com" <paul.walmsley@sifive.com>,
"linux-riscv@lists.infradead.org"
<linux-riscv@lists.infradead.org>,
"allison@lohutok.net" <allison@lohutok.net>
Subject: Re: [PATCH] RISC-V: Issue a local tlb flush if possible.
Date: Tue, 13 Aug 2019 07:30:27 -0700 [thread overview]
Message-ID: <20190813143027.GA31668@infradead.org> (raw)
In-Reply-To: <f58814e156b918531f058acfac944abef34f5fb1.camel@wdc.com>
On Tue, Aug 13, 2019 at 12:15:15AM +0000, Atish Patra wrote:
> I thought if it recieves an empty cpumask, then it should at least do a
> local flush is the expected behavior. Are you saying that we should
> just skip all and return ?
How could we ever receive an empty cpu mask? I think it could only
be empty without the current cpu. At least that is my reading of
the callers and a few other implementations.
> > if (!cpumask || cpumask_test_cpu(cpu, cpumask) {
> > if ((start == 0 && size == -1) || size > PAGE_SIZE)
> > local_flush_tlb_all();
> > else if (size == PAGE_SIZE)
> > local_flush_tlb_page(start);
> > cpumask_clear_cpu(cpuid, cpumask);
>
> This will modify the original cpumask which is not correct. clear part
> has to be done on hmask to avoid a copy.
Indeed. But looking at the x86 tlbflush implementation it seems like we
could use cpumask_any_but() to avoid having to modify the passed in
cpumask.
next prev parent reply other threads:[~2019-08-13 14:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-10 1:43 [PATCH] RISC-V: Issue a local tlb flush if possible Atish Patra
2019-08-10 3:30 ` Anup Patel
2019-08-10 5:28 ` Atish Patra
2019-08-10 6:37 ` Andreas Schwab
2019-08-10 9:21 ` Atish Patra
2019-08-12 14:56 ` Christoph Hellwig
2019-08-13 0:15 ` Atish Patra
2019-08-13 14:30 ` hch [this message]
2019-08-15 20:37 ` Atish Patra
2019-08-19 14:46 ` hch
2019-08-19 15:09 ` Anup Patel
2019-08-19 15:10 ` hch
2019-08-20 0:02 ` Atish Patra
2019-08-12 15:36 ` Troy Benjegerdes
2019-08-12 17:13 ` Atish Patra
2019-08-12 17:55 ` Christoph Hellwig
2019-08-13 18:25 ` Paul Walmsley
2019-08-14 1:49 ` Atish Patra
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