From: Christoph Hellwig <hch@lst.de>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>,
Christoph Hellwig <hch@lst.de>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
"open list:LINUX FOR POWERPC PA SEMI PWRFICIENT"
<linuxppc-dev@lists.ozlabs.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
rth@twiddle.net, ink@jurassic.park.msu.ru,
Matt Turner <mattst88@gmail.com>,
linux-alpha@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-ia64@vger.kernel.org, schnelle@linux.ibm.com,
gerald.schaefer@linux.ibm.com, hca@linux.ibm.com,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
linux-s390@vger.kernel.org
Subject: Re: [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages()
Date: Thu, 3 Sep 2020 18:12:52 +0200 [thread overview]
Message-ID: <20200903161252.GA24841@lst.de> (raw)
In-Reply-To: <CAHp75VcVJBSnPQ6NfdF8FdEDfM+oQ=Sr+cH5VGX4SrAqrgpf-g@mail.gmail.com>
On Thu, Sep 03, 2020 at 01:57:39PM +0300, Andy Shevchenko wrote:
> > +{
> > + if (!dev)
> > + return (U32_MAX >> page_shift) + 1;
> > + return (dma_get_seg_boundary(dev) >> page_shift) + 1;
>
> Can it be better to do something like
> unsigned long boundary = dev ? dma_get_seg_boundary(dev) : U32_MAX;
>
> return (boundary >> page_shift) + 1;
>
> ?
I don't really see what that would buy us.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>,
Christoph Hellwig <hch@lst.de>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
"open list:LINUX FOR POWERPC PA SEMI PWRFICIENT"
<linuxppc-dev@lists.ozlabs.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
rth@twiddle.net, ink@jurassic.park.msu.ru,
Matt Turner <mattst88@gmail.com>,
linux-alpha@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-ia64@vger.kernel.org, schnelle@linux.ibm.com,
gerald.schaefer@linux.ibm.com, hca@linux.ibm.com,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
linux-s390@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
sparclinux@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Helge Deller <deller@gmx.de>,
linux-parisc@vger.kernel.org
Subject: Re: [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages()
Date: Thu, 03 Sep 2020 16:12:52 +0000 [thread overview]
Message-ID: <20200903161252.GA24841@lst.de> (raw)
In-Reply-To: <CAHp75VcVJBSnPQ6NfdF8FdEDfM+oQ=Sr+cH5VGX4SrAqrgpf-g@mail.gmail.com>
On Thu, Sep 03, 2020 at 01:57:39PM +0300, Andy Shevchenko wrote:
> > +{
> > + if (!dev)
> > + return (U32_MAX >> page_shift) + 1;
> > + return (dma_get_seg_boundary(dev) >> page_shift) + 1;
>
> Can it be better to do something like
> unsigned long boundary = dev ? dma_get_seg_boundary(dev) : U32_MAX;
>
> return (boundary >> page_shift) + 1;
>
> ?
I don't really see what that would buy us.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>,
Christoph Hellwig <hch@lst.de>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
"open list:LINUX FOR POWERPC PA SEMI PWRFICIENT"
<linuxppc-dev@lists.ozlabs.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
rth@twiddle.net, ink@jurassic.park.msu.ru,
Matt Turner <mattst88@gmail.com>,
linux-alpha@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-ia64@vger.kernel.org, schnelle@linux.ibm.com,
gerald.schaefer@linux.ibm.com, hca@linux.ibm.com,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
linux-s390@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
sparclinux@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Helge Deller <deller@gmx.de>,
linux-parisc@vger.kernel.org
Subject: Re: [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages()
Date: Thu, 3 Sep 2020 18:12:52 +0200 [thread overview]
Message-ID: <20200903161252.GA24841@lst.de> (raw)
In-Reply-To: <CAHp75VcVJBSnPQ6NfdF8FdEDfM+oQ=Sr+cH5VGX4SrAqrgpf-g@mail.gmail.com>
On Thu, Sep 03, 2020 at 01:57:39PM +0300, Andy Shevchenko wrote:
> > +{
> > + if (!dev)
> > + return (U32_MAX >> page_shift) + 1;
> > + return (dma_get_seg_boundary(dev) >> page_shift) + 1;
>
> Can it be better to do something like
> unsigned long boundary = dev ? dma_get_seg_boundary(dev) : U32_MAX;
>
> return (boundary >> page_shift) + 1;
>
> ?
I don't really see what that would buy us.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: linux-ia64@vger.kernel.org,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Paul Mackerras <paulus@samba.org>,
"H. Peter Anvin" <hpa@zytor.com>,
sparclinux@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Helge Deller <deller@gmx.de>,
"maintainer:X86 ARCHITECTURE \(32-BIT AND 64-BIT\)"
<x86@kernel.org>, Christian Borntraeger <borntraeger@de.ibm.com>,
Ingo Molnar <mingo@redhat.com>, Matt Turner <mattst88@gmail.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Vasily Gorbik <gor@linux.ibm.com>,
schnelle@linux.ibm.com, hca@linux.ibm.com,
Nicolin Chen <nicoleotsuka@gmail.com>,
ink@jurassic.park.msu.ru, Thomas Gleixner <tglx@linutronix.de>,
gerald.schaefer@linux.ibm.com, rth@twiddle.net,
Tony Luck <tony.luck@intel.com>,
linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-alpha@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
"open list:LINUX FOR POWERPC PA SEMI PWRFICIENT"
<linuxppc-dev@lists.ozlabs.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages()
Date: Thu, 3 Sep 2020 18:12:52 +0200 [thread overview]
Message-ID: <20200903161252.GA24841@lst.de> (raw)
In-Reply-To: <CAHp75VcVJBSnPQ6NfdF8FdEDfM+oQ=Sr+cH5VGX4SrAqrgpf-g@mail.gmail.com>
On Thu, Sep 03, 2020 at 01:57:39PM +0300, Andy Shevchenko wrote:
> > +{
> > + if (!dev)
> > + return (U32_MAX >> page_shift) + 1;
> > + return (dma_get_seg_boundary(dev) >> page_shift) + 1;
>
> Can it be better to do something like
> unsigned long boundary = dev ? dma_get_seg_boundary(dev) : U32_MAX;
>
> return (boundary >> page_shift) + 1;
>
> ?
I don't really see what that would buy us.
next prev parent reply other threads:[~2020-09-03 16:12 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-01 22:16 [PATCH 0/2] dma-mapping: update default segment_boundary_mask Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-01 22:16 ` [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages() Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-03 3:47 ` Michael Ellerman
2020-09-03 3:47 ` Michael Ellerman
2020-09-03 3:47 ` Michael Ellerman
2020-09-03 10:57 ` Andy Shevchenko
2020-09-03 10:57 ` Andy Shevchenko
2020-09-03 10:57 ` Andy Shevchenko
2020-09-03 10:57 ` Andy Shevchenko
2020-09-03 16:12 ` Christoph Hellwig [this message]
2020-09-03 16:12 ` Christoph Hellwig
2020-09-03 16:12 ` Christoph Hellwig
2020-09-03 16:12 ` Christoph Hellwig
2020-09-03 17:53 ` Christophe Leroy
2020-09-03 17:53 ` Christophe Leroy
2020-09-03 17:53 ` Christophe Leroy
2020-09-03 17:53 ` Christophe Leroy
2020-09-01 22:16 ` [PATCH 2/2] dma-mapping: set default segment_boundary_mask to ULONG_MAX Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-01 22:16 ` Nicolin Chen
2020-09-02 8:13 ` [PATCH 0/2] dma-mapping: update default segment_boundary_mask Niklas Schnelle
2020-09-02 8:13 ` Niklas Schnelle
2020-09-02 8:13 ` Niklas Schnelle
2020-09-03 3:26 ` Nicolin Chen
2020-09-03 3:26 ` Nicolin Chen
2020-09-03 3:26 ` Nicolin Chen
2020-09-03 16:13 ` Christoph Hellwig
2020-09-03 16:13 ` Christoph Hellwig
2020-09-03 16:13 ` Christoph Hellwig
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