From: Guo Ren <guoren@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
Russell King <linux@armlinux.org.uk>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Nick Hu <nickhu@andestech.com>, Greentime Hu <green.hu@gmail.com>,
Vincent Chen <deanbo422@gmail.com>, Helge Deller <deller@gmx.de>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>, Geoff Levand <geoff@infradead.org>,
Paul Cercueil <paul@crapouillou.net>,
Ulf Hansson <ulf.hansson@linaro.org>, Alex Shi <alexs@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-csky@vger.kernel.org, linux-mips@vger.kernel.org,
linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org,
linux-mmc@vger.kernel.org, linux-scsi@vger.kernel.org,
Linux-MM <linux-mm@kvack.org>,
linux-doc@vger.kernel.org
Subject: Re: flush_kernel_dcache_page fixes and removal
Date: Wed, 14 Jul 2021 11:13:10 +0800 [thread overview]
Message-ID: <CAJF2gTRaRp2nVKGp3+vVnQ3RCvaDxsgHh_vhPTuOxnT51XBXFg@mail.gmail.com> (raw)
In-Reply-To: <20210712060928.4161649-1-hch@lst.de>
Acked-by for csky abiv1 part.(No change to our execution path after
the patch set.)
On Mon, Jul 12, 2021 at 2:10 PM Christoph Hellwig <hch@lst.de> wrote:
>
> Hi all,
>
> while looking to convert the block layer away from kmap_atomic towards
> kmap_local_page and prefeably the helpers that abstract it away I noticed
> that a few block drivers directly or implicitly call
> flush_kernel_dcache_page before kunmapping a page that has been written
> to. flush_kernel_dcache_page is documented to to be used in such cases,
> but flush_dcache_page is actually required when the page could be in
> the page cache and mapped to userspace, which is pretty much always the
> case when kmapping an arbitrary page. Unfortunately the documentation
> doesn't exactly make that clear, which lead to this misused. And it turns
> out that only the copy_strings / copy_string_kernel in the exec code
> were actually correct users of flush_kernel_dcache_page, which is why
> I think we should just remove it and eat the very minor overhead in
> exec rather than confusing poor driver writers.
>
> Diffstat:
> Documentation/core-api/cachetlb.rst | 86 +++++++----------
> Documentation/translations/zh_CN/core-api/cachetlb.rst | 9 -
> arch/arm/include/asm/cacheflush.h | 4
> arch/arm/mm/flush.c | 33 ------
> arch/arm/mm/nommu.c | 6 -
> arch/csky/abiv1/cacheflush.c | 11 --
> arch/csky/abiv1/inc/abi/cacheflush.h | 4
> arch/mips/include/asm/cacheflush.h | 8 -
> arch/nds32/include/asm/cacheflush.h | 3
> arch/nds32/mm/cacheflush.c | 9 -
> arch/parisc/include/asm/cacheflush.h | 8 -
> arch/parisc/kernel/cache.c | 3
> arch/sh/include/asm/cacheflush.h | 8 -
> block/blk-map.c | 2
> drivers/block/ps3disk.c | 2
> drivers/mmc/host/jz4740_mmc.c | 4
> drivers/mmc/host/mmc_spi.c | 2
> drivers/scsi/aacraid/aachba.c | 1
> fs/exec.c | 6 -
> include/linux/highmem.h | 5
> lib/scatterlist.c | 5
> tools/testing/scatterlist/linux/mm.h | 1
> 22 files changed, 55 insertions(+), 165 deletions(-)
--
Best Regards
Guo Ren
ML: https://lore.kernel.org/linux-csky/
prev parent reply other threads:[~2021-07-14 3:13 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-12 6:09 flush_kernel_dcache_page fixes and removal Christoph Hellwig
2021-07-12 6:09 ` [PATCH 1/6] mmc: JZ4740: remove the flush_kernel_dcache_page call in jz4740_mmc_read_data Christoph Hellwig
2021-07-19 8:15 ` Paul Cercueil
2021-08-04 11:12 ` Ulf Hansson
2021-07-12 6:09 ` [PATCH 2/6] mmc: mmc_spi: replace flush_kernel_dcache_page with flush_dcache_page Christoph Hellwig
2021-08-04 11:12 ` Ulf Hansson
2021-07-12 6:09 ` [PATCH 3/6] ps3disk: " Christoph Hellwig
2021-07-19 3:07 ` Geoff Levand
2021-07-12 6:09 ` [PATCH 4/6] scatterlist: " Christoph Hellwig
2021-07-12 6:09 ` [PATCH 5/6] aacraid: remove an unused include Christoph Hellwig
2021-07-19 1:50 ` Martin K. Petersen
2021-07-12 6:09 ` [PATCH 6/6] mm: remove flush_kernel_dcache_page Christoph Hellwig
2021-07-12 23:56 ` Ira Weiny
2021-07-12 19:24 ` flush_kernel_dcache_page fixes and removal Linus Torvalds
2021-07-13 5:46 ` Christoph Hellwig
2021-07-13 8:46 ` Russell King (Oracle)
2021-07-13 9:11 ` Christoph Hellwig
2021-07-19 5:38 ` Herbert Xu
2021-07-19 15:42 ` Russell King (Oracle)
2021-07-14 3:13 ` Guo Ren [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAJF2gTRaRp2nVKGp3+vVnQ3RCvaDxsgHh_vhPTuOxnT51XBXFg@mail.gmail.com \
--to=guoren@kernel.org \
--cc=James.Bottomley@hansenpartnership.com \
--cc=akpm@linux-foundation.org \
--cc=alexs@kernel.org \
--cc=dalias@libc.org \
--cc=deanbo422@gmail.com \
--cc=deller@gmx.de \
--cc=geoff@infradead.org \
--cc=green.hu@gmail.com \
--cc=hch@lst.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-csky@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-parisc@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=nickhu@andestech.com \
--cc=paul@crapouillou.net \
--cc=torvalds@linux-foundation.org \
--cc=tsbogend@alpha.franken.de \
--cc=ulf.hansson@linaro.org \
--cc=ysato@users.sourceforge.jp \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).