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[2003:cb:c703:d00:ca74:d9ea:11e0:dfb]) by smtp.gmail.com with ESMTPSA id fc6-20020a05600c524600b003ee04190ddfsm8292351wmb.17.2023.03.22.04.12.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Mar 2023 04:12:10 -0700 (PDT) Message-ID: Date: Wed, 22 Mar 2023 12:12:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v4 2/4] fs/proc/kcore: convert read_kcore() to read_kcore_iter() To: Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton Cc: Baoquan He , Uladzislau Rezki , Matthew Wilcox , Liu Shixin , Jiri Olsa , Jens Axboe , Alexander Viro References: From: David Hildenbrand Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: AA6E114001A X-Stat-Signature: 5gnrub15859xnw3pdkdpe4a5m9yk3kek X-Rspam-User: X-HE-Tag: 1679483534-475401 X-HE-Meta: U2FsdGVkX19b7CP3L7WPvvEYVaN3bywLuUMQLR7QHUrlXypp9DJzsmjXUflDISjr2mave3PacgkcxsY+xkyN365xAQ7qrH9w4Q419If/+mWf5dOPlXUq38NQFx57rVE+SVd/8sGwtSkP4RyX36+hsviL3sMw5K8Ls/qLOuBJEPQYaAiQtZnO7gdJy3bwsLzRGJmkrBJf9o99OKH39aI6Mhex6jRtJ2PX3hy909jXz56Tfj2R42+Hh818SY40wIAYaoIiq8BF3lfwwFseMbJa6Z4WyH4zxapJ4v+IGWQMhqSn60oQlIlFO5GXaqChxZKNvh3tHmwFpX9UjsoyzcXy0nrQITaJqQLge7cSNyHH7Z4Fuvwmua6T1T/2rVldv9CTs+IeTTr7fs7jhdiUZZuXvKSnBv/U+TjkZEUFQAZKN/m6blUxbZEVx4vF/AZZ0kzirtCUWFdMBEd+OkHEvj7AfFbuHUs5D0Czrj5tYlJ7/xkSc/fGxpgW7mHfL4uKa7X+VabhUZMD0hugENLyoEXrT+RlxSyv0UAUV26BSVLkheXoVZOCDVfw+m24NQOoSom5VF8kQD1Ox3URrdtV+IP+Re121+0zeqUBD1/B5sg2PIU0eVEofs8b8Cd2LbcUSXiQaVOdu8GgcY4AJ6Bqa1zEgXS8f6Rg7/PzHVMYEH0lZl2V6T+RalX2hxiVkFadpv3j0EffvWm+F/pa7lzQ7HMw5SsEd7y0hOeJR/S1gZQ42GHGC+hJLeiyyQeSd43Y34V5JaF+PXi88jpKHQJSoLmSzMujFCjGxq/bqLn9WJHbF415AZMPCzshKDUMtd2Bhl38p4XRp32Ye/FwGeP9tlJHVut1792/jNS4EwKs/qPirdZX+HtD8tTKEThjepLJFnC2iV30ElnqyF11PlAYvRySnLtn86XuGtrY7uIxBQ6nQSXC6bLPcY2qeU8Y+SUU+0CAEuNCrgnAhedoqRRPFxY 4cxdKrcm 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 21.03.23 21:54, Lorenzo Stoakes wrote: > Now we have eliminated spinlocks from the vread() case, convert > read_kcore() to read_kcore_iter(). > > For the time being we still use a bounce buffer for vread(), however in the > next patch we will convert this to interact directly with the iterator and > eliminate the bounce buffer altogether. > > Signed-off-by: Lorenzo Stoakes > --- > fs/proc/kcore.c | 58 ++++++++++++++++++++++++------------------------- > 1 file changed, 29 insertions(+), 29 deletions(-) > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index 556f310d6aa4..25e0eeb8d498 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -24,7 +24,7 @@ > #include > #include > #include > -#include > +#include > #include > #include > #include > @@ -308,9 +308,12 @@ static void append_kcore_note(char *notes, size_t *i, const char *name, > } > > static ssize_t > -read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) > +read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter) > { > + struct file *file = iocb->ki_filp; > char *buf = file->private_data; > + loff_t *ppos = &iocb->ki_pos; Not renaming fpos -> ppos in this patch would result in less noise in this patch. Just like you didn't rename buflen. In general, LGTM Reviewed-by: David Hildenbrand -- Thanks, David / dhildenb