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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Rspamd-Queue-Id: 8F99DC0006 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 6oy5c844hbuapokw5sh8rujx5ys5wgch X-HE-Tag: 1674255570-487232 X-HE-Meta: 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 4+JGlYSf pQJpm0BJMkdvsFP9dJuPRWVx2qMmoZFWlG/mgJjmYgiejRLy/Blqd2yBJsw8DYbxCz5ULcmVfpQahTMdwFWPWMVNgD0C/lVLozPOqJnnbni7/4FP3NO8zBzCTpOZ55a/GS/nR2y63QXijYAdMEzBH1A8RVgWJtOaU/Mfg0NkOqz4nWMs29A9bx0Sjkhvfy4v/m0kk8/pAli7Y9bimUJxIYoW4vOjtUBYlvhJoAGKDQGTwMNWna27YNLcLdwKwWafEaDTSKe6MmYkN5g9FmAJ9udYmPVfCh1xZSM6NmdkUFlNX7t0BO3zogF3ge62+RXFWUjFSf8wYW0GmpDevrjhDMoHeGQr9JOAsRKJcOCAlarzjqw8= 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 1/21/23 12:14 AM, Greg KH wrote: > On Fri, Jan 20, 2023 at 01:57:27PM +0800, Gavin Shan wrote: >> Use an array to show memory block state from '/sys/devices/system/ >> memory/memoryX/state', to simplify the code. >> >> No functional change intended. >> >> Signed-off-by: Gavin Shan >> --- >> drivers/base/memory.c | 25 ++++++------------------- >> 1 file changed, 6 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index b456ac213610..9474f25c452c 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -141,28 +141,15 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr, >> char *buf) >> { >> struct memory_block *mem = to_memory_block(dev); >> - const char *output; >> + static const char *const mem_state_str[] = { >> + NULL, "online", "going-offline", NULL, "offline", >> + }; >> >> - /* >> - * We can probably put these states in a nice little array >> - * so that they're not open-coded >> - */ >> - switch (mem->state) { >> - case MEM_ONLINE: >> - output = "online"; >> - break; >> - case MEM_OFFLINE: >> - output = "offline"; >> - break; >> - case MEM_GOING_OFFLINE: >> - output = "going-offline"; >> - break; >> - default: >> - WARN_ON(1); >> + if (WARN_ON(mem->state >= ARRAY_SIZE(mem_state_str) || >> + !mem_state_str[mem->state])) > > Ick, the whole WARN_ON() should just be removed please. We don't want > to reboot any systems if this changed incorrectly. > > Please fix this up to properly handle this and keep going on, don't mess > with WARN_ON() anymore in code that can recover properly. > Thanks for your review, Greg. Indeed, the WARN_ON() here is no sense because the warning can be caught from the return value. "ERROR-UNKNOWN-%ld\n" is returned for unknown or invalid state. I will drop WARN_ON() in v2. PATCH[1/2] won't be reposted since it has been merged to driver.core git tree. Thanks, Gavin