From: Xin Li <xin@zytor.com>
To: Ethan Zhao <haifeng.zhao@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ethan Zhao <etzhao@outlook.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: tglx@linutronix.de, dave.hansen@linux.intel.com, x86@kernel.org,
andrew.cooper3@citrix.com, mingo@redhat.com, bp@alien8.de
Subject: Re: [PATCH] x86/fred: Optimize the FRED entry by prioritizing high-probability event dispatching
Date: Thu, 16 Jan 2025 21:54:35 -0800 [thread overview]
Message-ID: <d96d60b9-fa17-4981-a7e9-1b8bab1a7eed@zytor.com> (raw)
In-Reply-To: <33b89995-b638-4a6b-a75f-8278562237c4@linux.intel.com>
On 1/16/2025 9:18 PM, Ethan Zhao wrote:
>>
>> Just swap the 2 arguments, and it should be:
>> + switch_likely (etype, EVENT_TYPE_OTHER) {
>>
>>
> after swapped the parameters as following:
> +#define switch_likely(v,l) \
> + switch((__typeof__(v))__builtin_expect((v),(l)))
> +
> __visible noinstr void fred_entry_from_user(struct pt_regs *regs)
> {
> unsigned long error_code = regs->orig_ax;
> + unsigned short etype = regs->fred_ss.type & 0xf;
>
> /* Invalidate orig_ax so that syscall_get_nr() works correctly */
> regs->orig_ax = -1;
>
> - switch (regs->fred_ss.type) {
> + switch_likely (etype, (EVENT_TYPE_EXTINT == etype ||
> EVENT_TYPE_OTHER == etype)) {
This is not what I suggested, the (l) argument should be only one
constant; __builtin_expect() doesn't allow 2 different constants.
next prev parent reply other threads:[~2025-01-17 5:55 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-16 6:51 [PATCH] x86/fred: Optimize the FRED entry by prioritizing high-probability event dispatching Ethan Zhao
2025-01-16 7:27 ` Xin Li
2025-01-16 9:22 ` Ethan Zhao
2025-01-16 13:03 ` Ethan Zhao
2025-01-16 13:48 ` Xin Li
2025-01-17 0:37 ` Ethan Zhao
2025-01-17 1:21 ` H. Peter Anvin
2025-01-17 3:04 ` Ethan Zhao
2025-01-17 4:19 ` Ethan Zhao
2025-01-17 4:43 ` Xin Li
2025-01-17 5:18 ` Ethan Zhao
2025-01-17 5:54 ` Xin Li [this message]
2025-01-17 6:58 ` Ethan Zhao
2025-01-17 16:17 ` H. Peter Anvin
2025-01-17 16:23 ` H. Peter Anvin
2025-01-18 4:00 ` Ethan Zhao
2025-01-17 16:24 ` H. Peter Anvin
2025-01-18 3:29 ` Ethan Zhao
2025-01-18 3:41 ` H. Peter Anvin
2025-01-18 4:06 ` Ethan Zhao
2025-01-18 4:09 ` H. Peter Anvin
2025-01-18 5:55 ` Ethan Zhao
2025-01-18 4:14 ` H. Peter Anvin
2025-01-18 6:02 ` Ethan Zhao
2025-01-16 15:08 ` Nikolay Borisov
2025-01-16 18:45 ` Xin Li
2025-01-17 0:40 ` Ethan Zhao
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