From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HnM4jinW" Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37B678E for ; Tue, 12 Dec 2023 09:22:38 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id d9443c01a7336-1d08383e566so52692255ad.2 for ; Tue, 12 Dec 2023 09:22:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702401758; x=1703006558; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ROCp0xNd0wyqOc7nplsrZkpuLfarMjHYIQNZwVviJ7k=; b=HnM4jinWoc7Y5b/wDcbxzJJepOv8cd4sO9RdKKADcqamDAueL8wrV0FHrWCfx3snha kb3yVOaEw20XaycdieaS9+JG3aDqvlg3rMLHPzUvrdZKKe+oObuCjpJh2kMuUU5v9xvT JbNB8Mfz5t85NmrqChVZgfsHz4/BQWiKq3Mekmx+fjBNSN5zFViZCwlKvVQx0hSmvPYO boqVaOAw0oI+3miZYt2kJU5fOatMy3jMXyJhVmgtoCpjfSy4xxzxdGN7eE0PDdnLo1OI Yo7RpJkmZDIhye5U5vsp5WjHIvgK1t98NzSPOJJq23OGuGmyh5cH+EGutSl2icqNBXHA uB7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702401758; x=1703006558; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ROCp0xNd0wyqOc7nplsrZkpuLfarMjHYIQNZwVviJ7k=; b=bh2prSV2dT2ozYHhUuBTdpzB3XfMYdXjQg4/XpOJ5ksxp3Auivnq1RzW815wHVX36B HS2K+1hJV2hakbj4MIxGV3XWVpoKYJV9hFj9WyUprJioXw6xu9ad2GXyb2RiKa22dUZr TQxKy0osJJklQX+wp68n17j2R/dsZYh8HimH4pmv07IPGYjWKcJYPRWRBET9wsxTpnKO qZlpRjq4X6kHcBJISJdRkWNfAQYUqkLgqLw7JoayjiC+picx2leO3h5XB5cPMDKT8ByG v3flYZxH+lfrkkAhJP6cki0IPmD/8ZBcLe5naoCsHudx8iS5upWUhP8wzKQSagd4EKwT zMMA== X-Gm-Message-State: AOJu0YwHXBAOeVR5fHPosTsO/LuZ92vwiIEs9ocw1kblNWoxwnWTLB9i lIeFofh/8bUH47beViribL9VrYtBhFQ= X-Google-Smtp-Source: AGHT+IEOEh3C8zTlAW12bJONZI+u1CmuqqelXRvUx1auEKYIObXd3RFyfjdun8PThEpN5T5kS2y4fIeGI98= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:a504:b0:1d0:54ff:da25 with SMTP id s4-20020a170902a50400b001d054ffda25mr46568plq.0.1702401757577; Tue, 12 Dec 2023 09:22:37 -0800 (PST) Date: Tue, 12 Dec 2023 09:22:36 -0800 In-Reply-To: <20231212022749.625238-14-yury.norov@gmail.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231212022749.625238-1-yury.norov@gmail.com> <20231212022749.625238-14-yury.norov@gmail.com> Message-ID: Subject: Re: [PATCH v3 13/35] KVM: x86: hyper-v: optimize and cleanup kvm_hv_process_stimers() From: Sean Christopherson To: Yury Norov Cc: linux-kernel@vger.kernel.org, Vitaly Kuznetsov , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , kvm@vger.kernel.org, Jan Kara , Mirsad Todorovac , Matthew Wilcox , Rasmus Villemoes , Andy Shevchenko , Maxim Kuvyrkov , Alexey Klimov , Bart Van Assche , Sergey Shtylyov Content-Type: text/plain; charset="us-ascii" On Mon, Dec 11, 2023, Yury Norov wrote: > The function traverses stimer_pending_bitmap in a for-loop bit by bit. > Simplify it by using atomic find_and_set_bit(). for_each_test_and_clear_bit(), not find_and_set_bit(). It might also be nice to call out that there are only 4 bits, i.e. that using for_each_test_and_clear_bit() will still generate inline code. Definitely not mandatory though, just nice to have (I highly doubt this code would be sensitive to using less optimal code). > While here, refactor the logic by decreasing indentation level. > > CC: Sean Christopherson > Signed-off-by: Yury Norov > Reviewed-by: Vitaly Kuznetsov > --- > arch/x86/kvm/hyperv.c | 40 ++++++++++++++++++++-------------------- This doesn't conflict with any of the in-flight Hyper-V changes, so with a fixed changelog, feel free to take this through the bitmap tree. Acked-by: Sean Christopherson