From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEADD46AF25; Wed, 3 Jun 2026 17:21:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780507318; cv=none; b=X/cHBkeKA7kXgqWrhdUtfODH+dMzogYsD3Pjoe6xtlTaCFNzzRrxx9e08bUDLYyQvMMaZ66PawQw1tZTkdsllorqJ21TzwHxgHChbwvM+v9XQyFreDf0FSPaHrkclsbMw3Xi9YPYB7z0aDPcvllsySxsgmJ96u+aJ9mo8zltCBE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780507318; c=relaxed/simple; bh=ubeJ4rNQG0Ef6kO6sgM1fpCp8AHwVjx0eI7FQ81ZpGc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OqgUUA7HhEIsBvd4l7Qi4WefqpiROMf6qUMJAal+jY/aCrG2g0s4B7jcVLIuZIkgvTR6/w3mIxqxiSxixDgYMRRjsCUirmxEEwgCYE1MDBu8xxp8QgMgH6wr8xiA2Oi1fLFJ8WZewHTs8j0OqQWHjL9WVg08AAhdtWycfW4+MzU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RJ3yNKM0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RJ3yNKM0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74ADA1F00899; Wed, 3 Jun 2026 17:21:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780507316; bh=RRw0+fHhoSh1DjgvQrikdK70eQbmSg8XU3PleKXE8Bg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RJ3yNKM0SGYzbusZdMzuAf2bUIPR/vliT2xmYcsWCyDy4mnKN4NV534rPHK6z1uoQ sFe3UEgatXgqT+EjfD6gv/oDRvUomiVhbdW0oQlGPLStdpofvasmipL1YalUee2LHV dVtsPs6X4r01V1PrBZV/BsWjVOCI5L6QXm1pj0aVA3eKiHtoAQeOaMbKaB3vxb/LSn 9/J7jOyJOeRVCqCeXhrGv59oHsGYOU+QhQhrUKLZ63ldav9KK6waVI9lfSQXmT8Xvc LPvQaUXhd558hfBRCmgpWepEwg8emxLFZVmuvK0ovgrwAYEa2SjbrtJlMT3/GfVAUn AXbdeB8/mgIsA== From: Tejun Heo To: David Vernet , Andrea Righi , Changwoo Min Cc: Emil Tsalapatis , sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, Tejun Heo Subject: [PATCH 2/3] sched_ext: Add scx_cmask_test() and scx_cmask_for_each_cid() Date: Wed, 3 Jun 2026 07:21:52 -1000 Message-ID: <20260603172153.3081861-3-tj@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260603172153.3081861-1-tj@kernel.org> References: <20260603172153.3081861-1-tj@kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add single-bit test and iterator over set cids in an scx_cmask. Signed-off-by: Tejun Heo --- kernel/sched/ext_cid.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/kernel/sched/ext_cid.h b/kernel/sched/ext_cid.h index 46fd8eda0443..d4c3ebba7416 100644 --- a/kernel/sched/ext_cid.h +++ b/kernel/sched/ext_cid.h @@ -225,4 +225,35 @@ static inline void __scx_cmask_set(u32 cid, struct scx_cmask *m) *__scx_cmask_word(cid, m) |= BIT_U64(cid & 63); } +/** + * scx_cmask_test - test whether @cid is set in @m + * @cid: cid to test + * @m: cmask to test + * + * Return %false if @cid is outside @m's active range. Otherwise return the + * bit's value. Read via READ_ONCE so callers can race set/clear writers. + */ +static inline bool scx_cmask_test(u32 cid, const struct scx_cmask *m) +{ + if (!__scx_cmask_contains(cid, m)) + return false; + return READ_ONCE(*__scx_cmask_word(cid, m)) & BIT_U64(cid & 63); +} + +/** + * scx_cmask_for_each_cid - iterate set cids in @m + * @cid: s32 loop var that receives each set cid in turn + * @m: cmask to iterate + * + * Visits set bits within @m's active range in ascending order. Relies on the + * head/tail-zero invariant of bits[], so no per-cid range check is needed. + */ +#define scx_cmask_for_each_cid(cid, m) \ + for (u64 __bs = (m)->base & ~63u, __wi = 0, \ + __nw = SCX_CMASK_NR_WORDS((m)->nr_cids); \ + __wi < __nw; __wi++) \ + for (u64 __w = READ_ONCE((m)->bits[__wi]); \ + __w && ((cid) = __bs + __wi * 64 + __ffs64(__w), true); \ + __w &= __w - 1) + #endif /* _KERNEL_SCHED_EXT_CID_H */ -- 2.54.0