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Wed, 08 Apr 2026 16:36:15 -0700 (PDT) Received: from smtpclient.apple ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id 5614622812f47-46d9387a763sm12681031b6e.18.2026.04.08.16.36.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Apr 2026 16:36:14 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Jens Axboe Mime-Version: 1.0 (1.0) Subject: Re: [PATCH RFC v4 1/3] block: add BIO_COMPLETE_IN_TASK for task-context completion Date: Wed, 8 Apr 2026 17:36:03 -0600 Message-Id: <95F28FA1-5CEF-4E80-BBB7-A429B4437D12@kernel.dk> References: <97b81868-6410-4c79-a242-679a9f04f073@columbia.edu> Cc: Matthew Wilcox , Christian Brauner , "Darrick J. Wong" , Carlos Maiolino , Alexander Viro , Jan Kara , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <97b81868-6410-4c79-a242-679a9f04f073@columbia.edu> To: Tal Zussman X-Mailer: iPhone Mail (23E246) X-Rspamd-Queue-Id: 9EBEB1C000A X-Stat-Signature: u1ggeaus9s75gh743mz6336gyc3ohq3y X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1775691376-571592 X-HE-Meta: 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 iiJbpsZn /Apik51oaI+mml+Sg2jRJnW16I4HvoE65T2aieZYenrtABrQH9QCFDMlzOMoiHoQmHYgCyOTTZyy6xyOKmYKDJWfhZQgcA77MEccvPGHtHLfz3qXtuOguQG9EWwst2Wkgu8QZLgx92LsoZYz635s5Jwbxo2mKHX/WK74NjX03vLWWElkxftpoaSeF7uxGTHXG3E5lYyzruWZT+ffrGF2wPk95fBsN00a9Zl7jzO19gpX9VtPtNTYHl7iUkIaCJSgXN+2u0n2yQz5srxB7ssknraHfYP9h2hQX/1zkZd9RqhqwD/ymm+j2a7LEbor6ftOBJsM9cj9uey4mP2kUt/F0QW0wgl+QbG31jM1LwlXpyD96Y9xFjZ9bTmmjELNZgUtTQd+NT1atvONzwTDp5e2RqUhMwK7FbcyIa5EVRWYO5t6Cp53PH7xADsW4PjDY1Vr5NBhN Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Apr 8, 2026, at 4:51=E2=80=AFPM, Tal Zussman wrote:= >=20 > =EF=BB=BF >=20 >> On 4/8/26 3:51 PM, Jens Axboe wrote: >>> On 4/8/26 12:=E2=80=8A48 PM, Tal Zussman wrote: > On 3/25/26 4:=E2=80=8A= 14 PM, Jens Axboe wrote: >>>=20 >>> Thanks! I'm going to give Dave's llist suggestion a shot on top of >>> this as it seems like it'll simplify this nicely. Looks like that'll >>> involve turning bio::bi_next into a union with a struct llist_node. >>=20 >> Since these lists can get long, I'd keep an eye on llist reversal >> overhead there... >>=20 >=20 > Going to send v5 shortly -- tested with and without the llist reversal and= > it didn't seem to make much of a difference. This was on a single-disk VM > though, so any stress testing you could do would be very helpful. >=20 With all due respect, a single test like that isn=E2=80=99t going to be that= useful. I=E2=80=99d be wary of making that change willy nilly and just thin= king =E2=80=9Cit=E2=80=99s fine, worked fine on the one case I tested=E2=80=9D= . =E2=80=94=20 Jens Axboe