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b=WNVYon2c7VTFWQGDORJfI135bNGLrZIyVS6PYqzKr0T52GWoSlkdZW7KTnKd6u/r+ TquGsv01GkbqExIbNU96vxAvvqK15dFlp1rNJhY7y/obqQ6eOjIOHFMX+cW8CJ8Wim McUk4ej/jiRea1PcZG6s3NqkcstFCNUZ95wzKd21r7FBDS8zMv+afGINi/geYMo5xk Tp7cOYsfec2EWV2P8Gyi5SwUk9pKzLmkxRooB4pbRUgMwMDwCmp4rSi8llR9zb4opd za79X6/+7vF/W+n5s09mFuut7FFQRXn64MYP2mv8BJifTqziEGrbsliRY6yCyxfuUn sE5Y2awZoVtUA== Message-ID: Date: Wed, 8 Jul 2026 18:32:23 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/slab: extract __free_to_pcs_batch() from free_to_pcs_bulk() Content-Language: en-US To: hu.shengming@zte.com.cn Cc: harry@kernel.org, akpm@linux-foundation.org, hao.li@linux.dev, cl@gentwo.org, rientjes@google.com, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260707233433577tAGELJALunrdd2lZy83V-@zte.com.cn> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <20260707233433577tAGELJALunrdd2lZy83V-@zte.com.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 0DB0C180010 X-Stat-Signature: zb3y8fzg7mycj3kzdhkyhocsbumorx4r X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1783528347-703511 X-HE-Meta: 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 QKfK7u0n y0cp8EpWAe6H/usQrd1Szb+s5CftEtGCKQnVt5bqWqDibhVrQ004rzEkxIj3gN5Nbnlx1r8jZv+6D4+qLDEujo2VVM8su7JF5rMdEBhRijfZ53m39b+90WULMjMAUzoYYMIzutwDg6TfHCud8WNsplO1EiCkljnMoFftuvkm3hJ5VMFa8qzzo+DSfjq6MZqvUWmRxutVLP1iUFrFJf9n2LktyWw8Dn/M8dopnTkpGwd6hXM0++B+Du8K6bc3mxaVPvb/DI0NU5R/F4KlPTRfXmM+7wkBdKLpgBeHHXYZQRiqdp2pfgcEzXb0YLSTv79EDwTAzsWTu2UbrOM7IgmxFyUw8R2bDhsXs9lTFc0LcdYz8Bw8= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/7/26 17:34, hu.shengming@zte.com.cn wrote: > Vlastimil wrote: >> It has been noted that free_to_pcs_bulk() is difficult to follow, with a >> number of goto labels, and this has contributed to two memory leak bugs >> in there. >> >> Extract part of the code to __free_to_pcs_batch(), which focuses only on >> freeing free-hook-processed local objects to a percpu sheaf, and >> returning how many were freed. Zero means a trylock failure or no empty >> sheaf available, and thus the caller should fallback to >> __kmem_cache_free_bulk(). >> >> Make free_to_pcs_bulk() call this in a while loop, removing all goto >> labels from the function. __free_to_pcs_batch() retains two rather >> straightforward ones. > > Hi Vlastimil, > > This looks like a very nice refactoring to me. Splitting out the actual > per-CPU sheaf batching into __free_to_pcs_batch() makes the control flow > in free_to_pcs_bulk() much easier to follow, and also keeps the fallback > handling clearer. > > Please feel free to add: > Reviewed-by: Shengming Hu Thanks! Added to slab/for-next