Date: Mon, 12 May 2025 17:46:51 GMT From: =?utf-8?Q?Jean-S=C3=A9bastien?= =?utf-8?Q?P=C3=A9dron?= <dumbbell@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: c8089810a940 - main - linuxkpi: Make "free page" code paths closer to Linux Message-ID: <202505121746.54CHkpwR035372@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by dumbbell: URL: https://cgit.FreeBSD.org/src/commit/?id=c8089810a94027b7f937b9e63d2d8d31a02aaac5 commit c8089810a94027b7f937b9e63d2d8d31a02aaac5 Author: Jean-Sébastien Pédron <dumbbell@FreeBSD.org> AuthorDate: 2025-04-13 11:13:17 +0000 Commit: Jean-Sébastien Pédron <dumbbell@FreeBSD.org> CommitDate: 2025-05-12 17:08:02 +0000 linuxkpi: Make "free page" code paths closer to Linux There is basically one code path to free pages on Linux. In particular, `free_pages()` is used for other pages than those returned by `alloc_pages()`. Also on Linux, `release_pages()` takes either `struct page` or `struct folio`. `struct folio` support will be added in a followup commit. Regardless, because pages come from several sources, `linux_free_pages()` need to accept managed and unmanaged pages. Reviewed by: bz, markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D49813 --- sys/compat/linuxkpi/common/include/linux/mm.h | 3 ++- sys/compat/linuxkpi/common/src/linux_page.c | 22 +++++++++++++++++++--- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h index f523395cc71c..569e2a8b70f1 100644 --- a/sys/compat/linuxkpi/common/include/linux/mm.h +++ b/sys/compat/linuxkpi/common/include/linux/mm.h @@ -278,7 +278,8 @@ get_page(struct page *page) static inline void put_page(struct page *page) { - vm_page_unwire(page, PQ_ACTIVE); + /* `__free_page()` takes care of the refcounting (unwire). */ + __free_page(page); } void linux_release_pages(struct page **pages, int nr); diff --git a/sys/compat/linuxkpi/common/src/linux_page.c b/sys/compat/linuxkpi/common/src/linux_page.c index c299457f042a..7ce52cbf95eb 100644 --- a/sys/compat/linuxkpi/common/src/linux_page.c +++ b/sys/compat/linuxkpi/common/src/linux_page.c @@ -165,8 +165,24 @@ linux_free_pages(struct page *page, unsigned int order) for (x = 0; x != npages; x++) { vm_page_t pgo = page + x; - if (vm_page_unwire_noq(pgo)) - vm_page_free(pgo); + /* + * The "free page" function is used in several + * contexts. + * + * Some pages are allocated by `linux_alloc_pages()` + * above, but not all of them are. For instance in the + * DRM drivers, some pages come from + * `shmem_read_mapping_page_gfp()`. + * + * That's why we need to check if the page is managed + * or not here. + */ + if ((pgo->oflags & VPO_UNMANAGED) == 0) { + vm_page_unwire(pgo, PQ_ACTIVE); + } else { + if (vm_page_unwire_noq(pgo)) + vm_page_free(pgo); + } } } else { vm_offset_t vaddr; @@ -183,7 +199,7 @@ linux_release_pages(struct page **pages, int nr) int i; for (i = 0; i < nr; i++) - put_page(pages[i]); + __free_page(pages[i]); } vm_offset_t
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202505121746.54CHkpwR035372>