The quilt patch titled Subject: mm/damon/core: split out DAMOS-charged region skip logic into a new function has been removed from the -mm tree. Its filename was mm-damon-core-split-out-damos-charged-region-skip-logic-into-a-new-function.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/core: split out DAMOS-charged region skip logic into a new function Date: Wed, 26 Oct 2022 22:59:32 +0000 Patch series "mm/damon: cleanup and refactoring code", v2. This patchset cleans up and refactors a range of DAMON code including the core, DAMON sysfs interface, and DAMON modules, for better readability and convenient future feature implementations. In detail, this patchset splits unnecessarily long and complex functions in core into smaller functions (patches 1-4). Then, it cleans up the DAMON sysfs interface by using more type-safe code (patch 5) and removing unnecessary function parameters (patch 6). Further, it refactor the code by distributing the code into multiple files (patches 7-10). Last two patches (patches 11 and 12) deduplicates and remove unnecessary header inclusion in DAMON modules (reclaim and lru_sort). This patch (of 12): The DAMOS action applying function, 'damon_do_apply_schemes()', is quite long and not so simple. Split out the already quota-charged region skip code, which is not a small amount of simple code, into a new function with some comments for better readability. Link: https://lkml.kernel.org/r/20221026225943.100429-1-sj@xxxxxxxxxx Link: https://lkml.kernel.org/r/20221026225943.100429-2-sj@xxxxxxxxxx Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/core.c | 96 +++++++++++++++++++++++++++++++--------------- 1 file changed, 65 insertions(+), 31 deletions(-) --- a/mm/damon/core.c~mm-damon-core-split-out-damos-charged-region-skip-logic-into-a-new-function +++ a/mm/damon/core.c @@ -694,6 +694,67 @@ static bool damos_valid_target(struct da return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score; } +/* + * damos_skip_charged_region() - Check if the given region or starting part of + * it is already charged for the DAMOS quota. + * @t: The target of the region. + * @rp: The pointer to the region. + * @s: The scheme to be applied. + * + * If a quota of a scheme has exceeded in a quota charge window, the scheme's + * action would applied to only a part of the target access pattern fulfilling + * regions. To avoid applying the scheme action to only already applied + * regions, DAMON skips applying the scheme action to the regions that charged + * in the previous charge window. + * + * This function checks if a given region should be skipped or not for the + * reason. If only the starting part of the region has previously charged, + * this function splits the region into two so that the second one covers the + * area that not charged in the previous charge widnow and saves the second + * region in *rp and returns false, so that the caller can apply DAMON action + * to the second one. + * + * Return: true if the region should be entirely skipped, false otherwise. + */ +static bool damos_skip_charged_region(struct damon_target *t, + struct damon_region **rp, struct damos *s) +{ + struct damon_region *r = *rp; + struct damos_quota *quota = &s->quota; + unsigned long sz_to_skip; + + /* Skip previously charged regions */ + if (quota->charge_target_from) { + if (t != quota->charge_target_from) + return true; + if (r == damon_last_region(t)) { + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + return true; + } + if (quota->charge_addr_from && + r->ar.end <= quota->charge_addr_from) + return true; + + if (quota->charge_addr_from && r->ar.start < + quota->charge_addr_from) { + sz_to_skip = ALIGN_DOWN(quota->charge_addr_from - + r->ar.start, DAMON_MIN_REGION); + if (!sz_to_skip) { + if (damon_sz_region(r) <= DAMON_MIN_REGION) + return true; + sz_to_skip = DAMON_MIN_REGION; + } + damon_split_region_at(t, r, sz_to_skip); + r = damon_next_region(r); + *rp = r; + } + quota->charge_target_from = NULL; + quota->charge_addr_from = 0; + } + return false; +} + static void damon_do_apply_schemes(struct damon_ctx *c, struct damon_target *t, struct damon_region *r) @@ -702,7 +763,7 @@ static void damon_do_apply_schemes(struc damon_for_each_scheme(s, c) { struct damos_quota *quota = &s->quota; - unsigned long sz = damon_sz_region(r); + unsigned long sz; struct timespec64 begin, end; unsigned long sz_applied = 0; @@ -713,41 +774,14 @@ static void damon_do_apply_schemes(struc if (quota->esz && quota->charged_sz >= quota->esz) continue; - /* Skip previously charged regions */ - if (quota->charge_target_from) { - if (t != quota->charge_target_from) - continue; - if (r == damon_last_region(t)) { - quota->charge_target_from = NULL; - quota->charge_addr_from = 0; - continue; - } - if (quota->charge_addr_from && - r->ar.end <= quota->charge_addr_from) - continue; - - if (quota->charge_addr_from && r->ar.start < - quota->charge_addr_from) { - sz = ALIGN_DOWN(quota->charge_addr_from - - r->ar.start, DAMON_MIN_REGION); - if (!sz) { - if (damon_sz_region(r) <= - DAMON_MIN_REGION) - continue; - sz = DAMON_MIN_REGION; - } - damon_split_region_at(t, r, sz); - r = damon_next_region(r); - sz = damon_sz_region(r); - } - quota->charge_target_from = NULL; - quota->charge_addr_from = 0; - } + if (damos_skip_charged_region(t, &r, s)) + continue; if (!damos_valid_target(c, t, r, s)) continue; /* Apply the scheme */ + sz = damon_sz_region(r); if (c->ops.apply_scheme) { if (quota->esz && quota->charged_sz + sz > quota->esz) { _ Patches currently in -mm which might be from sj@xxxxxxxxxx are docs-admin-guide-mm-damon-usage-describe-the-rules-of-sysfs-region-directories.patch docs-admin-guide-mm-damon-usage-fix-wrong-usage-example-of-init_regions-file.patch mm-damon-core-add-a-callback-for-scheme-target-regions-check.patch mm-damon-sysfs-schemes-implement-schemes-tried_regions-directory.patch mm-damon-sysfs-schemes-implement-scheme-region-directory.patch mm-damon-sysfs-implement-damos-tried-regions-update-command.patch mm-damon-sysfs-implement-damos-tried-regions-update-command-fix.patch mm-damon-sysfs-schemes-implement-damos-tried-regions-clear-command.patch mm-damon-sysfs-schemes-implement-damos-tried-regions-clear-command-fix.patch tools-selftets-damon-sysfs-test-tried_regions-directory-existence.patch docs-admin-guide-mm-damon-usage-document-schemes-s-tried_regions-sysfs-directory.patch docs-abi-damon-document-schemes-s-tried_regions-sysfs-directory.patch selftests-damon-test-non-context-inputs-to-rm_contexts-file.patch