From: Amit Singh Tomar <amitsinght@marvell.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- At the moment, number of resource control group (user can create) is limited to 32. Remove the limit. ffs() returns '1' for bit 0, hence the existing code subtracts 1 from the index to get the CLOSID value. find_first_bit() returns the bit number which does not need adjusting. Signed-off-by: Amit Singh Tomar <amitsinght@marvell.com> [ morse: fixed the off-by-one in the allocator and the wrong not-found value. Removed the limit. ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- drivers/platform/mpam/mpam_resctrl.c | 2 +- fs/resctrl/rdtgroup.c | 25 +++++++++++++------------ include/linux/resctrl.h | 5 ----- 3 files changed, 14 insertions(+), 18 deletions(-) diff --git a/drivers/platform/mpam/mpam_resctrl.c b/drivers/platform/mpam/mpam_resctrl.c index 9e69e0e1bb07..38e53c46a9ec 100644 --- a/drivers/platform/mpam/mpam_resctrl.c +++ b/drivers/platform/mpam/mpam_resctrl.c @@ -132,7 +132,7 @@ static bool mpam_resctrl_hide_cdp(enum resctrl_res_level rid) */ u32 resctrl_arch_get_num_closid(struct rdt_resource *ignored) { - return min((u32)mpam_partid_max + 1, (u32)RESCTRL_MAX_CLOSID); + return mpam_partid_max + 1; } u32 resctrl_arch_system_num_rmid_idx(void) diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 427aa26dc006..79d994fa813f 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -123,8 +123,8 @@ static bool resctrl_is_mbm_event(int e) } /* - * Trivial allocator for CLOSIDs. Since h/w only supports a small number, - * we can keep a bitmap of free CLOSIDs in a single integer. + * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap + * of free CLOSIDs. * * Using a global CLOSID across all resources has some advantages and * some drawbacks: @@ -137,7 +137,7 @@ static bool resctrl_is_mbm_event(int e) * - Our choices on how to configure each resource become progressively more * limited as the number of resources grows. */ -static unsigned long closid_free_map; +static unsigned long *closid_free_map; static int closid_free_map_len; int closids_supported(void) @@ -148,16 +148,17 @@ int closids_supported(void) static void closid_init(void) { struct resctrl_schema *s; - u32 rdt_min_closid = 32; + u32 rdt_min_closid = ~0; /* Compute rdt_min_closid across all resources */ list_for_each_entry(s, &resctrl_schema_all, list) rdt_min_closid = min(rdt_min_closid, s->num_closid); - closid_free_map = BIT_MASK(rdt_min_closid) - 1; + closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL); + bitmap_fill(closid_free_map, rdt_min_closid); /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ - __clear_bit(RESCTRL_RESERVED_CLOSID, &closid_free_map); + __clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map); closid_free_map_len = rdt_min_closid; } @@ -174,12 +175,12 @@ static int closid_alloc(void) return cleanest_closid; closid = cleanest_closid; } else { - closid = ffs(closid_free_map); - if (closid == 0) + closid = find_first_bit(closid_free_map, closid_free_map_len); + if (closid == closid_free_map_len) return -ENOSPC; - closid--; } - __clear_bit(closid, &closid_free_map); + + __clear_bit(closid, closid_free_map); return closid; } @@ -188,7 +189,7 @@ void closid_free(int closid) { lockdep_assert_held(&rdtgroup_mutex); - __set_bit(closid, &closid_free_map); + __set_bit(closid, closid_free_map); } /** @@ -202,7 +203,7 @@ bool closid_allocated(unsigned int closid) { lockdep_assert_held(&rdtgroup_mutex); - return !test_bit(closid, &closid_free_map); + return !test_bit(closid, closid_free_map); } /** diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 35c3bf2ec599..bd419324e822 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -30,11 +30,6 @@ int proc_resctrl_show(struct seq_file *m, /* max value for struct rdt_domain's mbps_val */ #define MBA_MAX_MBPS U32_MAX -/* - * Resctrl uses a u32 as a closid bitmap. The maximum closid is 32. - */ -#define RESCTRL_MAX_CLOSID 32 - /* * Resctrl uses u32 to hold the user-space config. The maximum bitmap size is * 32. -- 2.25.1